News 89N

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General News

Mammal Biocontrol: the Hunt Continues

Mammal population control is an emotivesubject, and scientists searching for effec-tive solutions take this into account. The(particularly urban) public tends to viewwith disfavour the notion of furry creaturessuffering a violent or lingering death,although afflicted landowners may see itrather differently. The public is also verychary about the deliberate introduction ofmammalian disease and the possibility ofits spread to nontarget species (includinghumans); species boundaries are no longerconfidently regarded as impregnable.Added to that are growing concerns aboutthe environmental impact of poison baits.The challenge for those charged with con-trolling mammal populations, then, is tocome up with solutions that are effectiveyet meet these constraints.

Elephant (Loxodonta africana) control inAfrica is a good example. Suffering fromthe ravages of poaching in the late twentiethcentury, the elephant became the symbol ofthreatened wildlife in the continent. Yeteffective conservation has led to elephantoverpopulation in some areas. Culling,which has long been practised in parts ofsouthern Africa, has also fallen increas-ingly into disfavour as research on elephantbehaviour has confirmed their intelligenceand revealed the complex and long-livedfamilial links within groups. So researchersbegan to look to other methods. A suitabletechnique must not only be publicly accept-able and effective, but must also take intoaccount nontarget effects on other species.The elephant has few (and only distantly)related species in Africa (the hyraxes), butcontrol of overabundant marsupials in Aus-tralia and pest marsupials New Zealand, forexample, has to address this issue.

Germs and Worms

Historically, the most common approach tomammal control has been to increase mor-tality in the population by culling (e.g.shooting or poison baiting), by spreadingdisease or by exclusion (e.g. fencing). Forintroduced mammals, levels of disease maybe lower than they are in the home range, itspathogen natural enemies having been leftbehind. In this case, a ‘classical’ biologicalcontrol approach is attractive.

Rabbits (Oryctolagus cuniculus) in Aus-tralia have long been exposed to diseases

introduced from their native Europe inefforts to reduce their devastating impact:myxomatosis was released in the 1950s,and the virus responsible for RHD (rabbithaemorrhagic disease or RCD, rabbit cali-civirus disease) escaped from quarantine onWardang Island (South Australia) in late1995. More recently RHD reached NewZealand [see BNI 19(4) (December 1998),99N-101N ‘RHD after one year in NewZealand’].

Control of rabbits by RHD in Australia hasbeen patchy. It is notably poorer in tem-perate areas, and various reasons have beensuggested. Recently, analysis of storedblood for antibodies has suggested thatsome populations may have been exposedto an RHD-like virus before the escape ofRHD from Wardang Island. However, asthere had been no reports of an RHD-likeillness before RHD arrived on the main-land, this mystery virus is assumed to havebeen non-pathogenic. About 50% of bloodsamples that had been taken from rabbitsbefore RHD release had antibodies thatreacted to an RHD coat protein. Blood sam-ples collected from rabbits in an RHD-freearea of central Victoria all had antibodies tothe RHD or an RHD-like virus, and nearlyhalf of these survived what would generallybe expected to be a fatal dose of RHD. Suchantibodies (which can be distinguishedfrom antibodies in a post-RHD survivor)have now been found to be fairly wide-spread in Australian rabbits, andparticularly in populations in the cooler,wetter areas, and this is where RHD-medi-ated control has been least effective.

RHD in New Zealand has persisted andcontinued to suppress rabbit populations inmany areas. In many of these, it hasreturned each year, generally infectingolder cohorts in spring and then the youngof the year in autumn. Reductions of over90% in numbers have been recorded andgenerally about 30% of survivors are serop-ositve [i.e. have antibodies to the disease].In other areas, the disease has returnedevery second year, and here rabbit numbershave increased to about half the densitybefore RHD arrived, with about 20% ofsurvivors being seropositive. At a few sites,the disease has not reduced rabbit numbersand has left a high proportion (up to 80%)of survivors across all age cohorts withantibodies to RHD. As in Australia, NewZealand rabbits appear to have a pre-existing calicivirus as evidenced by sero-

logical tests (but not yet confirmed bygenetic sequencing). However, the evi-dence to date is that this virus does notimpart immunity to RHD, and so is not anexplanation for the high survivorship andhigh prevalence of seropositive rabbits atsome sites. There is evidence that seroposi-tive rabbits can retain virus in their tissues.Thus it is possible that infected survivorsmay remain infectious, and so the possi-bility exists that the high prevalence acrossage cohorts noted above might be due tosome form of longitudinal transmission ofimmunity from mother to young rabbits.

The large decline in rabbit numbers has hadflow-on effects to other parts of New Zea-land ecosystems. Pasture biomassincreased at one study site by 77% whenrabbits declined by 88%. Brushtail possum(Trichosurus vulpecula) and hare (Lepuseuropeaus) numbers have increased, butrabbit predators such as feral ferrets (Mus-tela furo) and feral cats (Felis catus) havedecreased. However, these changes are notall good news, because New Zealand hasnot only been overrun with rabbits. Thebrushtail possum was introduced from Aus-tralia to provide for an embryonic furindustry in the late nineteenth century.There are now some 60-70 million possumsin New Zealand, which makes them rathermore numerous than sheep, and they occurat far greater densities than they do in theirhome range. The possum is New Zealand’smain mammal pest, causing damage esti-mated at NZ$80-100 million per year, butthe biggest threat is that it is the principalwildlife vector of bovine tuberculosis, andif trade barriers were to be imposed on meatand dairy exports, the economic losseswould escalate. Traditionally, possums inNew Zealand are controlled by the distribu-tion of toxic baits, but economic andenvironmental concerns have pushed theneed for alternative measures to the fore.

Surveys established that the New Zealandpossum population has a very limited para-site fauna compared with its Australiancounterpart, so the possibility of findingand introducing host-specific natural ene-mies was explored. A survey of thepossums in their Australian home rangefound a considerably richer parasite fauna,but most parasites (with the exception ofthe nematode Adelonema trichosuri) arenot specific to the species. Isolated out-breaks of disease in New Zealand,however, have caused high mortality. The

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descriptively-named ‘wobbly possum dis-ease’, caused by a Borna-like virus and anoutbreak of enteritis at another site suggestthat virulent pathogens may exist.Although it may be possible to look fartherafield in both geographic and taxonomicterms, the on-going public and scientificdebate about the introduction of RCD toNew Zealand may make the introduction ofanother pathogen of unknown epidemi-ology fraught with difficulties, and researchhas moved to focus on fertility control.

Inducing Infertility

Research on reducing breeding success isthe control approach seen to have thebrightest prospects at present. Three basictechniques are available:

• surgical sterilization

• hormonal contraception

• immunocontraception

Sterilization of both males and females isgenerally impractical and too expensiveexcept for managing small, easily acces-sible populations. However, there is anextensive government-funded surgical ster-ilization programme in place on KangarooIsland, South Australia, where introducedkoalas (Phascolarctos cinereus) have mul-tiplied to the extent that they haveconsumed their natural food source and arefacing starvation.

Hormonal contraception using steroid sexhormones to disrupt the oestrus cycle is notspecies-specific and is also difficult todeliver to a wild population. In some spe-cies, at least, there may be undesirablebehavioural side-effects to such treatment,as has been demonstrated in African ele-phants. The success is also mitigated in anyanimal group where there is a mating hier-archy: if the behaviour of the dominantsterilized male or female is modified thenthe exercise becomes pointless. On theother hand, targeting the hormonal feed-back loops in the hypothalamus-pituitarysystem that controls gonadal sex hormoneproduction has shown promising results. Ateam led by Henk Bertschinger (Universityof Pretoria) used Deslorin, a synthetic ana-logue of hypothalamic gonadotropinreleasing hormone (GnRH), in hormoneimplants to down-regulate pituitary FSH(follicle stimulating hormone) and LH(luteinizing hormone) release in selectedlarge carnivores such as lions (Pantheraleo), cheetahs (Acinonyx jubatus) andAfrican wild dogs (Lycaon pictus). Themethod was successful in rendering bothmales and females infertile without behav-ioural side-effects, and the infertility wasreversible. However, Linda Munsen foundthat progestogen implants in large cats wereassociated with an increased incidence oftumours of the reproductive tract. Because

the Deslorelin is only available as animplant at the moment, remote delivery isnot possible. Alternative vehicles are beingsought in the USA to allow delivery bymeans of a dart. There has been much otherresearch on using GnRH as a means of con-trolling reproduction. An interestingapproach is the idea of using GnRH orGnRH analogue – toxin complexes to killparticular classes of cells in the pituitary,and so abolish the secretion of reproductivehormones. This is being researched fordogs and cats in the USA and possums inNew Zealand.

Immunocontraception (tricking theimmune system into attacking the repro-ductive process) has a number ofadvantages, including the important char-acteristic of being potentially speciesspecific. The technique is based on devel-oping a vaccine to modify the immuneresponse to key targets in the reproductiveprocess: injected with a protein (antigen),the body produces antibodies to it, and sub-sequently attacks the antigen whenever itappears in the body. Under normal circum-stances, the immune system treats its own(and in the case of females, sperm) repro-ductive proteins as ‘self’ and therefore ‘outof bounds’ as antigenic targets. However, ifan animal were vaccinated with such a pro-tein so that it appears out of context (in thewrong place), it would develop antibodiesto it. The immune system would henceforthtreat such a protein as ‘foreign’ whenever itencountered it, including on sperm or eggsin the reproductive tract, and the animalwould be rendered infertile.

Of possible target sites, the complimentaryproteins in the sperm head and egg (zonapellucida) coating are ideal candidates,partly because they have some degree ofspecies specificity; a physiological adapta-tion that serves to preserve speciesboundaries. This specificity appears to bedependent on oligosaccharide side chainsin the zona pellucida proteins and carbohy-drate binding properties of the spermproteins. Interactions between these arenecessary for a sperm to penetrate an egg.The most commonly used currently in vac-cines, however, are the proteins of the pigzona pellucida (PZP), which are suffi-ciently close to those of horses, deer andelephant, for example, for the PZP vaccineto elicit an immune response against thezona pellucida proteins in these species.Antibodies are formed to PZP injected intothe target animal (because it is differentenough for the target animal not to be ableto recognize it). When the target animalforms an egg which includes the develop-ment of their own zona pellucida proteins,the antibodies will bind to the (target) eggbecause these are sufficiently similar tothose of the pig, hence preventing sperm

from penetrating the target animal’s newlyformed egg.

Any protein that was essential for spermmaturation or progress through either themale or female reproductive tract would beanother opportune target. Vaccines to hor-mones have also been developed. The bestknown of these is a GnRH vaccine, whichwill neutralize GnRH in the vaccinatedanimal, stop FSH and LH release and stopboth males and females from breeding.Many carrier versions of GnRH vaccineshave been studied and the success rate hasbeen good (80-90%). However, use of hor-mones as a means of controlling feral orwild populations of animals, albeit suc-cessful, may be limited owing to the factthat the product could be passed along thefood chain, and this would be likely tooccur also with synthetic or recombinantforms of GnRH.

Courses for Horses

The immunocontraceptive method fordomesticated and feral animals was pio-neered in the USA by Irwin Liu (Universityof California, Davis). First successes usinga vaccine based on PZP were reported in1989 in domestic and semi-captive wildhorses (Equus sp.) in California. Resultsindicated that the vaccine elicited a goodimmune response among the mares vacci-nated, was safe for use in pregnant mares,and did not elicit any short term, adverseside effects. The mares continued to cycleon a normal basis, the contraceptive effectlasted through one breeding season (6-7months) and was reversible: antibody titresto the vaccine began to decrease to lowlevels at the end of this time, and when bredagain the mares became pregnant. Subse-quent studies led by Jay Kirkpatrick (ZooMontana) on Assateague Island poniesdemonstrated that the vaccine could bedelivered remotely. This study found someevidence that repeated vaccination (over 5-6 years) could affect ovarian cyclicity, pos-sibly even causing ovarian senescence.However, the Assateague mares adminis-tered the yearly vaccines were older mares,and these sometimes undergo spontaneousovarian senescence, which renders themares acyclic.

Field implementation of immunocontra-ception in horses in the USA is primarilydirected at wild horses in Nevada, of whichthere are over 20,000. An estimated onethousand mares have been vaccinated inselected locations considered to be over-populated, and most of these were freezebranded or tail docked for subsequent iden-tification. Judging from foal counts at thebeginning of each foaling season and faecalhormone assays during the pregnancyperiods, the vaccination seems to be at least90% effective using the existing delivery

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system. Although the effect on the overallNevada horse population has not beenmeasured, it is clear that in some areas thenumber of foals born from vaccinated herdshas diminished significantly.

Field vaccination campaigns have beenhindered because a course of two inocula-tions (or three for elephants) was needed foreffective contraception. Recently, Liu andhis colleagues have developed a one-inocu-lation vaccine that causes failure ofconception in horses for at least 11 consec-utive months. This relies on a controlledrelease mechanism developed by DougFlanagan (University of Iowa, School ofPharmacy). The research team are nowworking on a one-inoculation vaccine tomaintain the contraceptive effect over twoconsecutive breeding season (20-22months) and this is currently under experi-mental trial. However, although extendingthe period of contraceptive effect will makeimmunocontraception easier to implementand more effective in wild populations,these studies place considerable emphasison demonstrating the reversibility of theprocess, a paramount requirement of aneffective contraceptive agent.

Rutting for Nothing

Immunocontraception in white-tailed deer(Odocoileus virginianus) is not as well doc-umented as in the horse. It has notundergone the same scientific scrutiny,partly because of the difficulties of main-taining deer under controlled conditionsand of obtaining frequent blood samples formeasuring the antibody response withoutstressing the animals. Most experimentswith this species have been carried out onthe USA’s east coast, where the problem ofoverpopulation is more prevalent. There aresome 26 million deer in the USA, and thesehave serious impacts on crops and the envi-ronment (and vehicles!), and are alsovectors for a number of human diseases,including Lyme’s disease, which hasincreased in incidence 25-fold in the last 20years. Amongst a plethora of work on deerin different institutions is research by JohnTurner (Medical College of Ohio), whichhas been followed up in a project led byAllen Rutberg (Tufts University). Theirresults indicated that two doses of PZP vac-cine reduced the fawning rate by 70-90%depending on the delivery method. Datashowed that deer responded to the vaccineand mounted an immune antibody response(producing immunoglobulins). In addition,it has been demonstrated that the vaccinecan be used in pregnant does, and noadverse effects have been found. However,late fawning has been observed among afew vaccinated does, probably because theantibody titres in these animals began to fallbefore the end of the breeding season.Although very few such cases have been

reported, concern has been expressed byanimal advocacy groups, and follow upstudies will investigate whether latefawning is more common in vaccinatedthan unvaccinated does.

Monica Stoops (University of California,Davis) is researching the efficacy of immu-nocontraception in Tule elk (Cervuselaphus nannodes) in California. This spe-cies provides a good example of theproblems that wildlife managers face incontaining mammal populations. The Tuleelk was once nearly extinct in California.By 1872 only five remained, yet now thereare some 3000 in different locations aroundthe state. On Pierce Point in the Point ReyesNational Park the herd that began with tenelk imported in 1978 now numbers some550 head and is overburdening its range.Apart from immunocontraception, possiblesolutions include chemical sterilization,and relocating or shooting ‘surplus’ elk.The elk population may harbour a cattle(Johne's) disease so expansion of its rangeor relocation is unacceptable, and reloca-tion to other reserves would also have anadverse effect on other (invertebrate andplant) species. Public hunting is prohibitedin the area, and killing as a method ofculling faces strong opposition from advo-cacy groups. Introducing more (vertebrate)predators is not considered a viablealternative.

Stoops vaccinated 60 female elk in thePoint Reyes National Park with formula-tions of PZP similar to those used in thewhite-tailed deer studies, and results indi-cated that a contraceptive effect occurred inapproximately 93% of them. Late calvingwas again observed in a minimal number ofinoculated cows, but the numbers were notconsidered significant by the US NationalPark Services, which maintains the herd.

One major criticism aimed at immunocon-traceptive techniques is the suggestion thatmales will continue to fight for the right toserve a female past the end of the rut(breeding season) and thus exhaust them-selves. This is relevant to species such asdeer and elk, where the males fight for theright to service females, although it has notproved a problem in horses. The criticism isbased on the fact that vaccinated femaleswill continue to cycle beyond the end of therut because of their inability to conceive.To date, this has not been shown to haveany impact in the deer and elk speciesstudied. At the end of the rut, the dominantmales tend to stop fighting, and the exist-ence in the herd of still-cycling andreceptive females allows the bachelors toserve females without having to fight forthe right to do so.

Pregnant Paws?

If your closest childhood friend was a teddybear, and you have never had to contendwith bears prowling in your backyard, it ishard to imagine that it might ever be neces-sary to control them. However, in parts ofNorth America bears create a substantialnuisance and danger to the public. Liu’steam began trials in April 2000 by vacci-nating 20 American black bears (Ursusamericanus) with PZP. The female bearshave since been allowed to breed withmales and following hibernation(December until April 2001) the team willdetermine whether the vaccinated and iden-tified female bears have cubs by theirsides… or not!

Jumbo Trial

Field trials of immunocontraception in ele-phants began in 1996 in the KrugerNational Park in South Africa, as part of acollaborative programme between theNational Parks Board and the University ofPretoria in South Africa, and the Universityof Athens, Georgia and ZooMontana in theUSA [see BNI 18(4) (December 1997),104N-105N, ‘Immunocontraception inAfrican elephants’]. Elephants werelocated by helicopter, and non-pregnantfemales were identified by the presence ofa calf less than 1 m high. After anaestheticdarting, non-pregnancy was confirmed byultrasound scan. Elephants were fitted withradio collars, and in a second trial with GPS(global positioning satellite) collars. Theseallowed them to be monitored and for theinitial PZP vaccine to be followed byboosters (at six weeks and six months in afirst trial and two and four weeks in asecond) which were delivered by drop-outdarts from a helicopter. Twelve monthsafter initial vaccination, the elephants wererecaptured and re-scanned. The results(reported in Nature 407, 149) showed thatof ten free-roaming elephants in the secondtrial, only two (20%) became pregnantwithin a year compared to 89% in the con-trol. In addition, a vaccinated elephant inthe first trial gave birth to a healthy calf,indicating that immunization had notadversely affected pregnancy. The immu-nocontraceptive effect was also shown tobe reversible and without any behaviouralside-effects, which gives it major advan-tages over surgical and chemicalcontraception, respectively.

Targeting Pests Down Under

The immunocontraceptive approach is alsobeing developed for three species by thePAC CRC (Pest Animal Control Coopera-tive Research Centre) in Australia: rabbits,foxes (Vulpes vulpes) and mice (Musdomesticus), which are all environmentaland agricultural pests. RCD has lessenedthe rabbit problem, at least in hot, arid

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areas, but it has long been cited as Aus-tralia’s major agricultural pest, and also ascausing (unquantified) damage to nativeflora and fauna. Mice have a serious impacton cereal production in southern andeastern Australia; the unpredictable out-breaks can cause losses worth millions ofdollars, and also social havoc. Foxes causesome losses among lambs, but their mainimpact is on native fauna.

In a collaborative programme involvingLandcare Research, New Zealand and theCooperative Research Centre for the Con-servation and Management of Marsupialsin Australia, which includes units at Mac-quarie University, the University ofNewcastle and Queensland AgriculturalBiotechnology Centre (QABC) in Queens-land and Perth Zoo, the results ofexperimental trials with a vaccine for pos-sums made from whole sperm werepromising, with an 80% reduction in fer-tility in treated females; trials with PZPvaccine gave 75% reduction. Research iscontinuing to improve the efficacy of thisvaccine by isolating the proteins respon-sible for the immune response (and thegenes expressing them), and is looking intothe possibility of using proteins involved inother parts of the reproductive cycle.Experiments with possums in captivityhave shown 70-75% reductions in fertilitywith vaccines based on two zona pellucida(ZP2 and ZP3) proteins. In Australia sim-ilar work is being done on wallabies andkangaroos (Macropus spp.), which in cer-tain areas of the country pose a highlysignificant threat both in competition ofrangelands and crop damage.

So the prospects of a practical tool for somespecies are promising, but how will thisaffect the populations in practice? If low-ering breeding success is to have an impacton population numbers, the birth rate mustbe reduced to match the minimum (density-independent) mortality rate. Modellingstudies suggest that 60-70% of femalesneed to be made infertile to have an impact,but if only males are targeted, almost all ofthem would have to be rendered sterile tohave a sustained population effect. Thismakes male contraception impractical as asole population control tool, but the neces-sary levels of infertility have beenachieved, if only just, in, for example, pos-sums. Improving the ‘hit’ rate of femaleimmunization is therefore a priority, andthis can be partly addressed by improvingthe delivery system. Targeting both malesand females in a population may also bebeneficial.

Safe Delivery

A crucial feature of biocontrol programmesis the development of an effective releasesystem. This is particularly so for immuno-

contraception. In the trial in South Africa,the elephants were darted with anaesthetic,then vaccinated and fitted with trackingcollars. It is not unreasonable to supposethat this method could be simplified (theimmobilizing and tracking phases wouldnot be necessary) for more widespreadapplication in elephants... but not for the30-odd million (female) possums in NewZealand. A rather more automated deliverysystem is needed. One possibility is non-toxic baits (i.e. an oral contraceptive), butan approach currently exciting interest isself-disseminating transmission. The ideawas pioneered in the early 1990s by HughTyndale-Biscoe, who worked for CSIRO(Commonwealth Scientific and IndustrialResearch Organisation) Wildlife andEcology and was at the time the firstDirector of the Vertebrate Biocontrol CRC(which has now evolved into the PestAnimal Control CRC).

The method is based on inserting theantigen into the DNA of a non-virulentviral, bacterial or parasitic vector specific tothe target species. When an animalbecomes infected, the protein gene isexpressed, and the animal’s immunesystem produces antibodies against it, asoutlined above. In Australia, for example,scientists have shown that the vaccineinserted into a non-virulent strain of themyxoma virus can give effective contra-ception in rabbits for up to three months.For captive or isolated populations, a ‘crip-pled’ agent (i.e. one unable to reproduceitself) would be used to infect animals andblock reproduction, but it would not spreadfurther. However, for widespread and inac-cessible populations, an infectious agentcould greatly enhance dissemination of thevaccine. This, though, would have applica-tion in limited instances. In Australia thepossible impact on nontargets would pre-clude its use in marsupial management, butit might be appropriate in New Zealandwhere eradication of the brush-tailedpossum is desirable. But even then, risks ofescape from New Zealand would have to beconsidered. Thus, the risks of using a dis-seminating vector would need carefulevaluation. Henk Bertschinger points outthat although the PZP vaccines are not spe-cies specific, once delivered via a vaccinethey could be inactivated if eaten, so long asthe vaccine is formulated with this in mind.They are thus, in native form, safe withinthe food chain. The danger of virally vec-tored vaccine is that it may not be safewithin the food chain as viruses can and doundergo mutation. He points out that inAfrica, with its vast diversity of species,virally or bacterially vectored DNA vacci-nation would be out of the question; heargues that there is too great a risk that thiswould mutate and affect nontarget species.

Baits are still favoured as a method ofdelivery for mice and foxes. This is in partbecause suitable pathogens for deliveryhave yet to be found for foxes, althoughthere is a candidate for mice, but alsobecause the registration procedure is likelyto be simpler, and the public are expected toaccept baits more easily than an unknownpathogen carrier. In contrast, the epidemi-ology of the rabbit myxoma virus is wellresearched and understood, it is nowendemic in Australia, and there are noclosely related native species. It is also rel-atively easy to incorporate the vaccineprotein gene into it. However, field resultswith naturally occurring myxoma virusstrains have suggested that competitionbetween strains of the virus may affect thefield transmission of a vaccine.

Baiting may remain the method of choice insome cases, and there is interest inincreasing the efficiency of this deliverysystem. All Australian marsupial mammalscurrently targeted are plant feeders, andbaits need to be plant based. MarsupialCRC scientists are investigating the possi-bility of inserting a marsupial antigen intoeasily grown palatable plants, such asmaize or carrots, which would then be for-mulated into baits. Maize is particularlypromising, partly because its geneticmanipulation is fairly tractable and thetechnology well-established, but alsobecause it can be grown as a sterile hybridand it has no close wild relatives inAustralia.

For larger animals, ‘darting’ may remainthe preferred solution over baiting (as itreduces the likelihood of effects on non-target species) and over pathogen-containing vaccines for controlling patchypopulations. In the USA ‘biobullets’, bio-degradable hydroxypropyl cellulose andcalcium carbonate darts, have been devel-oped for delivery of PZP vaccines to white-tailed deer.

Not a Silver Bullet

Reducing breeding success is not expectedto solve all of the mammal problems byitself, but integrated with other biologicaland conventional chemical measures, itwill be a useful tool for population manage-ment, and may allow local, or even area-wide, eradication in some cases. All model-ling in this field has suggested that fertilitycontrol will have to be used in conjunctionwith conventional methods, even if it justmeans a large cull or poisoning programmeto reduce the initial population size fol-lowed by fertility control.

The development of immunocontraceptionis at an early stage, and although trials ofmarsupial vaccines, for instance, may beginwithin the next five years, it may be 10-15years before vaccines and delivery systems

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are perfected for all of the current targetspecies. There are many hurdles still to beovercome, not least of which is dealingwith the (differing) risks involved in thenew techniques, and in the mode ofdelivery. For bait delivery, species specifi-city and biodegradability are key, while fora vaccine vector, the specificity of the vac-cine and the specificity of the mode oftransmission are both critical. If the agentof transmission is a genetically modified,albeit non virulent, pathogen, then publicand scientific concerns relating to therelease of genetically modified organismsinto the environment need to be addressed.So do public worries about spreading whatmight sound suspiciously like a disease –worries familiar to classical biological con-trol practitioners working with alienpathogens.

Given the antipathy that can be raised, it iswise to involve all stakeholders in decisionmaking on wildlife problems, and wherethis has been done it has had very beneficialconsequences. Irwin Liu suggests that themost significant contribution of imunocon-traception so far in the USA has been inreducing the hostility between governmentagencies (who have jurisdiction over mostof the wild animal populations) and advo-cacy groups. Developments in fertilitycontrol could lead to effective methods forhumane management of mammal popula-tions, with minimal cost and humanintervention, that are acceptable to mostparties.

Contact: Henk Bertschinger,Department of Reproduction,University of Pretoria, Private Bag X04,Onderstepoort 0110,Republic of South AfricaEmail: henkbert@op.up.ac.zaFax: +27 12 529 8314

Phil Cowan, Marsupial CRC,

Landcare Research, Private Bag 11052,

Palmerston North, New Zealand

[possum fertility control, New Zealand]

Email: cowanp@landcare.cri.nz

Fax: +64 6 355 9230

David Kay,

Department of Biological Sciences,

The University of Newcastle,

Callaghan, NSW 2308, Australia

[marsupial fertility control, Australia]

Email bidjk@alinga.newcastle.edu.au

Fax: +61 249 216923

Irwin Liu, Department of Population

Health and Reproduction,

Room 1114, Tupper Hall,

School of Veterinary Medicine,

University of California, Davis,

CA 95616, USA

Email: ikliu@ucdavis.edu

Fax: +1 530 752 4278

John Parkes, Landcare Research,

PO Box 69, Lincoln, New Zealand

[rabbit RHD, New Zealand]

Email: Parkesj@landcare.cri.nz

Fax: +64 3 325 2418

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Metarhizium: Changing Locust Control

We have many times covered progress inthe development of biopesticides based onMetarhizium anisopliae var. acridum forlocust control. Now there are formulationsready for use, and at a time when locust out-breaks in many parts of the world arehitting the headlines. However, it is notonly the ‘green’ credentials of the biopesti-cides that make them an exciting new tool,but the promise they bring of new strategiesfor controlling this most infamous of insectpests. The biopesticides have a slow knock-down rate (up to 10 days) compared to con-ventional insecticides, but field trials haveshown them to have a more persistenteffect, and this makes them ideal for use inbreeding areas. In addition, their environ-mental safety means that they can be usedin conservation areas where locusts werepreviously safe from the sprayers.

Locusts Face Operation

The biopesticide Green Guard™ developedby CSIRO (Commonwealth Scientific andIndustrial Research Organisation) andmanufactured by Seed Grain and Biotech-nology (SGB), Albury is to be usedoperationally this year as Australia faces itslargest-ever plague of locusts. According tothe Australian Plague Locust Commission(APLC), for the first time in living memorylocusts threaten agricultural production onboth sides of the continent in the same year.Western Australia is facing the largestplague ever, threatening its wheat belt andother agricultural areas. South Australia isfacing the largest since 1955, and NewSouth Wales and Victoria the largest in tenyears. Graeme Hamilton, head of APLC,says that an intensive control effort will beneeded to avert major crop and pasturedamage.

Months of planning a defence strategy withstate agricultural departments and farmergroups will be put to the test. A key elementof this will be the Metarhizium-basedGreen Guard™, which has been given aspecial permit by the National RegistrationAuthority for Agricultural and VeterinaryChemicals (NRA) to be used in widespreadoperational trials. It is applied under thedirection of APLC as an aerial spray of dryspores suspended in oil, with locustsinfected either by direct contact or bypicking up spores from vegetation. Thespores penetrate the body and kill the

locusts in the second week of infection.This is a major boost in the APLC’sarmoury, and a surprise for the locusts, as itenables the commission to spray in conser-vation areas, on organic farms and insensitive environmental places such as wet-lands and river banks where chemicalpesticides cannot be used. The biopesticide,which is based on a native Metarhiziumstrain originally collected from the spur-throated locust (Austracris guttulosa) willalso be used in trials in Western Australia(WA) for the first time by the WA Agricul-ture Protection Board. Green Guard™ isnot available to farmers and landholders,however, as not all the data required forregistration by the NRA has been compiled.CSIRO anticipates that this registration willtake place within the next twelve months.The operational trials permitted this yearwill be an important element in the registra-tion process.

Head of CSIRO Entomology, Jim Cullen isdelighted with that the promise shown byMetarhizium is bearing fruit in such animportant application as locust control.Trials last year showed high locust mor-tality at one fifth of the anticipated dose,and at this low dose the cost of using thebiopesticide is competitive in price withchemical insecticides.

Contact: Richard Milner,

CSIRO Entomology, GPO Box 1700,

Canberra, ACT 2601, Australia

Email: richardm@ento.csiro.au

Fax: +61 2 6246 4042

Buying into Biopesticides

Meanwhile in Niger, stakeholders involvedin the development and deployment ofGreen Muscle™ are celebrating the firstcommercial release of the biopesticide inwhat is believed to be the largest aerialspraying of a biopesticide ever conductedin Africa. Early reports indicate that thebiopesticide provides complete control forup to three times longer than chemicalinsecticides currently used, making it lessexpensive and environmentally safer forfarmers.

The commercial release of GreenMuscle™, conducted in August 2000, tar-geted a 2000 ha area in Tahoua Province.Tahoua, an area of fertile agricultural val-leys south of the Sahara desert, wasdevastated by locusts four times between1986 and 1989 and again in 1992-93. Thegovernment of Niger, which is the firstAfrican government to integrate the biopes-ticide into its pest control programme,plans to introduce biopesticides to 300,000ha of agricultural land currently treatedwith chemicals. The per unit cost of usingthe biopesticide (less than US$10/ha) isapproximately the same as conventionalpesticides, but its overall usage cost is

94N BiocontrolNews and Information 2000 Vol. 21 No. 4

about one-third less because the fungusrequires only one application per season.

The fungus strain currently used by scien-tists is indigenous to Africa, but strainsfrom various origins can be used to makelocalized formulations for different regions(as indeed CSIRO has done). Developmentof Green Muscle™ was an inter-discipli-nary effort, involving identification of anappropriate strain of the fungus, and devel-opment of methods for its mass productionand application. The isolate used for GreenMuscle™ was selected from more than 160strains of fungi and other locust pathogens.Mass produced fungal spores are added toan oil-based carrier for spraying, a processapproved by the Food and AgricultureOrganization of the UN (FAO) in 1997.Biological Control Products of Durban,South Africa was the first company toreceive a license to produce GreenMuscle™ and negotiations are currentlyunderway with other manufacturers in theprivate sector.

Jürgen Langewald (International Instituteof Tropical Agriculture, IITA), projectleader of LUBILOSA (LUtte BIologiquecontre les LOcustes et les Sauteriaux)which developed Green Muscle™, pointsout that because of the immense size andrange of locust swarms, there is little thatindividual farmers can do when locustsstrike, so it is up to governments and inter-national organizations to take the lead. Heis enthusiastic about the potential of GreenMuscle™ for controlling locusts in theirbreeding grounds. Areas around the RedSea could be treated each year with thebiopesticide to catch young locusts beforethey are mature enough to fly and become athreat to farmers’ fields. According toLangewald, the cost of treating these areaswould amount to US$15 million annually, afraction of the $500 million that might beneeded for all-out chemical spraying afterthe locusts have swarmed. He points outthat while it is easier to raise money after acrisis has occurred, a programme based onprevention through biological control willbetter serve both people and the environ-ment. According to the government ofLuxembourg, the major funder of Niger’sgrasshopper and locust control pro-grammes for many years, the August sprayshave already helped to shift the thinking ofNiger’s pest control establishment – adirect result of the LUBILOSAprogramme.

Contact: Jürgen Langewald, IITA,B.P. 08-0932, Cotonou, BeninEmail: j.langewald@cgiar.org

Read All About It!

For more about the history of theLUBILOSA story, a new publication*traces the development and commercializa-

tion of biologically based technologies forsustainable locust control. A public-privatepartnership involved a group of govern-mental aid agencies who provided US$13million for an international inter-institu-tional research and developmentprogramme into the problem of locust con-trol for the developing world. Theprogramme showed that public-privatepartnerships can work, and that public andprivate perceptions about intellectual prop-erty rights can be reconciled. The result isGreen Muscle™.

*Dent, D (2000) Intellectual propertyrights, partnerships and the LUBILOSAStory. Egham, UK; CABI Bioscience.Contact: David Dent, CABI Bioscience UKCentre (Egham), Bakeham Lane, Egham,Surrey, TW20 9TY, UKEmail: d.dent@cabi.orgFax: +44 1491 829100

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Dr M. A. Ghani: His Contributions to Biological Control

Over a span of almost fifty years DrMohammad Abdul Ghani, until his retire-ment in 1980, led a distinguished career inentomology and biological control.

Born on 10 June 1915 at Ludhiana(Punjab), India he completed his early edu-cation at Arya High School beforeattending Punjab Agricultural College,Lyallpur where he obtained both his B.Sc.and M.Sc. degrees, graduating in 1945 atthe top of his class. On the basis of his aca-demic excellence he was awarded ascholarship by the Government of Punjabto pursue graduate studies in the USA. Hecompleted his Ph.D. at the University ofMassachusetts in Amherst in 1950.

His entomological career started in 1934when he was appointed Research Assistantin the Entomology Section of the PunjabAgricultural College and Research Insti-tute, Lyallpur (now the University ofAgriculture, Faisalabad). On his returnfrom the USA he rejoined the EntomologyDepartment of the University of Punjab andwas promoted to Associate Professor, Uni-versity of Agriculture in April 1955. InJune 1955 he was appointed Plant Protec-tion Entomologist, Plant ProtectionDepartment, Government of Pakistan. Twoyears later in 1957 he joined the Common-wealth Institute of Biological Control(CIBC) as Entomologist-in-Charge of thenewly formed Pakistan Station atRawalpindi, a position he held until hisretirement in 1980.

From its inception Dr Ghani was deeplyinvolved in the planning and constructionof the CIBC Pakistan Station which was

funded largely by Colombo Plan Fundsprovided by Canada. A tireless worker andexcellent organizer, the project load of thestation grew rapidly requiring the develop-ment of a chain of up to eight substations toservice a broad array of biological controland integrated pest management (IPM)activities. In addition to financial assistancefrom Canada, the Pakistan Government andthe Commonwealth Agricultural Bureaux,United States PL480 projects proved amajor source of funding during most of theperiod that Dr Ghani spent with CIBC.Once the Pakistan Station became fullyfunctional between 12 and 27 majorprojects, many of them of several yearsduration, were being carried out at any onetime. During the 23 years he served CIBC,he undertook personally, or directed, morethan one hundred projects in biologicalcontrol and IPM. Investigations wereundertaken for, and/or natural enemieswere shipped to, more than 30 countries.These led to the establishment of a numberof natural enemies and to partial or com-plete biological control of the target insector weed pest. The most outstanding of theseresulted from the introduction from Paki-stan to New Zealand of the braconidApanteles (= Cotesia) ruficrus for the con-trol of the cosmopolitan armywormMythimna separata. Establishment of theparasite and its impact on the host quicklyresulted in a dramatic reduction of pesticideuse and increase in crop yields. The esti-mated annual monetary benefits range fromNZ$4.5 million to NZ$10 million1.

To develop and sustain this heavy work-load Dr Ghani recruited a team of youngPakistani entomologists and other scien-tists: several of these, under his guidance,completed advanced degrees whileworking at the Station and later acceptedpositions of national or international prom-inence in biological control and IPM. DrGhani also acted as external examiner for anumber of M.Sc. and Ph.D. students atthree universities in Pakistan, and sat onvarious university committees. He activelypromoted and encouraged universitycourses in biological control and IPM andpublished more than 80 papers in nationaland international journals.

In addition to his duties at the Station DrGhani travelled abroad extensively and vis-ited most of the continents in connectionwith professional activities, at times underarduous conditions. During 1961 he spenttwo months in Indonesia collecting sugar-cane borer parasites for Mauritius. Inaddition to enduring great personal discom-fort he was forced to part with his wristwatch and several other personal items asinducement to permit him to continue hisinvestigations and to ensure that thenumerous shipments of parasites to Mauri-

News 95N

tius, Trinidad and India were dispatchedexpeditiously.

In recognition of his services and dedica-tion to his profession several honours wereconferred on Dr Ghani. These included theGold Medal in Biological Sciences for1970 by the Pakistan Academy of Sciences,Gold Medal by the US Department of Agri-culture for excellence of research on PL-480 projects in 1985, and ‘Tamgha-e-Quaid-I-Azam’ by the Government ofPakistan in 1965. He was a member andfellow of several learned societiesincluding the Pakistan Academy of Sci-ences and the Royal Entomological Societyof London.

Always a very modest and courteous manDr Ghani, after his retirement from CIBC in1980, lived quietly with his family in Fais-alabad, and later during a protracted illnessin Islamabad where he died on 6 April2000. Dr Ghani leaves behind his wife,three sons, one daughter and tengrandchildren.

1Hill, M.G.; Allan, D.J. (1989) Mythimnaseparata (Walker), cosmopolitan army-worm (Lepidoptera: Noctuidae). In:Cameron, P.J.; Hill, R.L; Bain, J.; Thomas,W.P. (eds) A review of biological controlof invertebrate pests and weeds in NewZealand 1874-1987. CIBC Technical Com-munication No. 10. Wallingford, UK; CABInternational, 424 pp.

By: F. D. Bennett* and A. I. Mohyuddin***Crofton, Baldhoon Road,Laxey IM4 7NA, Isle of Man**Integrated Pest ManagementConsultants, 16 Khayaban-e-Johar, I-8/3,Islamabad, Pakistan

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Dieter Schroeder Bows Out

After more than 40 years in the service ofbiological control, Dieter Schroeder retiredin September 2000. For almost all of thisperiod he was based at the CABI Bio-science Centre Switzerland (formerly theEuropean Station of the CommonwealthInstitute of Biological Control – CIBC,then the International Institute of Biolog-ical Control – IIBC). He was CentreDirector for the last four years, a periodespecially noteworthy for the constructionof an extension to the centre building thatincreased the accommodation by 50%.Matthew Cock, formerly IIBC DeputyDirector of Operations and CABI Bio-science Weed Biological ControlProgramme Leader takes over as CentreDirector of the Switzerland Centre in Delé-mont, with its active and committed staffand strong research programme.

Dieter was born in Germany in 1935 andpassed his youth in what was called EastGermany after 1945. His wish to studybiology could not be realised in the circum-stances, but since he was trained as alumberjack he was ordered to study for-estry. Three months before his finalexaminations he was forced to leave EastGermany and finished his studies in Göt-tingen, West Germany. Instead ofbecoming a forest district officer, heaccepted an offer to become junior ento-mologist at the European Station of CIBC,working on biological control of forestpests, such as larch sawfly, pine sawflies,balsam woolly aphid and pine shoot moth.The latter species became the subject of hisPhD thesis in 1962. In 1969 he joinedHelmut Zwölfer in his work on biologicalcontrol of invasive weeds, includingamongst others leafy spurge, thistles and St.John’s wort, and he took over the Delémontweed section in 1973, when HelmutZwölfer left.

Before concentrating on weed biocontrol,he spent a year in Ghana, running the CIBCGhana Sub-station, and working on pests ofcorn, rice, cocoa, and water weeds. Fol-lowing his return to Switzerland in late1970, he worked in close cooperation withPeter Harris in Canada, mainly on knap-weeds and leafy spurge, but also on anumber of other species, such as mullein,bladder campion, sow-thistle, toadflax anddandelion. Over the past twenty years, bio-logical weed biocontrol developed into amajor component of the work of the centrein Delémont with six research scientists anda varying number of Diploma and PhD stu-dents. Dieter has written or co-authoredwell over 50 publications that have greatlystimulated ecological thinking in biologicalcontrol.

Quite early on Dieter established closecooperation with the USDA-ARS (USDepartment of Agriculture – AgriculturalResearch Service) and the AustralianCSIRO (Commonwealth Scientific andIndustrial Research Organization) Euro-pean weed biocontrol laboratories, andinitiated with Paul Dunn annual meetingsof the three groups to exchange informa-tion, and to avoid duplication of work.Supported by Peter Harris, Dieter put mucheffort into encouraging Canadian and USscientists and sponsors to join forces andform consortia to enhance support andprogress in biological control of invasiveweeds. There are now several such con-sortia coordinating the biological controlprogramme against different weed targets.In addition to his Europe-based weed work,Dieter travelled the world, participating ininternational training courses in Trinidad,India, Pakistan, and Kenya, and acted as a

consultant in North America, Africa, Chileand the Solomon Islands.

Dieter’s contribution to weed biologicalcontrol was recognised publicly by profes-sional colleagues last year when he was anhonouree of the Xth International Sympo-sium on Weed Biological Control atBozeman, along with Peter Harris andLloyd Andres. This year his retirement wasmarked more informally at a party held atthe CABI Bioscience Switzerland Centre inAugust. The staff and students of theCentre, together with collaborators andformer staff from Switzerland, Germany,Canada and the USDA EBCL (EuropeanBiological Control Laboratory) Montpel-lier, marked the occasion with one of theCentre’s traditional barbecues, and thepresentation of gifts and mementos,including a book of personal memories,stories and pictures sent by more than 50colleagues from around the World… andthe Centre’s last ash tray! Proceedings werefurther enlivened with the first public per-formance of ‘Dieter’s Song’ (set to the tuneof ‘Those Were the Days’), a display ofsalsa dancing by students of the Centre andan exhibition of juggling by a distinguishedguest whilst he gave a commentary in threelanguages. Dieter will be remembered bythose who worked with him for his enthu-siasm, strong opinions, and certainly hishumour and many jokes and stories. We allwish Dieter a long and fulfilling retirement,which, judging by his plans, will be no lessbusy than his career.

By: Matthew Cock and André Gassmann(CABI Bioscience Centre Switzerland)and Heinz Müller-Shärer (University ofFribourg)

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New Committee for IOBC

IOBC, the International Organisation forBiological Control of Noxious Animals andPlants, has announced its new global exec-utive committee for 2000-2004. Thepresident is Lester E. Ehler (University ofCalifornia at Davis, USA), and Joop vanLenteren (University of Wageningen,Netherlands) and Stephan Pruszynski(Plant Protection Institute, Poznan, Poland)are vice-presidents. André Gassmann(CABI Bioscience Centre Switzerland)becomes secretary-general, and FritzPolesny (Institute for Phytomedicine,Vienna, Austria) is treasurer.

Contact: Mireille Montes de Oca,

IOBC Permanent Secretariat, Agropolis,

Avenue Agropolis,

34394 Montpellier Cedex 5, France

Email: IOBC@agropolis.fr

Fax: +33 4 67 04 75 99

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96N BiocontrolNews and Information 2000 Vol. 21 No. 4

IPM Systems

This section covers integrated pest man-agement (IPM) including biologicalcontrol, and techniques that are compatiblewith the use of biological control or mini-mize negative impact on natural enemies.

Rational Pesticide Use: an Alternative Escape from the Treadmill?

IPM is a strategy that aims to optimize allavailable techniques in order to maintainpest populations at levels below thosecausing economic injury. The conceptsbehind IPM have evolved since their begin-nings in the late 1950s. It is generallyagreed that one of the primary objectives isreduced reliance on (especially toxic,broad-spectrum) pesticides and somebelieve that IPM may (or should) result inreduction or removal of chemical pesticideuse. In practice, however, the pesticideindustry has remained a profitable(although maturing) business (Figure 1).

This indicates that many farmers continueto believe that pesticides are necessary toprevent significant losses in many crops(the largest market), besides which, insecti-cides continue to be used for control ofdisease vectors and nuisance pests. Here, Iexamine some of the reasons for the con-tinued prevalence of pesticides in pestmanagement, and suggest how a more rea-soned approach, which accepts the value ofpesticides but concentrates on deliveringthe active ingredients (a.i.s) more effec-tively, can make a real contribution topesticide reduction.

Changes in pesticide use are not as easy toquantify as it might seem. During the finaltwo decades of the 20th century, the totalvalue of pesticide sales increased some 2.5times. This statistic can be misleadingbecause it does not take factors such asinflation into consideration, but averagetrade weighted growth has been some 1.6%annually. Figures for tonnes of pesticideproduced are hardly more useful, since

modern pesticides are used at substantiallylower rates of application. It would beuseful to express sales in terms of hectaredosages, but such data are available onlyvery rarely (a notable exception being inDenmark, see: <http://www.inet.uni2.dk/~iaotb/top20.htm>). Figure 1 reveals someother significant trends including (a) anincrease in the importance of herbicides(mostly at the expense of insecticides) and(b) the present relative unimportance ofgenetically modified crops (in contrast totheir news-worthiness). Figure 2 showshow the regional distribution of pesticidesales has varied over last 20 years.Although Europe and North America con-tinue to account for the largest portion ofthe market (some 56% combined), therehas been nearly a 10% increase in themarket share to 36% for Asia and SouthAmerica (partly in place of easternEurope), and pesticide use patterns in theseregions therefore deserve special attention.

Figure 1. Worldwide pesticide (crop protection) markets in the final two decades of the 20th century (data compiled from British CropProtection Association Annual Reports).

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Figure 2. Regional trends in pesticide use (data source as Figure 1).

The term rational pesticide use (RPU) wascoined in the title of a book by Brent &Atkin in 19871; it can be defined as afocused sub-set of IPM, which attempts tomitigate the adverse effects of pesticide useby improvements in the selectivity of theproducts themselves and the precision oftheir application in both space and time.The benefits are maximized with a combi-nation of all three, and the potential benefitsinclude: reduction of costs (for both pesti-cides and labour), improved safety(especially with insecticides) and reducedenvironmental impact (through more effi-cient use of sprays and the use of specificagents).

On a world-wide scale, farmers are likely tobe most interested in cost savings, but thiswill be especially important in the poorestcommunities. Developing countries pres-ently account for approximately 25% ofglobal agricultural sales values and thisproportion is projected to rise. However,not only do agricultural inputs contribute tothe debt cycle, but with limited access toprotective clothing and medical facilities,cases of pesticide poisoning are morecommon in developing countries, and havea greater impact on poorer farmers.

Concepts similar to RPU have been pro-moted elsewhere: all attempt to achievesustainable agriculture, with a low environ-mental impact, through a combination ofappropriate technologies, but not neces-sarily excluding the use of pesticides.Examples include: lutte raisonée (super-vized control) promoted by the FARREproject in France; ‘green agriculture’ pro-moted by the Chinese Academy of

Agricultural Sciences (together with ‘whiteagriculture’, that focuses on the use ofmicrobial agents); and ‘clean production’in Vietnam (where management of pesti-cides is combined with more careful use ofhuman waste as a fertilizer).

It is beyond the scope of this article toreview the many facets of RPU, but it high-lights some of the ways in which it canbenefit IPM, concentrating in particular onthe potential of controlled droplet applica-tion (CDA).

Slow Growth of Specifics

There has been a significant trend towardsthe development of molecules and formula-tions with lower mammalian toxicity by themajor agrochemical companies over thelast 30 years. However, with huge develop-ment costs, the companies have been underpressure to develop pesticides which have abroad spectrum and thus a wide market, forexample neo-nicotinoids and pyrethroids.More specific compounds (even aphicides)by definition occupy smaller proportions ofthe pesticide market and therefore promisea smaller potential return on researchinvestment. In addition, toxic chemicals(especially organophosphorus compoundssuch as methamidaphos and monocroto-phos) are still widely manufactured andmarketed, and alarmingly are still availableto unprotected smallholders in some devel-oping countries. More specific compoundsare available (e.g. insect growth regulators,fermentation products such as spinosad,and biopesticides) but they tend only to fill‘niches’ in the pesticide market. Althoughthe need for more specific insecticides isoften identified in farmer field schools and

by scientists, commercial pressures meanthat this does not translate easily to themarket place.

Paradoxically therefore, one of the costs ofheightened regulatory pressure has been anincreased incentive to develop broad-spec-trum products that have a large marketvalue, thus possibly increasing the impactof pesticides on nontarget organisms andthe environment. The use of broad-spec-trum molecules is known to aggravateproblems such as pesticide-induced resur-gence of relatively unimportant insects andmites. One of best-known examples of thisis brown planthopper (Nilaparvata lugens)in tropical rice, which flares-up almost pre-dictably after applications of manypyrethroids. With appropriate cultivation ofthis crop, it is most straightforward to dis-courage insecticide use all together,although migratory pests may remain aproblem. However, the use of herbicides(for directly seeded rice) and fungicides(against diseases such as sheath blight) isincreasing in some countries, and RPU maybe able to provide the more complex solu-tions needed for effective rice protection insuch situations.

Between Two Camps

Although good IPM practice comprises thebest combination of techniques to managepests, opinions about the emphasis placedon the various components have becomepolarized over the last 30 years. Mostauthorities agree that successful pest man-agement requires a holistic approach thatincludes cultivation of the crop itself; thussome sections in the Food and AgricultureOrganization of the UN (FAO) and other

98N BiocontrolNews and Information 2000 Vol. 21 No. 4

workers with a background in biologicalcontrol refer to ‘integrated production andpest management’ (IPPM). On the otherhand, the Global Crop Protection Forum,representing the major companies wishingto develop both pesticides and geneticallymodified crops, promotes the term ‘inte-grated crop management’ (ICM).Unfortunately the protagonists of the twoapproaches rarely talk to one another, eventhough there are many similarities betweenthe concepts (their main disagreements areoften over essentially socio-economicmatters).

Faced with the sustained importance of pes-ticides, and the absence of specificcompounds, RPU provides a means of min-imizing use and impact, and this fills aniche in IPM left by pesticide-excludingapproaches, yet always attempts to mini-mize their impact. Scientists, practitionersand policy makers involved in IPM havetended to view any activity associated withpesticides as belonging to the pesticidecompanies (and preferably to be avoided).In turn the chemical companies (whichoften provide farmers with most of theirinformation on products) are unlikely todevelop or promote techniques that reducepesticide use (and hence sales). The resultis a lack of information and technologicaldevelopment for improving the selectionand use of pesticides in a way that will leadto real reductions in use.

Applying Less More Precisely

It is rarely appreciated just how inefficientexisting application practices are. In 1977,Graham Bryce pointed out that most con-ventional insecticide applications as foliarsprays were <0.05% efficient, although(exceptionally) this might reach 6% effi-ciency for aerial sprays to locust swarms,and herbicide sprays on grass weeds mightreach 30% efficiency. Thus, even in thebest case, 70% of the pesticide is wasted.Improved application techniques receivedmuch attention and extensive research inthe 1970s and 80s, but then went out offavour, partly when the commercial poten-tial of genetically modified crops becameapparent. With the increased use of herbi-cides, application research in the 1990soften focused on control of spray drift (notnecessarily accompanied by gains in effi-ciency: see below). Most recently, theconcept of ‘precision spraying’ hasreceived attention, which is linked tosophisticated crop monitoring techniquescontrolled by global positioning systems,and applications are targeted to patches ofpests (usually weeds). However, precisionspraying has been developed for Europeanand North American conditions and essen-tially relies on switching conventionalatomizers on and off; it does not necessarilyaddress the fundamental inefficiencies

resulting from the random nature of liquidbreak-up by hydraulic pressure.

The concept of controlled droplet applica-tion (CDA) is perhaps the ultimate inprecision spraying, but it has been disap-pointingly limited to niche markets. Itattempts to maximize dose transfer to agiven pest target by the creation of appro-priately sized, uniform pesticidal droplets(within practical engineering limits). Anumber of studies have shown smaller(<150µm) droplets to be more effective forcontrol of arthropod pests and plant dis-eases than larger ones. Optimization ofherbicide use involves a compromisebetween minimizing drift (by minimizingthe volume of spray with droplet sizes of<100µm) but also ensuring that droplets arenot so large that they bounce off foliage (aneffect that may start to occur if they are>200µm). For a given biological target it isusually possible to estimate the approxi-mate limits of an optimum size band forspray droplets, but more research with indi-vidual cases is always desirable. Inaddition, by targeting sprays better andreducing their number, it may be possible toprolong the life of a.i.s by delaying thedevelopment of pest resistance.

CDA uses minimal quantities of a pesticideto maximum effect by improving timingand spatial application, with the additionalbenefits of reducing off-target contamina-tion and improving work rates. By creatingnarrow droplet spectra, ultra-low volume(ULV) or very low volume (VLV) applica-tion rates can achieve similar (sometimesbetter) biological results than conventional(hydraulic atomizer) application. Perhapsone of the greatest practical advantages ofthese low volume techniques involves theircapacity to improve work rates; forexample, one hectare of cotton might takemore than 11 hours to spray at 200 litres/ha(with a conventional knapsack sprayer), butonly 4 hours at 10 litres/ha (VLV) or onehour at one litre/ha (ULV). Such improve-ments in work rate not only reduce labourcosts, but also improve timeliness of appli-cation in response to monitoringtechniques; thus CDA is a very goodexample of RPU technology.

Early CDA initiatives had only limited suc-cess, probably due to a combination ofunreliable equipment, insufficient promo-tion and a perceived need for specialformulations. The cause was not helpedwhen the inventor of modern rotary atom-izers, Edward Bals, suggested in 1969 thatbesides ULV rates of application, CDAmight achieve ‘ultra-low dosages’. This ideawas obviously an anathema to many chem-ical companies since it could threatenproduct sales. However early in the 1980s,ICI (now Zeneca, shortly to become Syn-genta) recognised, with the development

‘Electrodyn’ technology, that profitabilitywas not necessarily linked to tonnes of a.i.sold. It recognised that added value might beachieved by incorporating the product in aproprietary delivery system for smallholderfarmers. Electrical forces were used to breakup the oil-based formulation into very small,very evenly-sized droplets, then to carry anddistribute them onto the plant surface. Bycombining the bottle, formulation andnozzle in a closed, disposable system (the‘Bozzle’), operator exposure and applicationerrors could dramatically be reduced byeliminating the mixing and measuring stagesand simplifying calibration.

Although technically brilliant, electrostaticspraying in general has failed to make acommercial impact. In the case of the Elec-trodyn, farmers in some areas wereunwilling to commit themselves to theproducts of just one company, and there hasbeen increased regulatory pressure againstthe solvents used in formulations (a criticalcomponent in the ‘Bozzle’ system). How-ever the rotary atomizer companies survive,and many of the technical problems thatconstrained widespread adoption of CDAin the early days have now been resolved.With the current heightened awareness ofenvironmental, social and toxicologicalissues associated with pesticides there isperhaps an opportunity to ‘rediscover’some of these latent technologies. Providedrelatively non hazardous a.i.s are used,CDA spraying, together with other RPUtechniques such as banding, baiting, spe-cific granule placement and weed wipingmight even ameliorate the currently poorimage of pesticides. However, in many cir-cles drift is seen as one of the majorproblems that pesticide applicationresearch has to address.

Drifting Off-Course

Recent changes in policy and practice(especially in Europe and North America)have focused on reduction of spray drift (anissue that has always been important withherbicides). The most common solution hasbeen to develop nozzles that increasedroplet size spectra, although this shifttakes spray droplet size out of the rangedemonstrated to be effective for pesticideapplication. In 1974 Himel distinguishedbetween ‘exodrift’ (transfer of spray out ofthe target area) and ‘endodrift’, where thedroplets fall into the target area but the a.i.does not reach the biological target. Endo-drift is volumetrically more significant andmay therefore cause greater ecological con-tamination (e.g. where chemical pesticidespollute ground water). Unfortunately, thepolicy and regulatory changes thatencourage the use of larger droplet sizes inordinary spray nozzles risk reducing exo-drift at the expense of an increase inendodrift. With spray application, it is

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important to focus on maximizing pesticidedelivery to the target, rather than just mini-mizing drift. Concepts such as controlleddrift spraying with narrow droplet sizespectra are often critical to the success oflow volume application and can achieveefficient dose transfer to the biologicaltarget.

Figure 3 illustrates this by showing thedroplet size spectra from four different noz-zles, juxtaposed to bands indicating theprobable optimum size ranges from a bio-logical point of view. Note also that there isa cubic relationship between a droplet’sdiameter (its ‘perceived’ size) and its

volume (proportional to dose). Large drop-lets that bounce off leaves may still beappropriate for pre-emergence herbicides,but are wasteful in most other circum-stances. The same volume of pesticidebroken up into smaller droplets could makeup a large number of effective doses whereplants or insects are the target. The 110-03flat fan nozzle, often fitted to tractor boomsprayers, is very widely used in westernagriculture. At 300 kPa pressure it pro-duces a ‘medium spray’ which includesdroplet sizes ranging from those that are toosmall even to be appropriate for fungicides,to ‘drops’ that are >500 µm. In an attempt toreduce the <100 µm proportion, the same

manufacturer produces a ‘low drift’ nozzle

with an equivalent output; the proportion

<100 µm has been halved to <4%, but this

nozzle also produces a wide spectrum of

droplet sizes, and the median diameter has

been shifted from approximately 150 µm to

>300 µm. Compare these spectra with two

rotary nozzles: the Ulva+ set for application

of water-based insecticide formulations

and the ‘Herbi’ designed for spraying her-

bicides. Using the optimum droplet size

criteria, appropriately set rotary atomizers

can increase the volume of output in these

ranges from <40% to approximately 80%.

Figure 3. Droplet size spectra of output from four atomizers spraying water + 0.1% surfactant (Agral 90) measured by a 'Malvern 2600'particle size analyser.

100N BiocontrolNews and Information 2000 Vol. 21 No. 4

Rotary atomization is not appropriate for allpest control situations, and hydraulic nozzlesare by far the most important means ofspraying pesticides. However much could bedone to reduce wastage (and operatorhazard) with conventional equipment, bybetter choice and maintenance of equipment.It is interesting to speculate how much of themoney spent on pesticides shown in Figure1could be saved by widespread adoption ofimproved techniques. If efficiency were tobe doubled (eminently feasible from a tech-nical point of view) then RPU could savemankind some US$15 billion annually. Per-haps there is indeed little incentive forpesticide manufacturers to promote improvedapplication techniques.

Getting the Bugs Out

There has been much recent interest in bio-logical pesticides, and the development ofdelivery systems for microbial agents pro-vides an excellent example of RPU.Biopesticides are among the most specificagents available to the farmer; however,their share in the total pesticide marketremains below 1%, and there have oftenbeen technical, logistic and commercial dif-ficulties in providing the biologicalproducts that have been identified as mostappropriate for IPM in some crops.Although widely liked by both ICM andIPPM protagonists, biopesticides willremain primarily subjects for discussion,unless the technical, commercial and con-ceptual issues can be resolved, so that moreproducts appear on shelves and farmerswant to use them.

Amongst perceived constraints are narrowtarget spectra, poor performance relative tocost, and inconsistent product quality, but amajor problem with current use is the poorstandard of application to crops, allied witha belief that horizontal transmission miti-gates the need for good delivery systems.However, there are studies showing that, aswith chemical pesticides, droplet size andcoverage affects the efficacy of agents suchas Bacillus thuringiensis. Unlike manychemical formulations, biopesticides arenecessarily suspensions (as opposed tosolutions) and the concept of dose transferto the target pest in the form of particlesmust underlie the development of effectivedelivery. By monitoring efficacy overweeks (rather than days), some biopesti-cides are substantially more efficaciousthan their chemical rivals.

This can be illustrated by results gainedwith the international LUBILOSA Pro-gramme.LUtte BIologique contre lesLOcustes et les Sauteriaux is a collabora-tive, multi-disciplinary research anddevelopment programme funded by theGovernments of Canada (CIDA), the Neth-erlands (DGIS), Switzerland (SDC) and the

UK (DfID). It was set up to develop envi-ronmentally friendly biological alternativesto chemical pesticides. Extensive locustspray campaigns in the 1980s caused publicconcern about the accompanying environ-mental impact of chemicals, and biologicalpest management methods are especiallyimportant in natural and semi-natural habi-tats. The programme has developed amycoinsecticide based on an isolate of thefungus Metarhizium anisopliae var.acridum, which has been field testedagainst a number of acridid pest species,and is now recognised as an appropriateproduct for locust control in environmen-tally sensitive areas. In a recent series ofoperational trials against Oedaleus senega-lensis, it was shown that although theorganophosphorus chemical fenitrothionachieves an impressive ‘knock down’,hopper populations recover and two weeksafter application a more profound popula-tion reduction was achieved in the plotssprayed at ULV rates with Metarhiziumconidia. Residues of the fungus were morepersistent than fenitrothion but had min-imal impact on nontarget organisms –which may have enhanced field efficacy.However, it is not sufficient simply to dem-onstrate efficacy and register products inthis way; there is a continuing need to pro-mote and ensure the continued supplies ofgood quality, cost effective formulations. Itappears that this is presently best achieved bypartnership between publicly funded researchgroups (such as LUBILOSA) and small- tomedium-sized commercial companies.

The Challenge

With the increasing supply of cheaper, con-siderably less toxic and more specificcompounds, an open mind is important inproviding reliable technical solutions tofarmers’ problems. Commercial pressureshave encouraged the excessive promotionof single technology (‘magic bullet’) con-cepts, which have not delivered all that waspromised. It is the use of techniques in com-bination with one another that offers thegreatest potential for farmers to reducecosts and impact on nontarget organisms.When it is accepted that pesticidal interven-tion is indeed occasionally necessary, thenRPU could provide a framework for inter-action between IPM practitioners andproviders of technical solutions. However,we must recognise that:

• In the interests of economic support,quality control and reliability of supply,RPU technologies (such as biopesti-cides, improved pest monitoring toolsand application techniques) are mostlikely to succeed when provided bycommercial concerns, rather than ruralcommunities.

• Alliances are needed between researchand development organizations and thesmall-to medium-scale industries thathave the best track record for sustainingRPU technologies.

• It is essential that farmers and otherusers understand the biological andtechnical concepts underlying thesetechnologies. The relationship betweentechnology providers (both institutionaland commercial) and the needs offarmers is also vital for the successfulimplementation of RPU and other IPMtechnologies.

• A re-examination of appropriateenvironmental and regulatory policiesat national and international level wouldalso be most helpful.

RPU is not a new paradigm, but a sub-set ofIPM. It recognises that pesticides have beenaround for more than a generation, and arelikely to be around for at least another.Seeing pesticides as dangerous (and con-versely biological control as safe) is over-simplistic and sometimes factually wrong.RPU is a mixture of old and new ideas tomanage real problems such as pesticideresistance and environmental impact and,of most interest to the farmer, to providerobust but economic pest management.

1Brent, K.J.; Atkin, R.K. (eds) (1987)Rational pesticide use. Cambridge, UK;Cambridge University Press, 348 pp.

By: Roy Bateman, CABI Bioscience,UK Centre (Ascot), Silwood Park,Buckhurst Road, Ascot, SL5 7TA, UKEmail: r.bateman@cabi.orgFax: +44 1491 829123

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Improving Hot Pepper Production in Jamaica

The Food and Agriculture Organization ofthe United Nations (FAO) is providingassistance to Jamaica, through a technicalcooperation project, to improve productionof its famous hot peppers (Capsicum spp.).At present, production and export of hotpeppers is one of Jamaica’s most importantagricultural activities and has been identi-fied as having great potential fordevelopment by the Government. Theindigenous Jamaican Scotch Bonnet,renowned for its unique characteristics, isone of the best known and most prized ofthe Caribbean varieties in the exportmarket. Over J$38 million (US$1.0 mil-lion) per annum are currently earned fromthe industry and more than 3000 people aredirectly or indirectly employed in it.

Maximizing production and hence returnsfrom the crop are constrained by a number

News 101N

of factors, the chief of which are a shortageof good quality seed and the impact of var-ious pests. The most important arthropodpests are gall midges (Contarinia lycoper-sici and Prodiplosis longifila), the broadmite (Polyphagotarsonemus latus) andaphids (Aphis gossypii and Myzus per-sicae). However, the gall midges constitutethe most pressing problem, because theyare considered pests of quarantine signifi-cance in the USA, which is a major marketfor the crop. Effective control measuresneed to be implemented urgently. Atpresent, farmers rely heavily on chemicalpest control methods – indeed, it is likelythat the gall midge problem could be pesti-cide induced.

The FAO project, which was initiated inApril 2000, aims to assist the Governmentof Jamaica with its hot pepper seed devel-opment programme, and amongst itsobjectives is the implementation of an IPMstrategy for effective control of gall midgesand broad mite. A number of preliminaryactivities have been initiated within the

IPM programme so far. These include:identification of demonstration farmers’plots, installation of equipment, identifica-tion of laboratory facilities at BodlesResearch Station, development of protocolsfor pesticide trials, looking at the role ofindigenous natural enemies and prelimi-nary laboratory studies on pest biology andtheir natural enemies. The Caribbean Agri-cultural Research and DevelopmentInstitute (CARDI) has also been under-taking studies on both the hot pepper pestsin question.

Farmer participatory research and trainingis also a key element of the FAO project.Towards this end, a national training work-shop on farmer participatory approacheswas undertaken in August 2000 where 15extension workers were trained to developand implement a farmer participatory IPMprogramme in six parishes in Jamaica. Oneconcrete outcome of the workshop wasprogress in the development of a proposedcurriculum framework for farmer trainingin hot pepper production techniques in

which participatory IPM will be a majorcomponent.

Source: Pollard, G. (2000) FAO Assistanceto Jamaica for improving hot pepper pro-duction, in part through development of anIPM programme for gall midges and broadmite. CaribbeanIPM Knowledge Network,Current Awareness Bulletin, No. 2 (Sep-tember 2000).

By: Gene V. Pollard,

Regional Plant Protection Officer,

FAO Sub-Regional Office for the

Caribbean, P.O. Box 631-C, Bridgetown,

Barbados, West Indies

Email: Gene.Pollard@fao.org

Fax: +1 246 427 6075

and

Lennox Chandler, FAO TCDC

Consultant, Ministry of Agriculture and

Rural Development, P.O. Box 505,

Graeme Hall, Barbados, West Indies

Email: lennoxchandler@excite.com

Fax: +1 246 420 8444

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Internet Round-up

In this issue, we give some Internet sitesdealing with mammal biocontrol, to gowith our news article on the subject. Aus-tralia and New Zealand are leaders in thisfield, and we concentrate on some of theirresources. As a biological island with itsown unique flora and fauna, Australia hassuffered massively from the hosts of mam-mals imported since European settlers firstcolonized the continent 200 years ago. TheAustralian Pest Animal Control CRC siteat:

http://www.pestanimal.crc.org.au

outlines pest problems caused by foxes,rabbits and mice, and their work to developcontrol methods for them. They arefocusing on immunocontraceptive vacinesand their delivery through baits or, byengaging biotechnology, through theagency of a virus genetically modified tocarry the vaccine. However, native animalsalso cause problems in Australia, and theAustralian Marsupial CRC works on theconservation of marsupials in their nativeenvironments combined with managementsolutions in problem situations. Researchon fertility, development, genetics, immu-nology and virology being used to developpractical fertility-based management solu-tions is described at:

www.newcastle.edu.au/marsupialcrc

Also on this site is the proceedings of a con-ference on Managing Marsupial Abundance

for Conservation Benefits held in Perth in1998:

http://www.newcastle.edu.au/marsupi-alcrc/marsupsymp/index.html#contents

New Zealand interests in mammal biocon-trol are described on the Landcare Researchsite <http://www.landcare.cri.nz>. TheBiosecurity and Pest Management page at:

http://www.landcare.cri.nz/science/biosecurity/

describes brushtail possums as thecountry’s worst vertebrate pests. ItsPossum Information Pages <http://www.landcare.cri.nz/science/possums/>have information on their biological controlincluding immunocontraceptive and fer-tility control techniques. Reflecting theconcern about possums is the presence of asearchable bibliography at:

http://possum.massey.ac.nz

and lists of current research projects on pos-sums (mostly in New Zealand) and abibliography that includes many unpub-lished reports are also available in theAnnual Reports of the National ScienceStrategy Committee for the Control ofPossum and Bovine Tb at:

http://www.frst.govt.nz/public/possum/index.htm

In general, rabbit biocontrol in Australiaand New Zealand probably springs most

readily to mind when mammal biocontrol ismentioned. Information on rabbit haemor-rhagic/calicivirus disease (RHD/RCD)introduction to Australia is archived at:

http://www.csiro.au/communication/rabbits/rabbits.htm

As well as providing extensive backgroundto the rabbit problem and disease solutions,and a detailed guide to using and managingRHD in the field, it also describesresponses to the accidental escape of thevirus from quarantine Also interesting isthe New Zealand Rabbit Biocontrol Advi-sory Group (RBAG) site at:

http://www.maf.govt.nz/MAFnet/arti-cles-man/rbag/httoc.htm

The site comprises an information kitdesigned to bring together an overview ofrabbit impacts, trends in pest managementand information on RHD. RBAG was dis-banded when permission to importcalicivirus was received, but the site is agood source of information, some of it nowof historical interest (for example, amongfrequently asked question, “Is RHD likelyto arrive naturally in New Zealand? …anillegal introduction cannot be dis-counted…”). It provides an overview ofviruses, mutation, and host specificity andswitching in the context of the rabbitcalicivirus.

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102N BiocontrolNews and Information 2000 Vol. 21 No. 4

Announcements

Are you producing a newsletter, holding ameeting, running an organization orrearing a natural enemy that you wantother biocontrol workers to know about?Send us the details and we will announce itin BNI.

Pilot in the Caribbean

CAB International in collaboration with theCaribbean Agricultural Research andDevelopment Institute’s (CARDI) Carib-bean Agricultural Information Service andPROCICARIBE’S Caribbean IPM Net-work have set up a pilot KnowledgeNetwork for IPM experts in the region. Theprimary target group is invited scientistsand agriculturists in the Caribbean region,but key resource people from other geo-graphic regions are also invited toparticipate to widen the knowledge base.The information on the network will belargely based on communications posted bythe group’s members. The network willsolicit and disseminate the following fourtypes of information:

• Short ‘keynote’ papers on specificsubjects, posted with the objective ofstimulating discussion among groupmembers.

• Summary papers of member contribu-tions for each topic area.

• A ‘current awareness service’ includingcontents and abstracts from internationaland national bibliographic databases,supported by provision of full text of keydocuments (copyright permitting) ineither hardcopy or electronic format.

• Announcements of relevant regional/international meetings, workshops, andcourses.

The Internet provides new opportunities foragricultural research organizations to shareand disseminate information. While noteveryone in the Caribbean region yet hasInternet access, even rurally-based scien-tists are beginning to be connected to email.The demand is growing, and most govern-ments, recognising its potential, areinvesting in new information technologyeven in a period of economic austerity.Soon, many more scientists and farmerswill be able to access and use email to par-ticipate in this kind of knowledge network.The pilot will therefore be evaluated, andfrom this recommendations on the structureand composition of future Knowledge Net-works in the region will be formulated. It isanticipated that the IPM Knowledge Net-

work will continue in some form, asdiscussed and agreed among the members.

Contact: Moses Kairo,

CABI Caribbean and Latin American

Centre, Gordon Street, Curepe,

Trinidad & Tobago, W.I.

Email: m.kairo@cabi.org

Fax: +1 868 663 2859

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Knapweed Symposium

An international knapweed symposiumwill be held in Coeur d’Alene, Idaho, USAon 15-16 March 2001, in conjunction withthe annual Western Society of Weed Sci-ence meeting. The purpose of theSymposium is to present new informationon the biology, ecology, and managementof Centaurea (sensu latu) species(including spotted knapweed, diffuse knap-weed, squarrose knapweed, Russianknapweed and yellow starthistle). The sym-posium is sponsored by the WesternSociety of Weed Science, in cooperationwith the US Forest Service, Bureau of LandManagement, USDA Agriculture ResearchService, University of Idaho, WesternWeed Coordinating Committee, the IdahoDepartment of Agriculture, and DowAgro-sciences. For further information see thewebsite at: http://www.sidney.ars.usda.gov/knapweed/

Contact: Lincoln Smith,USDA-ARS-WRRC-EIW,800 Buchanan Street, Albany,CA 94710, USAEmail: lsmith@pw.usda.gov

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Cuba Hosts Plant Health Seminar

The IVth International Scientific Seminarof Plant Health will take place in Varadero,Cuba on 11-15 June 2001. The followingscientific meetings will take place:

• IV International Scientific Seminar ofPlant Health

• X Latin American Workshop of White-flies-Geminiviruses

• 33rd Annual Meeting of the Organi-zation of Nematologists of TropicalAmerica (ONTA 2001)

• 41st Annual Meeting of the AmericanPhytopathological Society, CaribbeanDivision (APS-CD 2001)

• VII Symposium of Ant Pests

• II Latin American Congress of theNeotropical Regional Section of theInternational Organization for BiologicalControl

• Workshop for scientific information onplant protection

• International workshop on pests anddiseases in banana: current situation andchallenges for the new century(INISAV-CENSA-PROMUSA)

Contact: Dra. Ileana Sandoval,Calle 110 # 514 e/5ta B y 5ta F. Playa,CP 11600, Ciudad de La Habana, CubaEmail: isandoval@inisav.cu /inisav@ceniai.inf.cuFax: +53 7 240535

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Practising Biological Control

A conference entitled ‘The Practice of Bio-logical Control: Importation andManagement of Natural Enemies andAgents will be held on 2-5 August 2001 atMontana State University in Bozeman,USA. Conference details are given on thewebsite at:http://opal.msu.montana.edu/conf_services/biocontrol/index.htmRegistration is limited to the first 250 toregister.

The symposium is intended for practi-tioners in all disciplines of biologicalcontrol, including entomology, insectpathology, nematology, plant pathology,and weed science, and is co-sponsored bythe International Organization for Biolog-ical Control, Nearctic Regional Section(IOBC-NRS), the Experiment StationCommittee on Organization and Policy(ESCOP-BCWG) and the National Biolog-ical Control Institute (UDSD-APHIS-PPQ-CPHST-NBCI).

Contact Tim Kring, University of

Arkansas – Entomology,

Cralley-Warren Research Laboratories,

2601 N. Young Avenue, Fayetteville,

AR 72704, USA

Email: tkring@comp.uark.edu

Fax: +1 501 575 3348

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Fertility Control

The 5th International Symposium on Fer-tility Control in Wildlife will be held on 19-22 August 2001 at the Kruger NationalPark, South Africa. Topics covered will

News 103N

include current field applications, on-goingfield trials (including those in zoos or sanc-tuaries), research in progress (which willform the heart of the symposium), ethical,social, cultural and political aspects of pop-ulation control, and regulatory issues.

Contact: 5th International Symposium on

Fertility Control in Wildlife,

c/o Prof Henk Bertschinger,

Department of Reproduction,

University of Pretoria,

Private Bag X04, Onderstepoort 0110,

Republic of South Africa

Email: henkbert@op.up.ac.za

Fax: +27 12 529 8314

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Combating Invasive Plants

The 6th International Conference on theEcology and Management of Alien PlantInvasions (EMAPi) will be held on 12-15September 2001 at Loughborough Univer-sity, Leicestershire, UK. The organizers arecirculating a short questionnaire forintending participants to ensure that theconference will reflect the current interestsof alien plant invasion research.

Contact: Lois Child, Centre Co-ordinator,

Centre for Environmental Studies,

Loughborough University,

Loughborough,

Leicestershire, LE11 3TU, UK

Email: L.E.Child@lboro.ac.uk

Fax: +44 1509 222558Internet: http://www.lboro.ac.uk/research/cens

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Africa Online

African Journals Online (AJOL 2000) is awebsite offering on-line access to the tablesof contents and abstracts of articles fromsome 50 journals in agricultural sciences,science and technology, health and socialsciences, published in Africa.Internet: http://www.inasp.org.uk/ajol/

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104N BiocontrolNews and Information 2000 Vol. 21 No. 4