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Session ThreePest Disease Control Strategies, Integrated
Production Systems and the Impact on Market Access
Session ThreeSession ThreePest Disease Control Pest Disease Control Strategies, Integrated Strategies, Integrated
Production Systems and the Production Systems and the Impact on Market AccessImpact on Market Access
New Zealand and Australia Avocado Grower’s Conference’05 20-22 September 2005 Tauranga, New Zealand
New Zealand and Australia Avocado New Zealand and Australia Avocado GrowerGrower’’s Conferences Conference’’05 05 2020--22 September 2005 22 September 2005 TaurangaTauranga, New Zealand, New Zealand
Managing avocado pestsManaging avocado pests withwithromance, intrigueromance, intrigue and war and war ––
integrating pheromones, assassinsintegrating pheromones, assassins and and weapons of mass destructionweapons of mass destruction
Geoff WaitePrincipal Entomologist
Queensland Department of Primary Industries and FisheriesMaroochy Research Station
Nambour Queensland, Australia
Managing avocado pests withromance, intrigue and war –
integrating pheromones, assassins and weapons of mass destruction
Geoff WaitePrincipal Entomologist
Queensland Department of Primary Industries and FisheriesMaroochy Research Station
Nambour Queensland, Australia
In many districts, the Queensland avocado pest complex is dominated by fruitspotting bugs
Amblypelta nitida AmblypeltaAmblypelta lutescenslutescensThis presentation will focus
on these bugs as they arethe key pests in the system
Fruitspotting bug damageFruitspotting bug damage
The The RomanceRomanceFinding a mate
For an insect, what does finding a mate involve?
Being where the action is, helps!Host plants facilitate this by attracting insects to a common feeding site.
Either sex may produce the attractant pheromone, depending on the insect group
In moths, the female produces the pheromone
Males produce the pheromone in some weevils and true bugs
Fruitspotting bug males produce the pheromone
Note the interest in the mating pair from all these females
For insects, once they get to the venue, attraction to the opposite sex on the ‘dance floor’ is usually via pheromones.
Sex - a fatal flaw to be exploited in a species’ behaviour!
Aeration technique used for collecting fruitspotting bug pheromones
SPME sampler – allows direct desorption & analysis in Gas Chromatograph of pheromones & host volatiles
Volatile compounds (pheromones) adsorbed onto active film coating the fibre
Volatile compounds absorbed by activated charcoal or Poropak Q
Solid Phase Micro-extraction - SPMEAeration
Fruitspotting bugs have glands that produce defensive odours, but they have no discrete pheromone-producing glands.
For these bugs, the pheromones have to be collected from the airafter they are released to enable identification of the active compounds.
Compounds of particular Compounds of particular interest for each speciesinterest for each species
EE--ocimeneocimene epoxideepoxide((myroxidemyroxide))
EE--nerolidolnerolidol
Live bugs Amputating the antenna Antenna attached to electrodes
Simultaneous injection of aeration sample into EAG device and GC
Readout of antennal reaction (AEG) top graph,and active compounds (GC) lower graph
Antennal reaction to ocimene epoxide, nonanal and decanal
Sorting out the active compounds - USDA laboratory, Beltsville
ocimene-epoxidenonanal
decanal
Insect semiochemistryThe pheromone may work in combination with host volatiles – after all, wining and dining are a part of human romancing, so why not with bugs?
cineolecineole
nonanalnonanal
nonanalnonanal
cineolecineole
EE--ββ--ocimeneocimene
decanaldecanal
LonganLongan
Custard appleCustard apple
decanaldecanal
napthalenenapthalene
SPME samples of green fruit
These small flies have presumably been attracted by volatile chemicals –are these produced by the ‘stressed’ bee or the assassin bug?
Pheromones and host volatiles could be used:
In traps for monitoring populations
In an attract and kill strategy in combination with decoy trees
Female Amblypelta nitida on trap containing ocimene-epoxide, nonal and decanal
The IntrigueThe enemy within
In IPM systems, conservation biological control is criticalAssassins in action
RedbandedRedbanded thripsthrips infestation terminated by natural enemies infestation terminated by natural enemies -- on avocado in street in on avocado in street in BuderimBuderim
The WarThe War
Pesticides, weapons of mass destruction Pesticides, weapons of mass destruction of both of both beneficialsbeneficials and pests, are and pests, are indispensibleindispensible in most commercial orchards.in most commercial orchards.
Chemical warfare waged sensibly,Chemical warfare waged sensibly,generally produces quality fruit. generally produces quality fruit.
However ------
Inappropriate use of some types of chemical can cause problems, especially with scales
and mites
So, how should we respond to pest invasions?
The elements of ‘romance’ and ‘intrigue’ that are effective against individual pests should be applied (pheromones if available, conservation biological control)
Incorporate these in a practical and sustainable strategy that usestactical and targeted chemical warfare against pests for which other management options are not available
Sustainable IPM system
In addition to understanding pest biology, behavioural and ecological studies are criticalto determine opportunities for developing newmanagement strategies, especially for key pests.
Fruitspotting bugs have also exhibited preferences for certain avocado (and macadamia) cultivars, which could be used as trap trees in a ‘Hass’ orchard
For fruitspotting bugs, this has led to the formulation of the ‘hotspot’ strategy
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Fruitspotting bug damage on individual unsprayed trees of Fruitspotting bug damage on individual unsprayed trees of various avocado cultivars, Maroochy 2003various avocado cultivars, Maroochy 2003--0404
Typical fruitspotting bug hotspot situationTypical fruitspotting bug hotspot situation
Columns (distance in meters)
-100 -80 -60 -40 -20
Row
s(d
ista
nce
in m
eter
s)
10
20
30
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IPMapplied
849
849
849
849246
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246741
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741A 4
A 4
A 4
A 4
Fruitspotting bugdamage
0 %10 %20 %30 % 40 %50 %60 %
Standardchemical
Egg parasiteonly
Nutborerpheromone
Fruitspotting bug damage on macadamias 2003-04
Bug sourceBug source
Bug sourceBug source
Maddox & Huwer, 2004
Fruitspotting bug edge effect in passionfruit
Outside row: Undamaged fruit = 62Damaged fruit = 117
65.4%
Second row:Undamaged fruit = 169Damaged fruit = 6
3.4%
identifying and using hotspots to monitor fruitspotting bug infestations
spraying only the hotspots, but more frequently to prevent bug dispersal through the orchard
using more susceptible cultivars as decoy/trap treese.g. Fuerte
Romance, intrigue and tactical warfare can becombined in a total orchard management system (IPM)
for any avocado pest complex.
In Queensland, the system will be enhanced by:In Queensland, the system will be enhanced by:
Particle film (SurroundParticle film (Surround®)®) has beenhas been applied as an insect deterrent applied as an insect deterrent and sunscreen and sunscreen –– but it washes off in rain & may induce scale outbreaksbut it washes off in rain & may induce scale outbreaks
Exclusion nets are not an option in avocados