Abstract: Over a period of 18 months the bacteria associated with approximately 70 adult flies of four Dacus species were isolated and identified. The flies were D. tryoni (Froggatt) and D. neohumeralis Hardy from guava (Psidium guajava L.), mulberry (Morus nigra L.) and peach [Prunus persica (L.) Batsch], D. cacuminatus (Hering) from wild tobacco (Solanum mauritianum Scop.), and D. musae (Tryon) from banana (Musa paradisiaca L.), and were collected in the field when these host plants were fruiting. All flies examined were surface-sterilized prior to aseptic dissection in which crop and mid-gut (stomach) or oesophageal bulbs were removed for culturing. Bacteria were also isolated from faeces of field-collected flies, as well as from host fruit surfaces, oviposition sites and larvae-infested tissue in host fruit. The predominant bacteria found in the alimentary tract of flies and in associated fruit specimens were members of the family Enterobacteriaceae. Klebsiella oxytoca, Erwinia herbicola and Enterobacter cloacae were the most frequently isolated species, with Serratia spp., Citrobacter jreundii, Proteus spp., Providencia rettgeri and Escherichia coli, being found less frequently. No one bacterial species was found to be consistently associated with anyone fly species. The bacterial species found most frequently in the alimentary tract were also found in large numbers on the surfaces of host fruit and in stung fruit.

Abstract: Late third instars of Mediterranean fruit fly, Ceratitis capitata (Wiedemann); melon fly, Dacus cucurbitae Coquillett; and oriental fruit fly, D. dorsalis Hendel, that had exited the media to pupate were exposed to five concentrations of Steinernema feltiae (=Neoaplectana carpocapsae) ranging from 500,000 to 5,000 per cup. Mean corrected percent mortalities 6 days after exposure ranged from 92 to 9% for Mediterranean fruit fly, 85 to 9% for the oriental fruit fly, and 86 to 0% for melon fly. Emerging Mediterranean fruit fly adults were marginally susceptible at 0.2% verified infection, and pupae in puparia were not susceptible to S. feltiae .

Abstract: Kinetics of thermal death and death rate curves for eggs and first instar Mediterranean fruit fly, Ceratitis capitata (Wiedemann); oriental fruit fly, Dacus dorsalis (Hendel); and melon fly, Dacus cucurbitae (Coquillett), were determined at temperatures between 42 and 48°C and for times of up to 50 min using a hot water-immersion technique. Both eggs and larvae of all three species showed mortality that was directly related to the severity of treatment and time of exposure. Larvae appeared more resistant to heat than eggs at a given temperature. Larval tolerance to heat was very similar for all species; Mediterranean fruit fly eggs appeared more tolerant to heat than those of either of the Dacus species. Eggs and larvae of all three species showed death rate curves characterized by a lag at lower temperatures followed by a more or less constant rate of death. At high temperatures, the curves appeared logarithmic. This information may be useful in determining suitability of heat treatments for disinfestation of commodities attacked by these insects.

Abstract: Exploration for parasitoids ofCeratitis capitata (Wiedemann) [Diptera: Tephritidae] was conducted in Cameroon and Togo and parasitoids collected were released in Costa Rica. Collections yielded large numbers ofOpius perproximus Silvestri,Biosteres caudatus Szepligeti, andB. caudatus auct. [Opiinae: Braconidae]. Other Opiines collected wereB. fullawayi (Silvestri),B. desideratus (Bridwell), and an undescribed species ofOpius. Parasitization of tephritids in coffee ranged from 10–56%, with an average 35% parasitism in a research plantation and 17% in a commercial plantation. Parasitism in fruits other than coffee was less than 5%. The most commonly reared tephritids from coffee wereTrirhithrum coffeae Bezzi andC. (Pterandrus) anonae Graham.C. capitata occurred in low frequency in coffee; and adults were rarely observed. Other rearings includedT. albonigrum (Enderlein),T. sp. nr.validum Bezzi,T. nigerrimum auct. nec. Bezzi,C. (Pterandrus) colae Silvestri,C. (Pterandrus) flexuosa (Walker),C. (Ceratalaspis) spp.cosyra (Walker) group,C. (Pardalaspis) sp.punctata (Wiedemann) group,C. (Ceratalaspis) giffardi Bezzi,Dacus (Dacus) bivittatus (Bigot),D. (Didacus) ciliatus Loew, andGymnodacus sp.

Abstract: Cuticular alkanes obtained from larvae and adults of six species of tephritid fruit flies, Anastrepha ludens, A. suspensa, Ceratitis capitata, C. rosa, Dacus cucurbitae, and D. dorsalis were analyzed by gas chromatography. The same four major alkanes were shown to be present by capillary GC-mass spectra in all Anastrepha and Ceratitis larvae. Profiles were obtained from individual larvae and adult specimens that showed statistical differences between species, whereas profiles of conspecific life forms including pupae of A. suspensa from different locations showed some similarities. Sexual dimorphism was not observed in alkanes extracted from adults. A novel series of alkadienes was found in all Anastrepha and Ceratitis but not in Dacus.

Abstract: Larvae of the olive fruit fly, Dacus oleae (Gmelin), developed on the trees in autumn, or were reared in the laboratory on olives picked in autumn and cold-stored until use. Forty-five to 67% of 14-day-old adult females were found with immature ovaries when maintained at 16:8 (L:D) and 26–27°C or 24°C (L):22°C (D) provided that the immaturestages had been reared at 12:12 (L:D) and 20°C (L): 18°C (D) or 16:8 (L:D) and 20°C (L):18°C (D). When the immature stages had been reared at 16:8 (L:D) and 26–27°C or 24°C (L): 22°C (D), the percentage of females with immature ovaries was low. It was also low when the adults were maintained at 12:12 (L:D) and 20°C (L): 18°C (D), 24°C (L) :22°C (D), or 26°C (L):24°C (D), irrespective of the conditions under which the immatures had been reared. The observed ovarian immaturity has the attributes of a facultative reproductive diapause.

Abstract: Plywood rectangles (15×20×0.4 cm) dipped in a 0.1% (a.i.) water solution of deltamethrin (Decis) for 15 min and baited with two dispensers, one containing a mixture of sex pheromones and another containing ammonium bicarbonate, a food attractant for both sexes, were used as traps at a density of approximately 1 trap/3 trees in a 30,000 olive orchard for the control of the olive fruit fly, Dacus oleae in the island of Crete, Greece in 1984. Mean fruit infestation at harvest time was 2.4% in the test orchard, compared to 0.7% in the nearby orchards protected by bait sprays. The total income loss in the test orchard due to D. oleae infestation is estimated at about Drs. 6 per tree. The present cost of this trapping method was comparable to or less than that of bait sprays, but it can be reduced significantly. The cost of bait sprays for 1984 was about Drs. 20 per tree, not including the ecological and toxicological consequences. Zusammenfassung Pilotversuche zur Bekampfung der Olivenfruchtfliege, Dacus oleae Gmel. (Dipt., Tephritidae) mit Duftstoff-Fallen Es wurden rechteckige Sperrholzplatten (15 × 20 cm) 15 min lang in 0,1 %ige wasserige Losung von Deltamethrin getaucht und mit 2 Dispensern: einer Sexualpheromon-Kombination sowie einem auf beide Geschlechter wirkenden Nahrungsduftstoff versehen. Eine Falle pro 3 Baume, insgesamt 10000 Stuck, wurden 1984 in einer Olivenplantage auf der Insel Kreta zur Bekampfung von D. oleae ausgebracht. Zur Erntezeit waren 2,4 % der Fruchte in der Testplantage gegenuber 0,7% in einer Nachbarplantage, die mit Kodersprays behandelt war, befallen. Der gesamte Einkommensverlust in der Testplantage wurde auf 6 Drachmen pro Baum berechnet. Die Kosten der Fallenbekampfung waren damit geringer als jene mit Kodersprays und konnen noch weiter reduziert werden. Die Kosten fur die Koderspruh-Behandlung betrugen 1984 etwa 20 Drs pro Baum. Weiterhin sind die okologischen und toxikologischen Nebenwirkungen dieses Verfahrens zu bedenken.

Abstract: Mass-trapping of male oriental fruit flies, Dacus dorsalis Hendel, with methyleugenol plus malathion at the rate of nine saturated fiberboard blocks per ha produced male population reductions >99% in a papaya orchard (63 ha). However, because the surrounding jungle was not trapped, fruit infestation rate was reduced only 48%.

Abstract: Distribution of the melon fly, Dacus cucurbitae Coquillett, was determined by trapping males at 330 sites throughout the island of Kauai. Melon flies were most numerous at coastal trap sites, particularly along the south and west coasts. The Waimea Valley site located on the southwest coast was the one with the highest trap catch. Lowest catches were made at the highest elevations at the center of the island. Trap catches declined sharply with increasing rainfall and increasing elevation. However, during the seasonal peak in abundance in late summer, a few flies were trapped in the higher elevations where no host plants were present. These flies were evidently migrating rather than breeding flies. Melon fly distribution was related to distribution of its host plants. Distribution of the fly was largely along coastal areas of the island where host plants were present in commercial and backyard gardens. The melon fly was also present in noncultivated areas where the wild host, Momordica balsamina L., was located along edges of fields and roadsides.

Abstract: Combined gas chromatography–mass spectrometric examination of the rectal gland secretions of a number of Dacus species (Diptera: Tephritidae) having pest status in Australasia, has revealed the presence of a range of spiroacetals.

Abstract: Two closely related allopatric species in the tryoni complex, Dacus (Bactrocera) aquilonis (May) and D. (Bactrocera) tryoni (Froggatt), are compared on the basis of morphology, cytology, electrophoresis of enzymes, mating and sterility tests, and chemical analyses of male pheromones, and are shown to be valid species. The species were found to be closely related, showing only small morphological differences in body color, male surstyli, ovipositors, and egg surfaces. Differences were found in isoelectric focusing of esterase and glutamate dehydrogenase enzymes. A Nei's similarity coefficient of 0.95 was calculated based on 30 loci in cellulose acetate gel electrophoresis. Small differences were found in minor components of male pheromones, but no differences were found in metaphase chromosomes and asymmetric isolation in mate-recognition and sterility tests. Validity of mate-recognition tests in the laboratory is discussed in view of elimination of components of the specific mate-recognition systems that are known to exist in field populations of Dacinae.

Abstract: Captures of females of 4 species of fruit flies on or in both coloured sticky traps and protein baited traps were reduced by synthetic male attractants Captures of female Dacus tryoni (Froggatt), Dacus neohumeralis Hardy and Dacus cacuminatus (Hering) were reduced by both cuelure and methyl eugenol, and female Ceratitis capitata (Weidemann) by Capilure® These effects were sufficient to overcome the normally attractive stimuli of colour and odours associated with yeast

Abstract: Fifty compounds related to benzyl acetate were evaluated quantitatively as attractants to the male oriental fruit fly (Dacus dorsalis) and the male melon fly (Dacus cucurbitae). Thienylmethyl acetate was nearly as attractive as benzyl acetate to both species, but cyclohexylmethyl acetate was completely unattractive, emphasizing the role of the planar aromatic ring in receptor interaction. Although benzyl acetate was equally attractive to both species, para substituents invariably reduced attraction to the oriental fruit fly. A number of derivatives, including p-hydroxy-, p-methoxy-, p-acetoxy-, and p-cyanobenzyl acetates were highly attractive to the melon fly. Selective fluorination indicated that the polarizability of the carbonyl carbon is important in receptor interaction with the melon fly but is not specifically involved in the oriental fruit fly. Attraction to the melon fly was lost with ortho, meta, or dimethoxy substitution of benzyl acetate, but the 3,4- and 2,5-dimethoxybenzyl acetates were attractive to the oriental fruit fly. These results are interpreted in terms of specific olfactory receptor interactions for the two species of fruit flies.

Abstract: Spatial pattern of distribution of the fruit flies caught in traps under the implementation of the male annihilation method (MA) and sterile insect technique (SIT) was analysed. As for MA applied to Dacus dorsalis, the index of dispersion of individuals, Iδ , and the density-contagiousness coefficient, β , in the frequency distribution of flies caught in traps were useful to predict a successful eradication. In SIT for D.cucurbitae, sterile flies released could be conveniently dispersed to local patches where wild flies were abundant. However, the correlation coefficient between the number of sterile flies and that of the wild flies caught in traps in the area where SIT was being implemented was often low. This observation suggests that the effect of SIT is not homogeneous among local patches. These facts suggest that the analysis of the spatial distribution of fruit flies in the target area of the eradication project is important to devise a strategy for the implementation of SIT and also for the evaluation and analyses of the eradication processes.

Abstract: The populations of native male adult oriental fruit flyDacus dorsalis (Hendel) and artocarpus fruit flyD. umbrosus (F.) in two selected site (BU and SD) were estimated weekly by the capture-recapture technique using live traps baited with methyl eugenol. In BU where many varieties of fruit trees were grown, the estimated population densities ofD. dorsalis were between 980 and 3100 male flies per ha between May and July, 1984. During the same period, in SD where there were fewer number and varieties of fruit trees, the estimated population densities were between 300 and 1000 flies per ha. The estimated population densities ofD. umbrosus over the same period were between 570 and 1290 flies per ha in BU; and between 5 and 95 flies per ha in SD.

Abstract: Nearly all females of a 32-year-old laboratory strain of Dacus cucurbitae Coquillett had mature eggs by 10 days of age. Most females of a wild strain had mature eggs by 20 days. Mating ability was reached at about the same adult age as ovarian maturity. Frequencies of wild male × laboratory female, the reciprocal, and wild male × wild female were all the same. Thus, no evidence for sexual isolation between the two strains was obtained in the laboratory. In outdoor cages, laboratory-reared flies tended to mate faster than wild flies, but differences in mating speed were not significant. In tests combining all types of flies, wild and laboratory males mated equally well with both kinds of females.

Abstract: 1. 1. Seven natural populations of Dacus dorsalis were analyzed for a dimeric esterase by means of horizontal starch-gel electrophoresis. 2. 2. The electrophoretic phenotypes were governed by nine codominant Est-D alleles. 3. 3. The commonest allele in all seven population samples was Est-D 100 which encoded an electrophoretic band with intermediate mobility. 4. 4. The distribution of EST-D phenotypes were in accordance with Hardy-Weinberg expectations. 5. 5. There was no geographic variation in the distribution of Est-D alleles.

Abstract: In spite of widespread application of poisonous bait sprays against Dacus oleae in Crete, populations of its parasites sometimes show high densities. Most important are the chalcid ectoparasites Eupelmus urozonus and Pnigalio mediterraneus and the braconid Opius concolor. Several efforts for biological control of D. oleae with O. concolor have been made in Greece. The most promising were inundative releases against the spring generation of D. oleae as well as releases within foci of D. oleae in summer. Introduced exotic parasitoids (Biosteres longicaudatus, Dirhinus giffardii and B. oophilus) failed to establish.

Abstract: Some Australian fruit flies—i.e., Queensland fruit fly, Dacus tryoni (Froggatt); lesser Queensland fruit fly, Dacus neohumeralis Hardy; solanum fly, Dacus cacuminatus (Hering); and Mediterranean fruit fly, Ceratitis capitata (Wiedemann)—attracted to Steiner traps died outside them. They either succumbed to the insecticide before entering or escaped before being overcome. In a normal trapping program, these flies would fall to the ground and be lost, leading to an observed catch sometimes substantially lower than the actual number of flies attracted. Choice of insecticide used in the trap had a marked effect on number of flies lost and, consequently, on total size of the catch. Dichlorvos was a more effective insecticide for use in traps than malathion, lindane, trichlorfon, or naled.

Abstract: ウリミバエの蛹を27°C, 30°C, 32°Cおよび34°Cの温度に置き,それから羽化した成虫について蛹期の高温の影響を調べた。1) BOLLER et al. (1981)の方法に準じて成虫の飛翔能力を測定したところ,処理温度が高くなるに従い飛翔できる成虫の割合が減少した。また,腹部が異常に大きくなったり,翅がちぢれた個体の割合が多くなった。2) 羽化率には27°C, 30°Cおよび32°C区間で有意差はなく,34°C区では他の区に対して有意に低下した。3) いずれの区も羽化後3日目ころから卵巣が発達しはじめ羽化後25日目には全温度区の全生存個体が完成卵をもった。34°C区のものが途中他の区に比べ発育がおくれる傾向があったが,蛹期温度のちがいによる卵巣発育への影響は顕著ではなかった。4) 27°Cと30°C区のものは同程度の交尾率であったが32°C区では半数以下,34°C区ではほとんど交尾せず,32°C, 34°Cおよびそれ以外の処理区間で有意差があった。また雄は雌よりも高温障害がでやすいことがわかった。5) 飛翔できない成虫は餌がとれない条件の下で羽化後2か月目の生存率は,27°C区では75%以上,30°C区では50%,32°C区で10%であったが34°Cになると羽化後5日目ですでに30%に低下した。

Abstract: The efficacy of mass trapping for the control of olive fruit fly, Dacus oleae was tested in seven different experiments conducted from 1980 to 1984. Sticky or insecticide traps baited with pheromones combined with food and/or colour attractants were used. Results showed that crop protection can be achieved by mass trapping only in cases where insect movement into the protected orchard from the surrounding area is excluded. Sticky traps can be effective in cases of low pest population densities if they are renewed at regular intervals to ensure high efficiency of the sticky surface. Insecticide-treated traps with appropriate attractant and insecticide concentrations to secure a full active life of a complete year can replace sticky traps with considerable reduction of cost and increase of effectiveness. In addition they can be used in a continuous mass-trapping system. Such a system would be operational throughout the year and is expected to be more effective than trapping during part of the year only. Experiments along this line are in progress during 1984.

Abstract: Since 1981, when synthetic sex pheromones of Dacus oleae became available, much effort has been made toward their use in the control of this pest. A brief review of background information pertaining to this subject is presented here. Attempts at practical use of D. oleae pheromones include: monitoring, mass trapping and mating disruption. Although definite correlation of pheromone trap catches and olive fruit infestation has been reported, pheromone traps are not used yet for monitoring wild populations. Mass trapping, after its 5-year development process, today shows good possibilities of success. Although mass trapping in its present form cannot replace current control practices, it is expected that improvement of trap efficiency and establishment of optimal trap densities will make this goal possible in the near future. Mating disruption is still at the preliminary stage, though some encouraging results have been reported.

Abstract: . When deprived of their preferred hosts for up to 16 days prior to behaviour assays, three relatively specialized tephritid flies, D. cacuminatus (Hering), D. cucumis French and D. jarvisi (Tryon), retain strong preferences for their particular hosts. Moreover, in the absence of the preferred hosts, D. cacuminatus, and to a lesser extent D. cucumis, will not accept fruits that are outside their normal host range. D. jarvisi readily accepts other fruits in the absence of its preferred host, Planchonia careya, but in common with the other two shows no increase in the number of eggs laid with increasing periods of deprivation. None of these species accumulate oocytes when deprived of fruits. In contrast, the highly polyphagous D. tryoni Frogg. lays more eggs and oviposits readily into a previously unacceptable fruit after 4 days without access to hosts. This change in behaviour is associated with a marked increase in the number of mature eggs carried by females. These results suggest an important difference between the generalist and more specialized species in the physiological control of oocyte maturation. In D. tryoni there appears to be no inhibition of oocyte development once the primary follicle has matured, whereas in the other species each ovariole contains no more than one mature egg. In D. tryoni, the change in behaviour which accompanies this increase in egg load, may influence its propensity to accept unusual fruits, and may help to explain its rapid acceptance of most cultivated fruits introduced to Australia.