Host plants and relative abundance of fruit fly (Diptera: Tephritidae) species in the Solomon Islands

Australian Journal of Entomology

(2003)

42

, 95–108

Host plants and relative abundance of fruit fly (Diptera: Tephritidae) species in the Solomon Islands

Robert G Hollingsworth,

1

* Richard AI Drew,

2

Allan J Allwood,

3

Meredith Romig,

2

Maclean Vagalo

4

and Francis Tsatsia

4

1

US Pacific Basin Agricultural Research Center, USDA-ARS, PO Box 4459, Hilo, Hawaii 96720, USA.

2

Faculty of Environmental Sciences, Nathan Campus, Griffith University, Qld 4111, Australia.

3

Allan Allwood Agriconsulting, 61 Thornburgh Street, Oxley, Qld 4075, Australia.

4

Ministry of Agriculture and Primary Industries, PO Box G13, Honiara, Solomon Islands.

Abstract

Tephritid fruit flies were surveyed using male lure Steiner traps and by collection of host fruits over a4-year period (June 1994–June 1998) throughout the nine provinces of the Solomon Islands. Thepurpose of the survey was to determine which species were present, which were most abundant, andwhich commercial and non-commercial fruits were hosts for fruit flies. A total of 1 051 493 fruit flyspecimens were collected in 1726 trap collections from 117 sites. Sixty-three per cent of trap collectionswere made on the island of Guadalcanal. Overall, 37 fruit fly species were recovered from trap samples,with 79% and 21% of specimens from cuelure and methyl eugenol traps, respectively. The species mostcommon in cuelure traps were

Bactrocera frauenfeldi

(Schiner) (mango fly),

B. moluccensis

(Perkins),

B. simulata

(Malloch),

Dacus solomonensis

Malloch and

B. redunca

(Drew). The species most commonin methyl eugenol traps were

B. umbrosa

(Fabricius),

B. froggatti

(Bezzi) and

B. pepisalae

(Froggatt).With the exception of

B. cucurbitae

(Hendel), all common species were recovered in all provinces.

B. cucurbitae

was the only non-indigenous fruit fly species collected. The number of fruit fly speciesrecovered in each island group was significantly and positively related to trapping intensity. A total of2527 fruit samples were collected to determine host relationships for fruit flies. Tephritid fruit flieswere reared from fruits of 25 of the 67 commercial plant species sampled. However, fruit-survey dataindicated that there were only four economic species in the Solomon Islands: (i)

B. frauenfeldi

;(ii)

B. umbrosa

; (iii)

B. cucurbitae

; and (iv)

D. solomonensis

.

Bactrocera frauenfeldi

was identified asthe only generalist fruit fly species present, and many potential export crops were not hosts for any fruitfly species. These facts emphasise the importance of effective quarantine measures to prevent theaccidental introduction of exotic fruit fly pests that might limit or complicate the development of anexport industry for fruits and vegetables.

Key words

Bactrocera

,

Dacus

, fruit fly survey, host records, Oceania, trapping records.

INTRODUCTION

The Solomon Islands is an independent nation consistingof about 30 ‘high’ islands and numerous atolls (total area28 446 km

2

) in the south-west Pacific Ocean, east of NewGuinea. The larger islands are mountainous and thicklyforested. This island group stretches almost 900 km fromnorth to south, and over 1800 km from east to west, includingthe isolated islands of Temotu Province, located approxi-mately 400 km east of Makira Island (Fig. 1). Given its soils,abundant rainfall and warm, equatorial climate, the SolomonIslands has the potential to produce high-quality, high-valuefruit crops for export to Pacific Rim countries. A fruit-exporting industry would bring in much needed income andforeign capital, while preserving, to a large extent, both the

environment and the traditional village lifestyle. However,the Solomon Islands is not currently exporting any freshfruits or vegetables. In most areas of the country, fruits andvegetables are produced for subsistence only and there arefew local markets for produce outside of the capital city ofHoniara (northern Guadalcanal). Primary export constraintsinclude lack of transportation infrastructure, lack of entre-preneurs, and quarantine barriers associated with fruit flies.

Worldwide, there are approximately 4500 describedspecies of fruit flies in the family Tephritidae (Drew &Romig 1997). The great majority of the fruit fly species inthe South Pacific region are indigenous non-pest speciesin the genus

Bactrocera

, subfamily Dacinae. The larvae ofdacine flies typically infest fleshy fruits. The larger landmasses of the South Pacific and adjacent island groups haverelatively more diverse faunas of dacine fruit flies. Forexample, 173 species of dacine fruit flies are known fromPapua New Guinea (Drew & Romig 1997), whereas Vanuatu

*Author to whom correspondence should be addressed (email:[email protected]).

96

RG Hollingsworth

et al

.

and New Caledonia have only 13 species each (Allwood

et al

. 1997; Amice & Sales 1997). Recently, Drew & Romig(2001) catalogued 49 species of dacine fruit flies fromthe Solomon Islands. Although the great majority of thesespecies are of no economic importance, others may attackcommercial plants, and data are needed to demonstrate whichspecies should be considered quarantine risks. Importingcountries generally require exporting countries to supplyinformation on the species of tephritid fruit fly present, toidentify which species are pests, and to describe the hoststhey attack. If a particular commodity proposed for exportis attacked by a fruit fly pest, the importing country willgenerally require the use of a commodity treatment (such asheat or cold) to kill fruit flies prior to export.

The main goals of the present study were to: (i) conducta nation-wide survey for fruit flies; (ii) determine whichspecies were most abundant; and (iii) discover which com-mercial and non-commercial fruits were attacked. Thisinformation is needed to support the development of anexport industry for fruit and vegetable crops.

MATERIALS AND METHODS

Survey methods for fruit flies in the Pacific region includerearing flies from collected fruits and collecting males intraps baited with cuelure or methyl eugenol. The males of90% (57 out of 63) of known fruit fly species in seven Pacific

Island countries have been shown to be attracted to eithercuelure or methyl eugenol (Allwood 1997).

Trapping

Male fruit flies were trapped using Steiner fruit fly traps(Queensland modification) (Drew 1982a). Each trapping siteincluded a pair of traps, one baited with cuelure and the otherwith methyl eugenol. Traps were hung from trees and thetwo traps at each site were generally spaced at least 20 mapart. The liquid lure was mixed with malathion (50% activeingredient, emulsifiable concentrate formulation) at a ratio of4 : 1. Between 3 mL and 5 mL of the mixture containing thelure was absorbed into a piece of cotton dental wick. Flieswere collected from traps at various time intervals, butgenerally every 2–4 weeks. Wicks containing lure/insecticidemixture were re-charged or replaced at various time intervals,but generally every 3 months. Traps were protected from antsvia a coating of sticky material (Tanglefoot; The TanglefootCompany, Grand Rapids, MI, USA) applied to the wiresfrom which traps were hung.

Trapping sites were located on all major islands (chieflyin coastal areas within villages) and in all nine provinces.Traps were monitored by project staff or their cooperators(Agricultural Extension and Quarantine Officers of theMinistry of Agriculture and Primary Industries). Flies werecollected into cardboard boxes and posted to Dodo CreekResearch Station (Guadalcanal) where fruit flies were frozen(to kill mites), dried and sorted, then shipped to the laboratory

Fig. 1. Major islands of theSolomon Islands. Except forWestern, Renbel, Temotu andCentral Provinces, the prov-inces are named for the majorislands that they encompass.Central Province (not labeled)includes the group of islandsbetween Guadalcanal andIsabel.

Solomon Islands fruit flies

97

of RAI Drew (Griffith University, Brisbane, Australia) foridentification or confirmation of identity.

Fruit collections

To determine host associations of fruit flies, wild and culti-vated fruits were collected during special fruit collection tripsand opportunistically while checking fruit fly traps along thecoastal road of northern Guadalcanal. Fruit collecting wasconcentrated along northern Guadalcanal for convenience,because the road system is poorly developed in the SolomonIslands. Fruit samples were collected from the ground (as‘windfalls’) or from the tree. Whenever possible, ripe orfallen fruits were selected, because these are more likely tobe infested than unripe fruit. When fruits were collected froman unknown plant, a plant sample was collected and submit-ted for identification to staff of the National Herbarium(Ministry of Forestry, Environment and Conservation,Honiara). Photographs were taken of many plant samplesto assist in plant identification. Fruits were transported tothe laboratory within paper bags. Then they were weighed,counted, and placed within plastic mesh-covered containerson top of moist, heat-sterilised sawdust. Fruit samples thatwere expected to produce an excess of liquid were set upwithin boxes, on top of mesh-covered containers thatcollected fruit juices but excluded fruit fly larvae. In theseboxes, moist sawdust was also used in the bottom as apupation medium. Sample containers were checked for pupaeand adult flies at approximately 7-day intervals. Pupae weresieved from sawdust and held for adult emergence. Alterna-tively, samples were left intact until adult fruit flies hademerged. Adult fruit flies were fed sugar and water for 5 daysuntil body colour had fully developed and then they wereallowed to die within containers or were killed by freezing.Fruit samples were discarded after about 4 weeks.

A fruit sample was categorised as being from a ‘com-mercial host’ if: (i) the fruit was normally sold at localmarkets; (ii) the host plant bore fruits of export potential; or(iii) the host plant was in the same genus with a com-mercial host. It should be noted that certain plants inthe non-commercial category are important food plantslocally. In computing the total number of commercial or

non-commercial host plant species, hosts identified only togeneric level were not counted if host-record data wereavailable for one or more species within the same genus.

RESULTS

Trapping

Between 21 June 1994 and 1 June 1998, 1726 samplecollections (950 cuelure and 776 methyl eugenol) were madefrom 117 sites throughout the nine provinces of the SolomonIslands. The majority (1092) of collections were made inGuadalcanal Province (Table 1). There were 37 species offruit flies identified from the trap samples (Tables 2 and 3).Twenty-five of these species were attracted to cuelure and 12were attracted to methyl eugenol. The species that weremost common in cuelure traps (in decreasing order) were

B. frauenfeldi

,

B. moluccensis

(Perkins),

B. simulata

(Malloch),

Dacus solomonensis

Malloch, and

B. redunca

(Drew). Thesespecies were recovered from 982, 863, 596, 528 and 410 trapcollections, respectively (Table 3). The average number of

B. frauenfeldi

per trap sample ranged from 108 (ChoiseulProvince) to 1226 (Temotu Province) (Table 2). The speciesmost common in methyl eugenol traps (in decreasingorder of frequency) were

B. umbrosa

,

B. froggatti

(Bezzi)and

B. pepisalae

(Froggatt). These species were recoveredfrom 772, 535, and 460 trap collections, respectively(Table 3). The average number of

B. umbrosa

per trapsample ranged from 16 (Renbel Province) to 1136 (MakiraProvince) (Table 2).

Bactrocera cucurbitae

(Hendel) wasthe only exotic pest fruit fly identified from trap samples. Itwas recovered from all provinces in the Solomon Islandsexcept Makira, Renbel and Temotu. With the exception of

B. cucurbitae

, all common species were recovered from allprovinces.

Five fruit fly species were collected in only one or twotrap samples, and six species previously collected in traps inthe Solomon Islands were not detected during our study(Table 3). A regression of the number of species recovered ineach province against trapping intensity (log of the numberof trap collections) was significant (

y

= 12.5

x

– 6.1;

r

2

= 0.62;

P

= 0.01; d.f. = 1, 7) (Fig. 2).

Table 1

Number of sites and total trap collections (methyl eugenol and cuelure) in each province from June 1994 to June 1998

Province No. sites 1994 1995 1996 1997 1998 Total collections

Central 9 1 41 62 68 3 175Choiseul 15 2 3 29 22 5 61Guadalcanal 42 198 255 309 274 56 1092Isabel 7 0 0 64 35 1 100Makira 4 0 0 10 0 11 21Malaita 9 0 36 46 0 0 82Renbel 6 0 0 19 2 0 21Temotu 8 0 12 34 16 11 73Western 17 0 7 40 43 11 101Total 117 201 354 613 460 98 1726

98

RG Hollingsworth

et al

.

Table 2

Relative abundance of fruit fly species in male lure traps in each province

Province Genus (Subgenus) Species Lure No. positive trap catches (%)

Mean no. flies/positive trap catch

Central

Bactrocera (Bactrocera) atrabifasciata

CUE 1 (0.6) 1.0

biarcuata

ME 12 (6.9) 2.2

confluens

ME 4 (2.3) 1.8

decumana

CUE 17 (9.7) 6.1

epicharis

CUE 2 (1.1) 1.0

frauenfeldi

CUE 110 (62.9) 1102.3

froggatti

ME 75 (42.9) 78.1

melanogaster

ME 7 (4.0) 1.4

moluccensis

CUE 98 (56.0) 86.4

nigrescentis

CUE 1 (0.6) 1.0

parafroggatti

ME 2 (1.1) 1.0

pepisalae

ME 34 (19.4) 5.6

phaea

CUE 3 (1.7) 11.3

picea

ME 7 (4.0) 1.4

pseudodistincta

CUE 1 (0.6) 1.0

redunca

CUE 44 (25.1) 6.9

simulata

CUE 16 (9.1) 1.9

umbrosa

ME 88 (50.3) 155.1

Bactrocera (Zeugodacus) cucurbitae

CUE 3 (1.7) 22.0

Dacus (Callantra) solomonensis

CUE 20 (11.4) 4.9Choiseul

Bactrocera (Bactrocera) biarcuata

ME 7 (11.5) 1.3

decumana

CUE 9 (14.8) 2.3

frauenfeldi

CUE 31 (50.8) 108.1

froggatti

ME 29 (47.5) 44.7

melanogaster

ME 1 (1.6) 1.0

moluccensis

CUE 27 (44.3) 51.9

naucleae

ME 3 (4.9) 2.3

nigrescentis

CUE 2 (3.3) 1.0

parafroggatti

ME 2 (3.3) 5.5

pepisalae

ME 17 (27.9) 6.2

picea

ME 2 (3.3) 1.5

pseudodistincta

CUE 3 (4.9) 1.3

redunca

CUE 5 (8.2) 3.4

simulata

CUE 5 (8.2) 2.2

umbrosa

ME 30 (49.2) 90.9

unitaeniola

CUE 1 (1.6) 2.0

Bactrocera (Hemizeugodacus) buinensis

CUE 1 (1.6) 1.0

Bactrocera (Zeugodacus) cucurbitae

CUE 22 (36.1) 55.0

Dacus (Callantra) solomonensis

CUE 2 (3.3) 1.0Guadalcanal

Bactrocera (Bactrocera) bancroftii

ME 7 (0.6) 1.3

biarcuata

ME 41 (3.8) 3.0

confluens

ME 75 (6.9) 1.5

decumana

CUE 96 (8.8) 6.7

enochra

CUE 4 (0.4) 1.3

epicharis

CUE 11 (1.0) 2.8

frauenfeldi

CUE 642 (58.8) 771.1

froggatti

ME 359 (32.9) 27.4

melanogaster

ME 89 (8.2) 6.8

moluccensis

CUE 606 (55.5) 52.4

morula

CUE 19 (1.7) 12.1

naucleae

ME 6 (0.5) 1.3

nigrescentis

CUE 14 (1.3) 2.5

parafroggatti

ME 30 (2.7) 5.9

pepisalae

ME 366 (33.5) 8.9

phaea

CUE 13 (1.2) 4.2

picea

ME 83 (7.6) 4.4

pseudodistincta

CUE 16 (1.5) 2.8

reclinata

ME 1 (0.1) 1.0

redunca

CUE 332 (30.4) 14.5

simulata

CUE 493 (45.1) 26.0

umbrosa

ME 478 (43.8) 244.4

unifasciata

CUE 2 (0.2) 2.0

unitaeniola

CUE 7 (0.6) 1.0

Bactrocera (Sinodacus) hamaceki

CUE 27 (2.5) 1.9

Solomon Islands fruit flies

99

Table 2

Continued



Bactrocera (Sinodacus) hamaceki CUE 27 (2.5) 1.9univittata CUE 3 (0.3) 1.0

Bactrocera (Zeugodacus) abdoangusta CUE 20 (1.8) 1.2cucurbitae CUE 108 (9.9) 45.2fuscipennula CUE 5 (0.5) 1.2

Dacus (Callantra) solomonensis CUE 482 (44.1) 13.7Isabel Bactrocera (Bactrocera) aterrima CUE 3 (3.0) 2.7

atrabifasciata CUE 7 (7.0) 2.6biarcuata ME 2 (2.0) 1.0decumana CUE 20 (20.0) 12.5enochra CUE 8 (8.0) 2.4frauenfeldi CUE 52 (52.0) 742.4froggatti ME 25 (25.0) 32.6melanogaster ME 14 (14.0) 4.1moluccensis CUE 51 (51.0) 26.0naucleae ME 19 (19.0) 4.6nigrescentis CUE 9 (9.0) 10.4pepisalae ME 4 (4.0) 1.5phaea CUE 1 (1.0) 1.0picea ME 3 (3.0) 5.3pseudodistincta CUE 10 (10.0) 30.5redunca CUE 22 (22.0) 4.6simulata CUE 26 (26.0) 20.7umbrosa ME 43 (43.0) 140.3unifasciata CUE 1 (1.0) 1.0unitaeniola CUE 5 (5.0) 1.4

Bactrocera (Sinodacus) hamaceki CUE 1 (1.0) 1.0univittata CUE 12 (12.0) 6.6

Bactrocera (Zeugodacus) abdoangusta CUE 2 (2.0) 1.5amoena CUE 2 (2.0) 1.0cucurbitae CUE 21 (21.0) 21.0

Dacus (Callantra) solomonensis CUE 13 (13.0) 5.4Makira Bactrocera (Bactrocera) biarcuarta ME 3 (14.3) 2.0

decumana CUE 5 (23.8) 3.0frauenfeldi CUE 10 (47.6) 821.4froggatti ME 1 (4.8) 10.0moluccensis CUE 10 (47.6) 228.2morula CUE 1 (4.8) 1.0parafroggatti ME 2 (9.5) 1.0pepisalae ME 12 (57.1) 44.8pseudodistincta CUE 3 (14.3) 1.3simulata CUE 5 (23.8) 3.2umbrosa ME 14 (66.7) 1136.1

Dacus (Callantra) solomonensis CUE 3 (14.3) 3.3Malaita Bactrocera (Bactrocera) confluens ME 1 (1.2) 1.0

decumana CUE 7 (8.5) 1.7epicharis CUE 1 (1.2) 1.0frauenfeldi CUE 42 (51.2) 486.2froggatti ME 3 (3.7) 2.3moluccensis CUE 33 (40.2) 7.8pepisalae ME 23 (28.0) 10.3pseudodistincta CUE 1 (1.2) 1.0redunca CUE 4 (4.9) 1.5simulata CUE 17 (20.7) 4.4umbrosa ME 38 (46.3) 116.3

Bactrocera (Zeugodacus) abdoangusta CUE 1 (1.2) 1.0cucurbitae CUE 1 (1.2) 2.0

Dacus (Callantra) solomonensis CUE 6 (7.3) 2.5Renbel Bactrocera (Bactrocera) frauenfeldi CUE 15 (71.4) 445.1

froggatti ME 1 (4.8) 79.0moluccensis CUE 11 (52.4) 35.1nigrescentis CUE 2 (9.5) 2.0parafroggatti ME 1 (4.8) 20.0pseudodistincta CUE 12 (57.1) 7.2

100 RG Hollingsworth et al.

Fruit collections

A total of 2527 fruit samples were collected from: Guadal-canal (2264 samples); Western Province (97 samples); IsabelProvince (46 samples); Malaita Province (32 samples);Temotu Province (36 samples); Central Province (14 sam-ples); and Choiseul Province (38 samples). Valid data wereavailable for 2082 samples. Data were omitted if plantidentification was missing or uncertain (276 samples), or ifresults were otherwise incomplete or missing (169 samples).For 30 fruit sample records considered valid, the only avail-able plant identifiers were common names (no scientificnames).

Species of tephritid fruit flies were reared from 38%(n = 67) of commercial plant species from which fruitsamples were collected (Table 4). Bactrocera frauenfeldiwas the fruit fly species with the widest host range. The besthosts for B. frauenfeldi, as determined by the number of fliesproduced per kilogram of fruit, were Diospyros ebenum

J. König (ebony), Inocarpus fagifer (Parkinson) Fosb. (Poly-nesian chestnut), and Syzygium malaccense (L.) Merr. &Perry (Malayan apple) (Table 4). Other good hosts werePsidium guajava L. (guava) and Mangifera indica L.(mango). Bactrocera frauenfeldi was also reared fromDiospyros digyna Jacq. (black sapote), Carica papaya L.(papaya), Achras sapota L. (sapodilla), Annona muricata L.(soursop), Persea americana Mill. (avocado), Fortunellajaponica (Thunb.) Swingle (cumquat), Averrhoa carambolaL. (carambola), Citrus spp. (grapefruit, pomelo, sour orange),Barringtonia edulis Seem. (cutnut), Artocarpus altilis (Park.)Fosb. (breadfruit), A. heterophyllus Lamk. (jackfruit), andTrichosanthes cucumerina L. (snake gourd).

Bactrocera cucurbitae (melon fly) was reared fromTrichosanthes cucumerina L. (snake gourd), Cucumis sativusL. (cucumber), and Citrullus lanatus (Thunb.) Matsum. &Nakai (watermelon). Bactrocera moluccensis was rearedfrom Polynesian chestnut. Bactrocera umbrosa was rearedfrom breadfruit and jackfruit. Bactrocera quadrisetosa was

Table 2 Continued



simulata CUE 2 (9.5) 1.0umbrosa ME 5 (23.8) 16.2

Temotu Bactrocera (Afrodacus) minuta CUE 4 (5.5) 11.3Bactrocera (Bactrocera) frauenfeldi CUE 35 (47.9) 1226.0

hollingsworthi CUE 2 (2.7) 2.5moluccensis CUE 2 (2.7) 24.0nigrescentis CUE 2 (2.7) 1.0pseudodistincta CUE 1 (1.4) 1.0redunca CUE 4 (5.5) 2.8simulata CUE 13 (17.8) 30.3umbrosa ME 39 (53.4) 884.2

Western Bactrocera (Bactrocera) aterrima CUE 1 (1.0) 1.0atrabifasciata CUE 2 (2.0) 1.0biarcuata ME 13 (12.9) 2.1decumana CUE 5 (5.0) 4.8enochra CUE 1 (1.0) 1.0epicharis CUE 1 (1.0) 2.0frauenfeldi CUE 45 (44.6) 122.1froggatti ME 42 (41.6) 46.8melanogaster ME 7 (6.9) 1.7moluccensis CUE 25 (24.8) 10.3morula CUE 1 (1.0) 3.0nigrescentis CUE 3 (3.0) 1.3obliquivenosa ME 1 (1.0) 1.0parafroggatti ME 1 (1.0) 1.0pepisalae ME 4 (4.0) 3.5picea ME 11 (10.9) 4.5pseudodistincta CUE 1 (1.0) 2.0redunca CUE 3 (3.0) 1.0simulata CUE 19 (18.8) 21.3umbrosa ME 37 (36.6) 83.2

Bactrocera (Hemizeugodacus) buinensis CUE 1 (1.0) 4.0Bactrocera (Sinodacus) hamaceki CUE 1 (1.0) 1.0

univittata CUE 1 (1.0) 1.0Bactrocera (Zeugodacus) cucurbitae CUE 42 (41.6) 25.2

fuscipennula CUE 2 (2.0) 1.0Dacus (Callantra) solomonensis CUE 2 (2.0) 1.0

CUE, cuelure; ME, methyl eugenol.

Solomon Islands fruit flies 101

reared from Pometia pinnata Forst. F. Bactrocera calo-phylli was reared from papaya (four specimens) (anomalousrecord). Dacus solomonensis was reared from cucumber,snake gourd and Cucurbita pepo L. var. medullosa Alef.

(pumpkin). Potential export crops that were not attacked byany fruit fly species included banana, pineapple, mango-steen, rambutan, capsicum, tomato, eggplant and beans(Vigna marina (Burm. f.) Merr. and Vigna sesquipedalis (L.)

Table 3 List of Bactrocera and Dacus fruit fly species present in the Solomon Islands based on Drew & Romig (2001) and associatedtrapping data and fruit collections

Genus (Subgenus) Species Lure No. trap collections

(1994–1998)

Host plants identified

Bactrocera (Afrodacus) minuta (Drew) CUE 4 NoneBactrocera (Bactrocera) aithogaster Drew† UNK 0 None

aterrima (Drew) CUE 4 Noneatrabifasciata Drew‡ CUE 10 Nonebancroftii (Tryon) ME 7 Nonebiarcuata (Walker) ME 78 Noneconfluens (Drew) ME 80 Nonedecumana (Drew) CUE 159 Burckella sp.enochra (Drew) CUE 13 Noneepicharis (Hardy) CUE 15 Nonefrauenfeldi (Schiner) CUE 982 19 commercial and 11 non-commercial fruit

speciesfroggatti (Bezzi) ME 535 Nonefurvescens Drew† CUE 0 Nonehollingsworthi Drew‡ CUE 2 Nonelongicornis Macquart† CUE 0 Nonemelanogaster Drew ME 118 Nonemoluccensis (Perkins) CUE 863 Inocarpus fagifermorula Drew CUE 21 Nonenaucleae Drew‡ ME 28 Nauclea sp.neonigrita Drew† ME 0 Nonenigrescentis (Drew) CUE 33 Noneobliquivenosa Drew‡ ME 1 Noneparafroggatti Drew‡ ME 38 Nonepepisalae (Froggatt) ME 460 Nonephaea (Drew) CUE 17 Nonepicea (Drew) ME 106 Nonepseudodistincta (Drew) CUE 48 Nonequadrisetosa (Bezzi) UNK 0 Pometia pinnatareclinata Drew ME 1 Noneredunca (Drew) CUE 410 Nonesimulata (Malloch) CUE 596 Coccinea grandisumbrosa (Fabricius) ME 772 Artocarpus spp., Polyscias sp.¶unifasciata (Malloch) CUE 3 Noneunipunctata (Malloch)† UNK 0 Noneunitaeniola Drew‡ CUE 13 None

Bactrocera (Bulladacus) pacificae Drew‡ UNK 0 Gnetum gnemonpenefurva Drew UNK 0 Terminalia catappa

Bactrocera (Gymnodacus) calophylli (Perkins and May) UNK 0 Calophyllum inophyllumhastigerina (Hardy) UNK 0 Spondias cytherea

Bactrocera (Hemizeugodacus) buinensis Drew CUE 2 NoneBactrocera (Sinodacus) hamaceki Drew‡ CUE 29 None

univittata (Drew) CUE 16 NoneBactrocera (Tetradacus) pagdeni (Malloch)† UNK 0 NoneBactrocera (Zeugodacus) abdoangusta (Drew) CUE 23 None

amoena (Drew) CUE 2 Nonecucurbitae (Coquillett) CUE 197 Three commercial and one non-commercial hosts

(all Cucurbitaceae)fuscipennula Drew‡ CUE 7 None

Dacus (Callantra) solomonensis Malloch CUE 528 Cucumis sativus; Trichosanthes cucumerina,Cucurbita pepo (pumpkin)

†Species identified in trapping surveys prior to 1994 and not recollected during the 1994–98 survey period; ‡new species (described in Drew &Romig 2001) discovered during survey work for the present study; ¶questionable record. CUE, cuelure; ME, methyl eugenol; UNK, unknown lureresponse.


Fruhw.). Although citrus was sometimes attacked byB. frauenfeldi, it was a poor host.

From non-commercial hosts, species of fruit flies werereared from 27 of the 233 plant species collected (11.6%)(Table 5). Due to the size of the data set, only positive dataare presented (the complete data set is available uponrequest). Eleven species of Bactrocera were reared from non-commercial fruits (Table 5). As with commercial hosts,B. frauenfeldi was the tephritid species with the largest hostrange, being reared from 13 non-commercial species. Themost important wild host for B. frauenfeldi was Terminaliacatappa L. (tropical almond), which is common in coastalareas in the Solomon Islands. Other non-commercial hostsfor B. frauenfeldi included Broussonetia papyrifera L.(Vent.) (paper mulberry), Calophyllum spp., Cerberamanghas L., Ficus sp., Guettarda speciosa L., Nauclea sp.,Scaevola taccada (Gaertn.) Roxb., Spondias cytherea Sonn.,Terminalia whitmorei Coode and two unidentified hosts.

The only wild host of B. cucurbitae identified in thepresent study was Coccinea grandis L. (scarlet ivy gourd). Asingle specimen of B. umbrosa was recorded as being rearedfrom Polyscias sp. (anomalous record). Dacus solomonensiswas reared from a variety of small-fruited pumpkin thatgrows wild on trees in certain areas of Guadalcanal.

Combining data from trap collections, fruit collectionsand previous surveys carried out by other researchers, thereare 49 described species of fruit flies in the genera Bactro-cera and Dacus present in the Solomon Islands, with hostsand lure responses known for 13 and 41 species, respectively(Table 3).

DISCUSSION

Data from fruit and trapping collections indicated that noexotic fruit fly pests are present in the Solomon Islandsexcept B. cucurbitae (melon fly). Bactrocera cucurbitae wasdiscovered in Western Province in 1984, apparently having

arrived via Bougainville Island in adjacent Papua NewGuinea. Bactrocera cucurbitae has been gradually spreadingeast across the Solomon Islands since that time (Hollings-worth et al. 1997) and currently is found in six of the nineprovinces in the Solomon Islands. It has not yet spread tothe provinces of Makira, Renbel or Temotu. The pest statusof B. cucurbitae in the Solomons is underestimated in ourfruit collection data, because most of our fruit samples werecollected along northern Guadalcanal, and melon fly wasestablished in only a small portion of this area including andsurrounding Honiara town. Melon fly is a serious pest wherecucurbit crops are grown intensively, such as in parts ofWestern Province. In a separate study previously carried outin the Honiara area of Guadalcanal, melon fly was recordedfrom scarlet ivy gourd (C. grandis), bitter melon (Momordicacharantia L.) and cucumber (Hollingsworth et al. 1997;Hollingsworth unpubl. data 1998). Psytallia fletcheri (Silvestri)(Hymenoptera: Braconidae), a parasite of B. cucurbitae, wasintroduced to the Solomon Islands from Hawaii in 1997 andreleased on Guadalcanal and Western Province for control ofmelon fly. The parasite has established in the Honiara area,as it has been recovered from samples of C. grandis infestedwith melon fly.

Significantly, trapping data from the Solomon Islands didnot indicate the presence of B. papayae Drew and Hancock(papaya fruit fly), which is considered to be the mostdestructive of the oriental fruit fly species complex (Drew &Romig 1997). During the 1990s, B. papayae was discoveredand eradicated in northern Queensland (Australia). It occursin Papua New Guinea, where it is confined to the mainland.This species has been recorded from 209 host fruit speciesin South-East Asia (Drew & Romig 1997) and representsperhaps the greatest quarantine risk to fruit and vegetableproduction in the Pacific region.

Data from commercial fruit collections indicates thatthere are only four economic species in the SolomonIslands, as judged by ability to infest the edible portions ofcommercial crops. These species are: (i) B. frauenfeldi;(ii) B. umbrosa; (iii) B. cucurbitae; and (iv) D. solomonensis.Of these, B. frauenfeldi is the only generalist fruit fly pest,because B. umbrosa attacks only Artocarpus spp., whileB. cucurbitae and D. solomonensis are specialists on cucurbitcrops. It is significant that so few economic pests are presentin the Solomon Islands, because this greatly simplifies theresearch necessary for developing quarantine treatments tofacilitate the export of commodities that are hosts for fruitflies.

Although B. moluccensis and B. quadrisetosa were rearedfrom Polynesian chestnut and Pometia pinnata, respectively,they infested only the fleshy pericarp of these nut crops.Because it is doubtful that infestation by these flies reducesnut yields, they were not classified as economic pests.Surprisingly, four specimens of B. calophylli from onesample were reared from papaya. This species is a specialiston Calophyllum sp. (Allwood et al. 1997) and the rearingrecord of this species from papaya appears to represent ananomaly of no economic importance.

Fig. 2. Number of fruit fly species trapped as a function oftrapping intensity in each of the nine provinces of the SolomonIslands. Two observations (near Y = 26; X = 2.0) fell closetogether, and appear as a single point.


Tabl

e 4

Frui

t flie

s re

ared

fro

m c

omm

erci

al p

lant

s in

the

Solo

mon

Isl

ands

199

4–19

98

Plan

t spe

cies

Plan

t fam

ilyC

omm

on n

ame

or

de

scri

ptor

sM

atur

ityN

o. s

ampl

esN

o. f

ruits

Wei

ght (

g)Sp

ecie

s%

pos

itive

sa

mpl

esN

o. f

ruit

flies

No.

flie

s/ k

g fr

uit

Ach

ras

sapo

ta L

.Sa

pota

ceae

Sapo

dilla

–6

5225

74B

. fra

uenf

eldi

3324

9.3

Ana

card

ium

occ

iden

tale

L.

Ana

card

iace

aeC

ashe

w n

utw

f an

d p

429

1019

nil

nana

0.0

Ana

nus

com

osus

L. (

Mer

r.)B

rom

elia

ceae

Pine

appl

er

55

2300

nil

nana

0.0

Ann

ona

mur

icat

a L

.A

nnon

acea

eSo

urso

pw

f21

3124

674

B. f

raue

nfel

di33

481.

9A

nnon

a m

uric

ata

L.

Ann

onac

eae

Sour

sop

p19

2617

065

B. f

raue

nfel

di36

129

7.6

Ann

ona

squa

mos

a L

.A

nnon

acea

eSw

eets

opp

25

2440

nil

nana

0.0

Are

ca c

atec

hu L

.A

reca

ceae

Bet

el n

utr

15

250

nil

nana

0.0

Are

ca s

p.A

reca

ceae

Wild

bet

el n

utp

218

012

48ni

lna

na0.

0A

rtoc

arpu

s al

tili

s (P

ark.

) Fo

sb.

Mor

acea

eB

read

frui

tw

f77

284

1491

03B

. um

bros

a18

533

3.6

Art

ocar

pus

alti

lis

(Par

k.)

Fosb

.M

orac

eae

Bre

adfr

uit

p17 17

29 2919

055

1905

5B

. um

bros

a B

. fra

uenf

eldi

41 654

0 1028

.3 0.5

Art

ocar

pus

alti

lis

(Par

k.)

Fosb

.M

orac

eae

Bre

adfr

uit

wf

fl (m

ale)

213

317

nil

nana

0.0

Art

ocar

pus

hete

roph

yllu

s L

amk.

Mor

acea

eJa

ckfr

uit

wf

810

1163

1ni

lna

na0.

0A

rtoc

arpu

s he

tero

phyl

lus

Lam

k.M

orac

eae

Jack

frui

tp

5 521 21

9847

9847

B. u

mbr

osa

B. f

raue

nfel

di20 20

7 20.

70.

2A

rtoc

arpu

s od

oura

tiss

umM

orac

eae

Mam

ey s

apot

ew

f1

125

0ni

lna

na0.

0A

verr

hoa

cara

mbo

la L

.A

verr

hoac

eae

Car

ambo

law

f30

403

3159

2B

. fra

uenf

eldi

1315

0.5

Ave

rrho

a ca

ram

bola

L.

Ave

rrho

acea

eC

aram

bola

p36

269

2210

0B

. fra

uenf

eldi

1139

1.8

Bar

ring

toni

a as

iati

ca (

L.)

Lec

ythi

dace

aeV

utu

fl1

750

nil

nana

0.0

Bar

ring

toni

a as

iati

ca (

L.)

Lec

ythi

dace

aeV

utu

p an

d w

f7

2854

50ni

lna

na0.

0B

arri

ngto

nia

edul

is S

eem

.L

ecyt

hida

ceae

Cut

nut

wf

441

1800

B. f

raue

nfel

di25

10.

6B

arri

ngto

nia

edul

is S

eem

.L

ecyt

hida

ceae

Cut

nut

p12

135

5340

nil

nana

0.0

Bar

ring

toni

a ra

cem

osa

(L.)

Spr

eng.

Lec

ythi

dace

aep

19; w

f (1

)20

421

1012

6ni

lna

na0.

0B

arri

ngto

nia

sp.

Lec

ythi

dace

aeB

onga

ulu

(sha

de tr

ee)

g1

615

0ni

lna

na0.

0B

rass

ica

sp.

Cru

cife

rae

‘Sal

adia

’m

1on

e st

alk

nrni

lna

nana

Can

ariu

m in

dicu

m L

.B

urse

race

aeN

gali

nut

wf

1011

629

14ni

lna

na0.

0C

anar

ium

indi

cum

L.

Bur

sera

ceae

Nga

li nu

tp

877

1814

nil

nana

0.0

Can

ariu

m v

itie

nse

A. G

ray

Bur

sera

ceae

r2

8315

0ni

lna

na0.

0C

anar

ium

vul

gare

Lee

nh.

Bur

sera

ceae

Nga

li nu

tw

f an

d p

660

640

nil

nana

0.0

Can

ella

win

teri

ana

(L.)

Gae

rtn.

Can

ella

ceae

Wild

cin

nam

onm

186

50ni

lna

na0.

0C

apsi

cum

ann

uum

L.

Sola

nace

aeC

apsi

cum

p (1

0); w

f (3

)13

123

3744

nil

nana

0.0

Cap

sicu

m fr

utes

cens

L.

Sola

nace

aeC

hilli

p12

805

1710

nil

nana

0.0

Car

ica

papa

ya L

.C

aric

acea

ePa

paya

wf

1012

5957

B. f

raue

nfel

di25

488.

1C

aric

a pa

paya

L.

Car

icac

eae

Papa

yap

61 6110

310

361

736

6173

6B

. fra

uenf

eldi

B. c

alop

hyll

i†41 2

742 4

12.0 0.1

Chr

ysop

hyll

um c

aini

to L

.Sa

pota

ceae

Star

app

lep

36

1009

nil

0.0

Cit

rull

us la

natu

s (T

hunb

.) M

atsu

m.

& N

akai

Cuc

urbi

tace

aeW

ater

mel

onp

812

1077

0B

. cuc

urbi

tae

1342

3.9

Cit

rus

aura

ntif

olia

(C

hris

tm.)

Sw

ingl

eR

utac

eae

Lim

ew

f27

377

1515

2ni

lna

na0.

0

Cit

rus

aura

ntif

olia

(C

hris

tm.)

Sw

ingl

eR

utac

eae

Lim

ep

1628

499

69ni

lna

na0.

0

Cit

rus

aura

ntiu

m L

.R

utac

eae

Sour

ora

nge

wf

949

3079

B. f

raue

nfel

di11

10.

3C

itru

s au

rant

ium

L.

Rut

acea

eSo

ur o

rang

ep

852

4710

nil

nana

0.0

Cit

rus

lim

etta

Ris

soR

utac

eae

Swee

t lim

em

12

900

nil

nana

0.0

Cit

rus

lim

on B

urm

an f

.R

utac

eae

Lem

ons

wf

910

511

377

nil

nana

0.0


Tabl

e 4

Con

tinu

ed

Plan

t spe

cies

Plan

t fam

ilyC

omm

on n

ame

or

de

scri

ptor

sM

atur

ityN

o. s

ampl

esN

o. f

ruits

Wei

ght (

g)Sp

ecie

s%

pos

itive

sa

mpl

esN

o. f

ruit

flies

No.

flie

s/ k

g fr

uit

Cit

rus

aura

ntiu

m L

.R

utac

eae

Sour

ora

nge

p8

5247

10ni

lna

na0.

0C

itru

s li

met

ta R

isso

Rut

acea

eSw

eet l

ime

m1

290

0ni

lna

na0.

0C

itru

s li

mon

Bur

man

f.

Rut

acea

eL

emon

wf

910

511

377

nil

nana

0.0

Cit

rus

lim

on B

urm

an f

.R

utac

eae

Lem

onp

974

5471

nil

nana

0.0

Cit

rus

max

ima

(Bur

man

) M

err.

Rut

acea

ePo

mel

ow

f14

3116

547

nil

nana

0.0

Cit

rus

max

ima

(Bur

man

) M

err.

Rut

acea

ePo

mel

or

1019

1675

8B

. fra

uenf

eldi

1018

1.1

Cit

rus

reti

cula

ta B

lanc

oR

utac

eae

Man

dari

nw

f8

4363

84ni

lna

na0.

0C

itru

s re

ticu

lata

Bla

nco

Rut

acea

eM

anda

rin

p2

1414

69ni

lna

na0.

0C

itru

s si

nens

is (

L.)

Osb

eck

Rut

acea

eO

rang

ew

f7

2527

77ni

lna

na0.

0C

itru

s si

nens

is (

L.)

Osb

eck

Rut

acea

eO

rang

er

522

3900

nil

nana

0.0

Cit

rus

sp.

Rut

acea

eTa

ngel

o (m

anda

rin

grap

efru

it cr

oss)

wf

12

228

nil

nana

0.0

Cit

rus

sp.

Rut

acea

eC

itrus

(or

ange

co

lour

)w

f3

1217

21B

. fra

uenf

eldi

332

1.2

Cit

rus

sp.‡

Rut

acea

ep

754

4233

B. f

raue

nfel

di14

20.

5C

itru

s x

para

disi

Mac

fad.

Rut

acea

eG

rape

frui

tw

f12

3311

841

B. f

raue

nfel

di8

191.

6C

itru

s x

para

disi

Mac

fad.

Rut

acea

eG

rape

frui

tp

411

6271

nil

nana

0.0

Cof

fea

arab

ica

L.

Rub

iace

aeC

offe

er

223

233

0ni

lna

na0.

0C

offe

a sp

.R

ubia

ceae

Cof

fee

r9

2251

2571

nil

nana

0.0

Cra

taev

a sp

ecio

saun

know

nA

fuk

wf

and

m2

917

23ni

lna

na0.

0C

ucum

is m

elo

L.

Cuc

urbi

tace

aeR

ock

mel

onr

and

wf

512

1731

6ni

lna

na0.

0C

ucum

is s

ativ

us L

.C

ucur

bita

ceae

Cuc

umbe

rp

16 1661 61

1623

016

230

B. c

ucur

bita

e D

. sol

omon

ensi

s6 6

103 7

6.3

0.4

Cuc

urbi

ta p

epo

L.

var.

med

ullo

sa A

lef.

Cuc

urbi

tace

aePu

mpk

inp

(10)

; wf

(1)

1127

1374

5D

. sol

omon

ensi

s9

402.

9

Dio

spyr

os d

igyn

a Ja

cq.

Ebe

nace

aeB

lack

sap

ote

wf

38

454

nil

nana

0.0

Dio

spyr

os d

igyn

a Ja

cq.

Ebe

nace

aeB

lack

sap

ote

p5

875

6B

. fra

uenf

eldi

2011

14.6

Dio

spyr

os e

benu

m J

. Kön

igE

bena

ceae

Ebo

nyp

218

80B

. fra

uenf

eldi

5033

412.

5D

iosp

yros

kal

ei

Ebe

nace

ae–

r1

1431

nil

nana

0.0

Dio

spyr

os s

p.E

bena

ceae

–p

422

895

0ni

lna

na0.

0E

laei

s gu

inee

nsis

Jac

q.A

reca

ceae

Oil

palm

r an

d w

f6

179

1528

nil

nana

0.0

Eug

enia

sp.

Myr

tace

ae–

r1

123

250

nil

nana

0.0

Fla

cour

tia

iner

mis

Rox

b.Fl

acou

rtia

ceae

Lov

i-lo

viw

f3

121

715

nil

nana

0.0

Fla

cour

tia

iner

mis

Rox

b.Fl

acou

rtia

ceae

Lov

i-lo

vip

1343

825

70ni

lna

na0.

0F

ortu

nell

a ja

poni

ca (

Thu

nb.)

Sw

ingl

eR

utac

eae

Cum

quat

wf

339

800

B. f

raue

nfel

di33

33.

8

For

tune

lla

japo

nica

(T

hunb

.)

Swin

gle

Rut

acea

eC

umqu

atp

410

119

40ni

lna

na0.

0

Gar

cini

a m

ango

stan

a L

.C

lusi

acea

eM

ango

stee

np

226

1600

nil

nana

0.0

Gar

cini

a sp

.C

lusi

acea

eY

ello

w m

ango

stee

nw

f an

d m

232

328

nil

nana

0.0

Gar

cini

a sp

.C

lusi

acea

e(n

ativ

e tr

ee)

p4

2121

10ni

lna

0.0

Inoc

arpu

s fa

gife

r (P

arki

nson

) Fo

sb.

Faba

ceae

Poly

nesi

an

ches

tnut

wf

8 814 14

888

888

B. f

raue

nfel

di

B. m

oluc

cens

is21 13

255 2

287.

22.

3In

ocar

pus

fagi

fer

(Par

kins

on)

Fosb

.Fa

bace

aePo

lyne

sian

ch

estn

utp

1050

2123

B. m

oluc

cens

is10

104.

7

Lyc

oper

sico

n es

cule

ntum

Mill

erSo

lana

ceae

Tom

ato

wf

433

1350

nil

nana

0.0


Tabl

e 4

Con

tinu

ed

Plan

t spe

cies

Plan

t fam

ilyC

omm

on n

ame

or

de

scri

ptor

sM

atur

ityN

o. s

ampl

esN

o. f

ruits

Wei

ght (

g)Sp

ecie

s%

pos

itive

sa

mpl

esN

o. f

ruit

flies

No.

flie

s/kg

fr

uit

Lyc

oper

sico

n es

cule

ntum

Mill

erSo

lana

ceae

Tom

ato

wf

433

1350

nil

nana

0.0

Lyc

oper

sico

n es

cule

ntum

Mill

erSo

lana

ceae

Tom

ato

p23

293

9005

nil

nana

0.0

Mal

pigh

ia g

labr

a L

.M

alpi

ghia

ceae

Ace

rola

wf

255

400

nil

nana

0.0

Mal

pigh

ia g

labr

a L

.M

alpi

ghia

ceae

Ace

rola

r12

849

3429

nil

nana

0.0

Man

gife

ra in

dica

L.

Ana

card

iace

aeM

ango

wf

3942

575

770

B. f

raue

nfel

di67

1027

13.6

Man

gife

ra in

dica

L.

Ana

card

iace

aeM

ango

p8

1628

19B

. fra

uenf

eldi

5070

24.8

Man

gife

ra m

inor

Bl.

Ana

card

iace

aeSm

all m

ango

wf

611

577

00B

. fra

uenf

eldi

5050

6.5

Man

gife

ra m

inor

Bl.

Ana

card

iace

aeSm

all m

ango

r1

510

00ni

lna

na0.

0M

angi

fera

sp.

Ana

card

iace

ae–

wf

453

3508

B. f

raue

nfel

di50

125

35.6

Man

gife

ra s

p.A

naca

rdia

ceae

Wild

man

gor

12

145

nil

nana

0.0

Man

ihot

esc

ulen

ta C

rant

zE

upho

rbia

ceae

Cas

sava

p4

196

1090

nil

nana

0.0

Man

ihot

sp.

Eup

horb

iace

ae–

g1

1815

0ni

lna

na0.

0M

usa

x pa

radi

siac

a L

.M

usac

eae

Ban

ana

wf

129

2400

nil

nana

0.0

Mus

a x

para

disi

aca

L.

Mus

acea

eB

anan

ap

1311

381

10ni

lna

na0.

0N

ephe

lium

lapp

aceu

m L

.Sa

pind

acea

eR

ambu

tan

wf

17

200

nil

nana

0.0

Nep

heli

um la

ppac

eum

L.

Sapi

ndac

eae

Ram

buta

np

610

013

42ni

lna

na0.

0P

assi

flor

a ed

ulis

Sim

sPa

ssifl

orac

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Pass

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m1

450

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a am

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Mill

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aura

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wf

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111

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ceae

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251.

9P

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inna

ta F

orst

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a fr

uit

wf

631

736

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3310

414

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etia

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For

st. f

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14

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ria

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ito

(Rui

z &

Pav

on)

Sapo

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aeA

biu

wf

and

g2

540

0ni

lna

na0.

0P

oute

ria

sp.

Sapo

tace

aeA

biu

rela

tive

m1

457

5ni

lna

na0.

0P

sidi

um g

uaja

va L

.M

yrta

ceae

Gua

vaw

f30

219

3038

4B

. fra

uenf

eldi

6711

1836

.8P

sidi

um g

uaja

va L

.M

yrta

ceae

Gua

vap

6843

855

684

B. f

raue

nfel

di56

1665

29.9

Sola

num

mel

onge

na L

.So

lana

ceae

Egg

plan

tr

and

wf

1154

6820

nil

nana

0.0

Sola

num

sp.

Sola

nace

aeSm

all e

gg-s

hape

d fr

uit

r1

142

nil

nana

0.0

Sola

num

torv

um S

w.

Sola

nace

aeD

evil’

s-fig

fl1

3850

nil

nana

0.0

Sola

num

torv

um S

w.

Sola

nace

aeD

evil’

s-fig

p15

1765

2239

nil

nana

0.0

Syns

epal

um d

ulci

ficu

m

Schu

mac

her

& T

honn

.) D

anie

llSa

pota

ceae

Mir

acle

fru

itr

133

40ni

lna

na0.

0

Syzy

gium

mal

acce

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(L.)

Mer

r. &

Per

ryM

yrta

ceae

Mal

ayan

app

lew

f23

530

8823

B. f

raue

nfel

di61

878

99.5

Syzy

gium

mal

acce

nse

(L.)

Mer

r. &

Per

ryM

yrta

ceae

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ayan

app

lep

1328

522

76B

. fra

uenf

eldi

6228

012

3.0

The

obro

ma

caca

o L

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ercu

liace

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pod

sr

1333

1091

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lna

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rich

osan

thes

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ina

L.

Cuc

urbi

tace

aeSn

ake

gour

dw

f3 3

12 1248

5048

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. sol

omon

ensi

s B

. cuc

urbi

tae

33 3312 96

2.5

19.8

Tri

chos

anth

es c

ucum

erin

a L

.C

ucur

bita

ceae

Snak

e go

urd

p26 26 26

174

174

174

5069

850

698

5069

8

D. s

olom

onen

sis

B. c

ucur

bita

e B

. fra

uenf

eldi

38 8 4

275 64 13

5.4

1.3

0.3

Vig

na m

arin

a (B

urm

. f.)

Mer

r.Fa

bace

ae–

fl1

264

50ni

lna

na0.

0V

igna

mar

ina

(Bur

m. f

.) M

err.

Faba

ceae

–p

533

232

30ni

lna

na0.

0V

igna

ses

quip

edal

is (

L.)

Fru

hw.

Faba

ceae

Lon

g be

anp

350

490

nil

nana

0.0

–, in

form

atio

n no

t ava

ilabl

e; fl

, flow

er; g

, gre

en; m

, mat

ure;

na,

not

app

licab

le; n

r, no

t rec

orde

d; p

, pic

ked;

r, r

ipe;

wf,

win

dfal

l.

†Ano

mal

ous

reco

rd; ‡

sam

ple

incl

uded

sw

eet f

ruits

that

look

ed s

imila

r to

lim

es.


Tabl

e 5

Frui

t flie

s re

ared

fro

m n

on-c

omm

erci

al p

lant

s in

the

Solo

mon

Isl

ands

199

4–19

98

Plan

t spe

cies

Plan

t fam

ilyC

omm

on n

ame

or

desc

ript

ors

Mat

urity

†N

o.

sam

ples

No.

fr

uits

Wei

ght (

g)Sp

ecie

s%

pos

itive

sa

mpl

esTo

tal n

o.

frui

t flie

sN

o. fl

ies/

kg

fru

it

Alp

inia

pur

pura

ta (

Vie

ill.)

Sch

um.

Zin

gibe

race

aeR

ed g

inge

rp

2243

639

01B

. pha

ea4.

51

0.3

Bro

usso

neti

a pa

pyri

fera

L. (

Ven

t.)M

orac

eae

Pape

r m

ulbe

rry

p (1

7); w

f (1

)18

483

4604

B. f

raue

nfel

di6

20.

4B

urck

ella

sp.

Sapo

tace

aeG

ono

wf

19

60B

. dec

uman

a10

08

133.

3C

alop

hyll

um in

ophy

llum

L.

Clu

siac

eae

Koi

low

f an

d p

wf

and

p47 47

1160

1160

2230

322

303

B. c

alop

hyll

i B

. fra

uenf

eldi

19 217

6 137.

90.

6C

alop

hyll

um k

ajew

skii

A.C

. Sm

.C

lusi

acea

eK

oilo

wf

and

pw

f an

d p

4 479 79

3706

3706

B. c

alop

hyll

i B

. fra

uenf

eldi

25 257 5

1.9

1.3

Cer

bera

man

ghas

L.

Apo

cyna

ceae

Soto

p an

d w

f14

235

1020

0B

. fra

uenf

eldi

1410

810

.6C

occi

nea

gran

dis

(L.)

Voi

gtC

ucur

bita

ceae

Scar

let i

vy g

ourd

p11

275

3990

B. c

ucur

bita

e18

4411

.0C

occi

nea

gran

dis

(L.)

Voi

gtC

ucur

bita

ceae

Scar

let i

vy g

ourd

pna

nrnr

B. s

imul

ata

na1

naF

icus

sp.

†r

5395

66B

. fra

uenf

eldi

24

0.4

Gne

tum

gne

mon

L.

Gne

tace

aeK

ing

tree

wf

and

p2

7527

0B

. pen

efur

va10

019

371

4.8

Gue

ttar

da s

peci

osa

L.

Rub

iace

aew

f an

d p

462

586

B. f

raue

nfel

di25

11.

7N

aucl

ea s

p.N

aucl

eace

aew

fw

f2 2

76 7635

5435

54B

. fra

uenf

eldi

B

. nau

clea

e50 100

1 740.

320

.8P

olys

cias

sp.

Ara

liace

aep

1418

0415

36B

. um

bros

a‡7

10.

7Sc

aevo

la ta

ccad

a (G

aert

n.)

Rox

b.G

oode

niac

eae

p22

4035

2808

B. f

raue

nfel

di5

10.

4Sp

ondi

as c

ythe

rea

Sonn

.A

naca

rdia

ceae

Tevi

wf

1531

216

550

B. f

raue

nfel

di13

271.

6Sp

ondi

as c

ythe

rea

Sonn

.A

naca

rdia

ceae

Tevi

wf

1531

216

550

B. h

asti

geri

na80

158

9.5

Ter

min

alia

cat

appa

L.

Com

bret

acea

ePa

cific

alm

ond

wf

3011

0025

779

B. f

raue

nfel

di67

3032

117.

6T

erm

inal

ia c

atap

pa L

.C

ombr

etac

eae

Paci

fic a

lmon

dp

998

2189

B. f

raue

nfel

di33

137

62.6

Ter

min

alia

sp.

Com

bret

acea

ew

f6

286

3699

B. f

raue

nfel

di67

5715

.4T

erm

inal

ia w

hitm

orei

Coo

deC

ombr

etac

eae

wf

428

511

03B

. fra

uenf

eldi

7527

24.5

Ter

min

alia

whi

tmor

ei C

oode

Com

bret

acea

ep

316

269

6B

. fra

uenf

eldi

33nr

naU

nide

ntifi

edN

ut (

2.5

cm d

iam

.)w

f1

634

B. f

raue

nfel

di10

08

235.

3U

nide

ntifi

edPe

ncil

ceda

rr

126

72B

. fra

uenf

eldi

100

1115

2.8

Uni

dent

ified

Red

rou

nd f

ruits

wf

133

144

B. r

edun

ca10

03

20.8

Uni

dent

ified

, Gne

tum

gne

mon

?Sm

all r

ed f

ruit

wf

145

104

B. p

enef

urva

100

7168

2.7

na, n

ot a

pplic

able

; nr,

not r

ecor

ded;

p, p

icke

d; r,

rip

e; w

f, w

indf

all.

†Pro

babl

y F

icus

cop

iosa

; ‡an

omal

ous

reco

rd.


Bactrocera frauenfeldi was the most important pestinfesting commercial crops and the most common fruitfly in cuelure traps. The range of B. frauenfeldi includes:(i) Palau; (ii) Federated States of Micronesia; (iii) Nauru;(iv) the Marshall and Gilbert Islands; (v) the SolomonIslands; (vi) Papua New Guinea; and, since 1974, (vii) north-ern Queensland (White & Elson-Harris 1992; Leblanc1997). Bactrocera frauenfeldi is a very common specieswherever it is found (Drew 1982b; Leblanc 1997). In theFederated States of Micronesia (FSM), where B. frauenfeldiis the only fruit fly species present, it has been reared from31 plant species (Leblanc 1997). The host range reportedfor B. frauenfeldi in the present study was similar to thehost range reported for FSM. However, in the SolomonIslands, B. frauenfeldi was reared less frequently frombreadfruit samples (6% in the present study vs. 37% inFSM) (Leblanc & Allwood 1997). Bactrocera umbrosa wasreared from 41% of breadfruit samples in the SolomonIslands. It would appear that B. umbrosa, a fruit fly specialiston Artocarpus spp., is able to out-compete B. frauenfeldi onbreadfruit in the Solomon Islands. The record of B. umbrosafrom Polyscias sp. is an anomalous record requiring con-firmation. Polyscias is not in the same plant family asbreadfruit and jackfruit, which are the usual hosts for this flyspecies.

In general, given equal land areas, we should expectmore species diversity on islands or island groups closer toPapua New Guinea, which has a more diverse fruit flyfauna of at least 173 described species (Drew & Romig1997) and a much larger land area than the SolomonIslands. Western Province, closest to Papua New Guinea,includes several large islands (Kolombangara and NewGeorgia) and has a total land area of 5279 km2. We trapped26 fruit fly species from this province, but 31 species offruit flies from Guadalcanal, with a similar land area(5336 km2). Differences in trapping intensity are the prob-able explanation for this result as the sampling effort was10 times greater on Guadalcanal (1092 trap collections)than in Western Province (101 trap collections) (Table 1).This explanation is also supported by the significant regres-sion resulting when the number of fruit fly species detectedin each province is plotted against the number of trapsample collections made (Fig. 2).

Combining data from all sources, 49 species of fruitflies are reported to be present in the Solomon Islands(Table 3). However, the true number of species is probablyconsiderably greater. It is estimated that 10% of dacinefruit flies in the Pacific region are not attracted to malelures (Allwood 1997). Given that we were able to deter-mine host associations for only 13 of the 49 species of fruitflies in the Solomon Islands (Table 3), we can assume thatour fruit collections were inefficient in collecting speciesthat are not attracted to male lures. The majority of fruitcollections were made at lower elevations in areas acces-sible to vehicles. Presumably, a productive method fordocumenting additional host associations would be tomake fruit collections at higher elevations in remote areas,

where introduced plants are less abundant. Of the 49species listed in Table 3, five are known to be present inthe Solomon Islands, only because they were found in oneor two trap samples collected as part of the present study.These species could have been missed altogether had weused a slightly different placement of traps. Six specieslisted in Table 3 were previously collected in traps in theSolomon Islands, yet were not detected during this study,which was generally the most intensive trapping in theSolomon Islands to date. Collectively, this informationsuggests that the true number of fruit fly species present inthe Solomon Islands is significantly larger than reportedherein. However, our results clearly show that relativelyfew fruit fly species present in the Solomon Islands are ofeconomic importance. This emphasises the need for effec-tive quarantine measures that exclude exotic fruit fly pestsand thereby protect potential markets of high-value fruitsand vegetable exports.

ACKNOWLEDGEMENTS

This work was funded by the United Nations DevelopmentProgramme, AusAID, the Food and Agriculture Organisationof the United Nations, the Australian Centre for InternationalAgricultural Research and the New Zealand Government.We thank the many Extension, Research and QuarantineOfficers who assisted in this work. We give special thanks toRichard Wiley, formerly a United Nations volunteer in theSolomon Islands, who managed the sampling program during1994–1995. We acknowledge the inspiration of the lateJeffrey Varuia (Director of Extension), and give specialthanks to Ezekiel Walaodo (Under Secretary for Agricul-ture), Ruth Liloqula (Director of Research), Cameron Eta(Director of Quarantine), Michael Oliouou (Station Managerof Dodo Creek Research Station), Dodo Creek ResearchStation assistants Prudence Raveli and Eddie Valenga,Myknee Sirikolo and his assistants at the National Herbarium,Peace Corps volunteers Pam Newton and Tara Goldsmith,and Agricultural Extension Officers Ambrose Siau, MichaelHoota, Robert Ramo, Selwyn, and Jasper. We thank PeterFollett and Roger Vargas (U.S. Pacific Basin AgriculturalResearch Center, Hilo, Hawaii) for their critical reviews ofan earlier draft of this manuscript.

REFERENCES

Allwood AJ. 1997. Responses of fruit flies (Family Tephritidae) to malelures in seven Pacific island countries. In: Management of FruitFlies in the Pacific, a Regional Symposium, Nadi, Fiji, 28–31October, 1996, ACIAR Proceedings No. 76 (eds AJ Allwood & RAIDrew) pp. 111–114. Australian Centre for International Agricul-tural Research, Canberra.

Allwood AJ, Tumukon T, Tau D & Kassim A. 1997. Fruit fly fauna inVanuatu. In: Management of Fruit Flies in the Pacific, a RegionalSymposium, Nadi, Fiji, 28–31 October, 1996, ACIAR ProceedingsNo. 76 (eds AJ Allwood & RAI Drew), pp. 77–80. AustralianCentre for International Agricultural Research, Canberra.


Amice R & Sales F. 1997. Fruit fly fauna in New Caledonia. In:Management of Fruit Flies in the Pacific, a Regional Symposium.Nadi, Fiji, 28–31 October 1996, ACIAR Proceedings No. 76 (edsAJ Allwood & RAI Drew), pp. 68–76. Australian Centre for Inter-national Agricultural Research, Canberra.

Drew RAI. 1982a. Fruit fly collecting. In: Economic Fruit Flies of theSouth Pacific Region (eds RAI Drew, GHS Hooper & MA Bateman),pp. 129–139. Queensland Department of Primary Industries,Brisbane.

Drew RAI. 1982b. Taxonomy. In: Economic Fruit Flies of the SouthPacific Region (eds RAI Drew, GHS Hooper & MA Bateman),pp. 1–97. Queensland Department of Primary Industries, Brisbane.

Drew RAI & Romig MC. 1997. Overview – Tephritidae in the Pacificand Southeast Asia. In: Management of Fruit Flies in the Pacific, aRegional Symposium, Nadi, Fiji, 28–31 October 1996, ACIARProceedings No. 76 (eds AJ Allwood & RAI Drew) pp. 46–53.Australian Centre for International Agricultural Research,Canberra.

Drew RAI & Romig MC. 2001. The fruit fly fauna (Diptera: Tephriti-dae: Dacinae) of Bougainville, the Solomon Islands and Vanuatu.Australian Journal of Entomology 40, 113–150.

Hollingsworth RG, Tsatsia F & Vagalo M. 1997. Biology of the melonfly, with special reference to the Solomon Islands. In: Managementof Fruit Flies in the Pacific, a Regional Symposium, Nadi, Fiji,28–31 October 1996, ACIAR Proceedings No. 76 (eds AJ Allwood& RAI Drew), pp. 140–144. Australian Centre for InternationalAgricultural Research, Canberra.

Leblanc L. 1997. Fruit fly fauna in Federated States of Micronesia,Guam, Palau, Kiribati, Northern Marianas and Marshall Islands. In:Management of Fruit Flies in the Pacific, a Regional Symposium,Nadi, Fiji, 28–31 October 1996, ACIAR Proceedings No. 76 (edsAJ Allwood & RAI Drew), pp. 64–67. Australian Centre for Inter-national Agricultural Research, Canberra.

Leblanc L & Allwood A. 1997. Mango Fruit Fly. Pest Leaflet AACR2,ISMN 982–203–540–3. South Pacific Commission, Suva.

White IM & Elson-Harris MM. 1992. Fruit Flies of Economic Sig-nificance: Their Identification and Bionomics. CAB International,Wallingford, UK.

Accepted for publication 9 November 2002.

Documents

Host plants and relative abundance of fruit fly (Diptera: Tephritidae) species in the Solomon Islands