Abstract: Behavioral responses of adult female oriental fruit flies, Dacus dorsalisHendel, to the odor of papayas from three ripeness classes were studied using a threechoice flight tunnel bioassay. Laboratoryreared flies were allowed to respond freely to any of three papaya odors (mature green, colorbreak to one-fourth ripe, and one-half to full ripe) emanating from identical (spherical) fruit models. Five behaviors were measured in assessing the fly's relative attraction to the odors (number of landings), arrestment (total fly seconds on sphere), fly-fly interactions on the fruit model (maximum and modal fly density), and acceptance for oviposition (total eggs laid). Females showed no significant difference in total fly landings based on all age classes combined. Significant differences were noted among age classes. Females spent more total time on the sphere and showed a higher maximum density and modal fly density to ripe fruit than to green fruit odors. Ovipositional acceptance of fruit models based on the total number of eggs laid in a sphere was greater in response to the ripefruit odor than to the other two odor classes. Olfactorystimulated behavioral responses of females to the odor of ripe papayas were significantly different from the other ripeness classes for all behaviors at 8 days postemergence and then declined in 11-day-old flies. Behavioral responses were greater during the afternoon than in the morning. Observations of wild oriental fruit flies to papayas in the field indicated a preference for residing on riper fruit. The results of this study are discussed with regard to the role of olfactory inputs generated by the odor of ripening fruit on female attraction and oviposition behavior resulting in infestation of papayas by oriental fruit fly.

Abstract: In frugivorous tephritids, the host use pattern of ovipositing females may be an important factor shaping the mating system (Prokopy, 1980; Burk, 1981). In monophagous species, males would be expected to establish territories at the oviposition site and allow females access to the substrate in return for mating (Hendrichs and Reyes, 1986). In polyphagous species, on the other hand, males would be unable to control access to oviposition sites, resulting in the evolution of nonresource-based mating systems. Leks [aggregations of males that females visit solely for the purpose of mating (Bradbury, 1981)] have, in fact, been described for several polyphagous species of tephritids (e.g., Tychsen, .1977; Kuba et al., 1984). Despite the apparent success of the \"Prokopy-Burk model,\" data for additional species are desirable to test its generality further. Here, we present field observations on the mating behavior of the oriental fruit fly, Dacus dorsalis Hendel. The species is a major agricultural pest throughout Asia and Hawaii, attacking the fruits of over 150 plant species (Christenson and Foote, 1960). Despite its economic importance, however, little information exists regarding the biology of the oriental fruit fly in natural environments. Several workers (e.g., Arakaki et al., 1984; Poramarcom, 1988) have investigated the mating behavior of D. dorsalis in the laboratory, and the following summary derives from these earlier studies. Decreasing light intensity stimulates sexual activities, and mating behavior is confined to the 2to 3-h period immediately preceding sunset. Sexually active males fan their wings very rapidly, producing a high-pitched buzzing sound. In conjunction with rear leg

Abstract: The identification of a species of Bactrocera (formerly Dacus) in Suriname in 1986 resulted in a survey to obtain information on the host plants of this fruit fly and its geographical distribution. During four years, 77 plant species were collected to obtain fruit flies infesting those fruits and Jackson traps were set to collect adults. Only one Bactrocera species and several Anastrepha species were reared from fruits. The Carambola fruit fly was found in 15 plant species and flies were trapped from the eastern border up to 56@* 30@? longitude west in the Coronie district; to the south up to the Brokopondo Lake and southwest isolated along the western border with Guyana.

Abstract: Abundance of oriental fruit fly, Dacus dorsalis Hendel, and associated parasitoids was determined in a commercial guava, Psidium guajava L., orchard by canopy fogging and fruit collections during 1988 and 1989. D. dorsalis populations reached a maximum of 2.6 adults per tree in 1988 and 1.4 adults per tree in 1989. Four parasitoid species were recovered from guava tree canopies; Biosteres arisanus (Sonan) was the most abundant species, followed by Diachasmimorpha longicaudata (Ashmead), Psyttalia incise (Silvestri), and Biosteres vandenboschi (Fullaway), respectively. D. dorsalis and parasitoids recovered from guava canopies exhibited different sex ratios from populations that emerged from fruit samples. Abundance of D. dorsalis and its parasitoids was correlated with the number of ripe fruit present in the orchard. Parasitoid abundance was correlated with D. dorsalis abundance in 1988. Diversity and abundance of parasitoids estimated from canopy fogging and fruit collections differed.

Abstract: Laboratory-reared and wild adults of the melon fly,Dacus cucurbitae Coquillett, were tested for response to cue-lure at various ages. Virgin laboratory (4, 6, 8, 10, 12, and 14 days old) and wild (10, 12, 14, 16, 18, 20, and 22 days old) flies were released into outdoor field cages and trapped from 0800 until 1600 hr. Response of males to cue-lure increased with age and corresponded with sexual maturity for each strain. Females of both strains were relatively nonresponsive to cue-lure. Failure to eradicate in past male annihilation programs againstD. cucurbitae may be explained in part by the fact that only older males, which may have already mated with gravid females, respond to cue-lure.

Abstract: A nine-component synthetic mixture was developed to replace protein hydrolysates as food bait for melon flies, Dacus cucurbitae Coquillett , based on likely breakdown products of protein fermentation and on nutritional considerations. The nine-component mixture was found to be as attractive as a standard hydrolyzed protein bait. Subsequent research showed that only four of the nine components were important. The four-component mixture, made up of ammonium bicarbonate, linolenic acid, putrescine, and pyrrolidine, was as effective as the standard food bait.

Abstract: Parasitization rates of eggs of oriental fruit fly, Dacus dorsalis Hendel, by Biosteres arisanus (Sonan), and larvae of melon fly, Dacus cucurbitae Coquillett. by Psytallia fletcheri (Silvestri) in mature green to fully ripe papaya fruits on trees and in fully ripe fruits on the ground was studied. Parasitization of oriental fruit fly eggs by B. arisanus was greater in fully ripe fruits than in one-quarter to half-ripe fruits on trees; B. arisanus never parasitized oriental fruit fly eggs in mature green to color-break fruits. No difference was observed in the density of emergent B. arisanus adults from oriental fruit fly pupae recovered from fully ripe fruits on trees and on the ground. Parasitization of melon fly larvae by P. fletcheri was observed in only one fully ripe, fallen fruit. Results in relation to the effect of host plants on the foraging behavior of adult parasitoids and to the biological control of oriental fruit fly and melon fly in an agricultural ecosystem were discussed.

Abstract: The spermatozoa of the 2 fruit fly species, Dacus oleae (Gmel.) and Drosophila melanogaster Meig. (Diptera), have been fixed in a glutaraldehyde-tannic acid mixture, followed by uranyl acetate postfixation, and the sperm tail studied by high resolution electron microscopy. Spermatozoa of both species were seen to possess a centriole containing 9 microtubular triplets. The centriolar A-, B- and C-subtubules have 13, 10 and 9 protofilaments, respectively. The outer subtubules (the C-subtubules) seem to be continuous with the accessory tubules of the main part of the tail. The accessory tubules and their intertubular material have a complex fine structure similar to that described in some other brachyceran flies. In the end piece of the sperm tail, the A-subtubules undergo degeneration, characterized by swelling and a loss of dynein arms and spokes. The tail region appears to be immotile, possibly to enable it better to stick to receptors on the egg micropyle.

Abstract: Responses of Melon fly, Dacus cucurbitae Coquillett, oriental fruit fly, Dacus dorsalis Hendel, and Mediterranean fruit fly, Ceratitis capitata (Wiedemann), to artificial oviposition bottles treated with various liquids derived from host juices or extracts and water was tested in a choice test device. Harvest of D. cucurbitae eggs was 89.4% higher from oviposition bottles that contained the juice of pumpkin, Cucurbita maxima Duchesne, than from bottles with the juice of tomato, Lycopersicon esculentum Miller, the standard oviposition stimulant. Harvest of D. dorsalis eggs was 55.2% higher from oviposition bottles that contained juice of orange, Citrus sinensis (L.) Osbeck, than from bottles with juice of guava, Psidium guajava L., the standard oviposition stimulant. Harvest of C. capitata eggs from oviposition bottles that contained an extract of coffee, Coffea arabica L., was equal to those with the standard oviposition stimulant (water). Results indicate that host fruit juices with minimal commercial processing and without additives were the best oviposition stimulants. Findings are discussed in the context of oviposition stimulant evaluation procedures and mass production of tephritid fruit flies.

Abstract: Green olives of three varieties were sprayed in the laboratory with 1% copper hydroxide plus 0.1% Agral-90 in tap water. A few hours and 1 and 2 days later, the treated olives were offered for oviposition to 15–20-day-old females of Dacus oleae (Gmelin) (Diptera: Tephritidae), in two-choice and no-choice tests lasting 3 h. In all cases, copper hydroxide had a strong oviposition-deterring effect, while Agral-90 alone was ineffective.

Abstract: The infestation rate of olives by the olive fruit fly Dacus oleae was investigated in western Algeria. Five sites in the Tlemcen region were chosen differing by their bioclimatic stage (altitude and distance far from the Mediterranean Sea). The first flies were caught at the end of June in the two sites near the sea but till six weeks later in the inland locations. The infestation rate decreased according to the distance to the sea and the altitude. Similar trends were observed in 1987 and 1988, but with different mean values. Sigoise variety, with big fruit and low oil content, was about twice more attacked than Chemlal variety, with small fruit and high oil level. The cardinal orientation in the olive trees did not influence the infestation rate, but between-tree variation was high. The embryonic and larval survival rates might be higher in coastal sites than in inland sites. One parasite, Opius concolor, was found, only in coastal sites and with a low incidence. The results are discussed and compared to others obtained in North Africa and European mediterranean countries but specific climatic conditions are underlined. Difficulties of chemical and biological control in Algeria are emphasized. Zusammenfassung Uber den Schaden durch die Olivenjruchtfliege, Dacus oleae Gmel. (Dipt., Tephritidae) in der Tlemcen-Region, Algerien Im westlichen Algerien wurde die Befallsrate von Oliven durch Dacus oleae untersucht. Zu diesem Zweck wurden 5 Standorte in der Region Tlemcen ausgewahlt, die sich bioklimatisch (nach Hohe und Meeresentfernung) unterschieden. Die ersten Fliegen wurden Ende Juni an 2 Standorten nahe dem Meer gefangen, bis zu 6 Wochen spater noch im Inland. Die Befallsrate nahm mit der Entfernung und Hohe zum Meer ab. Ahnliche Trends waren 1987 und 1988, jedoch mit unterschiedlichen mittleren Werten, zu beobachten. Oliven der Sigoise-Varietat mit grosen Fruchten und niedrigem Olgehalt wurden doppelt so stark befallen wie die Chemlal-Varietat mit kleinen Fruchten und hoherem Olgehalt. Die Lage der Olivenbaume zur Himmelsrichtung beeinfluste die Befallsstarke nicht. Die Befallsunterschiede zwischen den Baumen waren erheblich. Es wurde em Parasitoid, die Sehlupfwespe Opius concolor gefunden, jedoch nur in Meeresnahe und in geringer Dichte. Es werden die Ergebnisse diskutiert und mit jenen, die bisher aus Nordafrika und den europaischen Mittelmeergebieten bekannt sind, verglichen. Die bei der chemischen und biologischen Bekampfung des Schadlings in Algerien auftretenden Probleme werden erortert.

Abstract: One of the major pests in Greek cherry orchards is the cherry fly Rhagoletis cerasi (Diptera: Tephritidae). In order to complete our comparative work on the chorion assembly of other representatives of the fruit flies (e.g. Ceratitis capitata and Dacus oleae) we studied eggshell morphogenesis in the cherry fly. The oocyte is surrounded by several distinct layers which are produced during choriogenesis. The eggshell consists of the vitelline membrane, a fibrous layer of possible water-proofing function, an innermost chorionic layer, endochorionic and exochorionic layers. The endochorion shows a branched configuration with irregular cavities, and the exochorion consists of inner and outer layers for better embryo protection. At the anterior region of the follicle, the hexagonal borders of the follicle cells are created by endochorionic material, covered by both inner and outer exochorion. This area resembles the D. melanogaster chorionic appendages and therefore can serve for plastron respiration. The structural results support the phylogenetic relationships among the tephritids (Rhagoletis is closer to Ceratitis than Dacus). The presence of peroxidase in the endochorion, detected by diaminobenzidine, is consistent with the eggshell hardening at the end of choriogenesis, following the same pattern with the other fruit flies studied so far. Two major chorionic proteins are found both in R. cerasi and in C. capitata and therefore general conclusions can be drawn from this study, concerning the pattern of choriogenesis, which all dipteran insects follow, in order to create a resistant and functional eggshell, and the high conservation of the proteinaceous components of the chorion among species in the order.

Abstract: The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), was reared at three larval densities in ripe mock orange, Murraya paniculata (L.), obtained from five locations in the field. Larvae and preadult survival decreased with increase in larval density. C. capitata field infestation rates varied between locations from 0.5 to 148.4 larvae/kg of fruit. More Dacus dorsalis Hendel were reared from field collected fruits than C. capitata . The weight of mock orange fruit varied between locations from 0.31 to 4.0 g/fruit. Survival and reproduction parameters are discussed in relation to availability of fruit in the field. We conclude that the availability of ripe mock orange fruit in the field ultimately influences the number of fruit flies that survive to the next generation.

Abstract: A field survey on the island of Kauai was done to determine the infestation rates of oriental fruit fly ( Dacus dorsalis Hendel) and melon fly ( D. cucurbitae Coquillett) in papaya ( Carica papaya L. ‘Sunrise’) based on varying levels of visual and “hot spot” colorimetric b indices of fruit ripeness. (The “hot spot” is the most yellow spot on the fruit’s skin surface.) The colorimetric b is a measure of yellowness obtained with the HunterLab LabScan Color Difference Meter. Melon fly never infested ‘Sunrise’ fruits at any stage of ripeness. In contrast, oriental fruit fly infested only one-quarter to fully ripe fruits. Mature green and color-break fruits, or those with values of b ≤ 18.4, were free of oriental fruit fly and melon fly infestations. Data suggest that two-stage hot-water immersion (double dip) treatment is still a viable quarantine treatment for ‘Sunrise’ papaya and that mature green and color-break fruits may be shipped to and marketed in the mainland United States without any treatment.

Abstract: Based on the weekly male catches in pheromone traps and weather data for 2 years (1985, 1986), regression models were developed to predict the densities of melon fruit fly, Dacus cucurbitae Coq., which is an important pest of cucurbit and solanaceous fruits. Among the simple linear regression models, the model SQRT (male counts + 1) = —5.37+0.75 (mean daily temperature in degrees Celsius) was the best, as it explained the highest (68%) variability. The model log(male counts + 1) = —7.54 + 0.35 (maximum temperature) + 0.63 (minimum temperature) —0.02 (maximum × minimum temperature) explained 80% variability, and was considered to be the best for forecasting fruit fly populations.

Abstract: Carrying on our research on the Razzola cultivar to determine the influence of Dacus oleae G. infestation on oil quality (acidity, peroxide value, spectrophotometric indexes, as well as acidic and sterolic composition, polar components and tyrosol contents...) 1991 results are reported. They are then compared with 1990 results, as these two years may be considered typical of quite opposite situations, with regard to both elimatic and to production conditions

Abstract: Actin homologous sequences in the genome of Dacus dorsalis have been isolated and characterized in this study. Coding regions of actin genes are extremely well conserved in eukaryotes, and they have valuable properties for molecular studies. Using a cloned actin gene from Drosophila melanogaster to probe Eco RI digests of D. dorsalis genomic DNA, seven distinct homologous fragments are detectable. Two of these fragments have been subcloned (named pDdAl and pDdA5) and partially characterized by restriction mapping. In addition, regions of cross-homology within the two D. dorsalis subclones, the cloned Drosophila actin gene, and an actin gene from another tephritid species, Ceratitis capitata (Weidemann), have been determined. This has identified what appear to be conserved coding regions and nonconserved flanking and untranslated regions in the cloned fragments.

Abstract: A survey of Bacillus thuringiensis recovered from the environments of olive groves in Greece was carried out. Of 80 soil samples, 24 were found to contain B. thuringiensis with parasporal crystal inclusions; these were tested for toxicity against the olive fruit fly (Dacus oleae). Mortality levels of larvae caused by the different isolates varied from 7 to 87%. Higher levels of mortality were observed if a mixture of relatively pure crystals and spores was used compared with the mortality resulting from either fraction alone. We were able to show that the toxicity of the most active isolate is likely to be specific for D. oleae.

Abstract: Research efforts during the last decade have culminated in the development of an effective trapping method for the control of the olive fruit fly, Dacus oleae (Gmelin). The method combines a food attractant, a phagostimulant, a male sex pheromone, a female aggregation pheromone with additional arrestant and aphrodisiac properties, and a hygroscopic substance on an insecticide-treated wood board. Pilot studies conducted from 1984 to 1988 have shown the efficacy of the method, as well as its limitations. The method eliminated an average of four (three to five) insecticide sprays required per season for the control of this pest, reduced pesticide use by 99% per treatment, and is being introduced gradually by the Greek Ministry of Agriculture to replace the use of bait or cover sprays that have been used for decades.