Emergence Of Adult Flies Research Articles

Hospedeiros do parasitóide Paraganaspis egeria Díaz, Gallardo & Walsh (Hymenoptera: Figitidae: Eucoilinae) coletados em fezes bovinas e de búfalos, no sul do estado de Goiás

Este estudo verificou as espécies hospedeiros do parasitóideParaganaspis egeria Díaz, Gallardo & Walsh (Hymenoptera: Figitidae: Eucoilinae) em fezes bovinas e fezes de búfalos, coletados no Sul do Estado de Goiás, de janeiro de 1998 a junho de 2004. As pupas foram obtidas por meio do método de flutuação, indivualizadas em cápsulas de gelatina até a emergência dos adultos de moscas ou de seus parasitóides A porcentagem de parasitismo em fezes bovinas e fezes de búfalos foi de 0,5% e 0,8%, respectivamente.

RESIDENTIAL COMPOSTING OF INFESTED FRUIT: A POTENTIAL PATHWAY FOR SPREAD OF ANASTREPHA FRUIT FLIES (DIPTERA: TEPHRITIDAE)

Abstract Composting plant waste is a beneficial practice commonly used by American gardeners, but disposal of infested fruit directly into the environment creates a potential pathway for introduction of insect pests. This study estimates the likelihood of adult emergence for exotic fruit flies (Tephritidae) from residential composting in south Florida. Ripe grapefruits, Citrus × paradisi Macfad., were infested with the Caribbean fruit fly, Anastrepha suspensa (Loew). Half of the infested fruit was placed onto outdoor compost piles and half was maintained under controlled laboratory conditions. Adult fly emergence was recorded daily for 30 d from both the compost piles and control bins. Compost temperature, air temperature, relative humidity, and precipitation were monitored, and the study was repeated 4 times under different seasonal conditions. Despite high mortality of flies from the composted fruit relative to control fruit, the overall risk of a potentially mated female emerging from composted fruit w...

Novos hospedeiros para Hemencyrtus herbertii Ashmead (Hymenoptera: Encyrtidae) coletados em Lavras, Minas Gerais

This study verified the host species of the parasitoid Hemencyrtus herbertii Ashmead (Hymenoptera: Encyrtidae), in Lavras, Minas Gerais, Brazil. The pupae were obtained by the flotation method. They were individually placed in gelatin capsules until the emergence of adult flies or their parasitoids. The overall occurence of parasitism was 6.5%. The occurrence of parasitism presented in the hosts Chrysomya megacephala (Diptera: Calliphoridae) and Sarcodexia lambens (Diptera: Sarcophagidae) was 1.3% and 29.4%, respectively.

Quantitative postharvest contamination and transmission of Penicillium expansum (Link) conidia to nectarine and pear fruit by Drosophila melanogaster (Meig.) adults

This research demonstrated the possibility of conidial transmission of Penicillium expansum by the adult flies of Drosophila melanogaster to mature, sound nectarine and pear fruit. This transmission was accomplished by inserting the fungal conidia adhering either to mouthparts of the contaminated flies or to their abdominal tip into mature, sound nectarine and pear fruit, while making punctures in the fruit skin either for feeding or for oviposition. Accordingly, the mean number of typical P. expansum lesions that appeared due to this transmission per one nectarine or pear fruit subjected to contaminated flies was 4.7 and 2.5, respectively. Also, the mean diameter of these typical lesions was 5.3 and 3.2 mm on the same types of fruit, respectively. When the eggs laid by the contaminated females of D. melanogaster were left to develop until adult fly emergence, the mean number of the flies that emerged per fruit at the end of the life cycle was 48.3 and 24.3 on nectarine and pear fruit, respectively. Also, the mean life cycle duration for the emerged flies was 24.3 and 28.7 days on the same types of fruit, respectively. Moreover, viability of the pathogen conidia that either adhered externally to the various body parts of the contaminated flies or were introduced into their bodies was tested by plating the conidia onto oatmeal agar plates amended with chloramphenicol, following the release of the contaminated flies onto plates or the spread of their ground suspension in saline solution onto the same type of plates. The mean number of typical P. expansum colonies that appeared per plate was 5.3 for external contamination of the flies and 2.4 for internal contamination. The conidia of P. expansum adhering to the various body parts of contaminated flies were first localized on these parts and then photographed under the light microscope after they have been correctly identified. Overall results indicate the possibility of P. expansum conidial transmission by D. melanogaster adults into sound, mature nectarine and pear fruit through their feeding and oviposition punctures.

Laboratory Evaluation of Entomopathogenic Fungi Against Larvae and Adults of Onion Maggot (Diptera: Anthomyiidae)

Laboratory experiments were done to measure the susceptibility of larvae and adults of the onion maggot, Delia antiqua (Meigen) (Diptera: Muscidae: Anthomyiidae) to 27 isolates of entomopathogenic fungi from four genera [Beauveria Vuillemin, Lecanicillium (Petch) Zare&W. Gams, Metarhizium Sorokin, and Paecilomyces Bainier]. A novel bioassay was developed for D. antiqua larvae by using a diet based on mixed vegetable powder. When evaluated in a virulence screen, the fungal isolates caused less mortality of D. antiqua larvae than adults. Only three isolates caused >50% mortality of larvae, whereas 12 isolates caused >50% mortality of adults. Fungal species was a statistically significant factor affecting the mortality of larvae but not of adults. The fungal isolates causing the most mortality of larvae tended to belong to Metarhizium anisopliae (Metschnikoff) Sorokin. Two M. anisopliae isolates (389.93 and 392.93) were evaluated in dose–response bioassays. The median lethal concentrations of the isolates against larvae were 6.1 × 107 conidia ml−1 for isolate 389.93 and 7.6 × 107 conidia ml−1 for isolate 392.93. The emergence of adult flies from pupae was reduced at high concentrations of conidia (3.0 × 108 and 1.0 × 108 conidia ml−1). The median lethal concentrations of the isolates against adults were 1.7 × 107 and 4.0 × 107 conidia ml−1, respectively. Some of the fungal isolates examined may have potential as biological control agents of larvae of D. antiqua and related species.

Laboratory Evaluation of Entomopathogenic Fungi Against Larvae and Adults of Onion Maggot (Diptera: Anthomyiidae)

Laboratory experiments were done to measure the susceptibility of larvae and adults of the onion maggot, Delia antiqua (Meigen) (Diptera: Muscidae: Anthomyiidae) to 27 isolates of entomopathogenic fungi from four genera [Beauveria Vuillemin, Lecanicillium (Petch) Zare & W. Gams, Metarhizium Sorokin, and Paecilomyces Bainier]. A novel bioassay was developed for D. antiqua larvae by using a diet based on mixed vegetable powder. When evaluated in a virulence screen, the fungal isolates caused less mortality of D. antiqua larvae than adults. Only three isolates caused > 50% mortality of larvae, whereas 12 isolates caused > 50% mortality of adults. Fungal species was a statistically significant factor affecting the mortality of larvae but not of adults. The fungal isolates causing the most mortality of larvae tended to belong to Metarhizium anisopliae (Metschnikoff) Sorokin. Two M. anisopliae isolates (389.93 and 392.93) were evaluated in dose-response bioassays. The median lethal concentrations of the isolates against larvae were 6.1 x 10(7) conidia ml(-1) for isolate 389.93 and 7.6 x 10(7) conidia ml(-1) for isolate 392.93. The emergence of adult flies from pupae was reduced at high concentrations of conidia (3.0 x 10(8) and 1.0 x 10(8) conidia ml(-1)). The median lethal concentrations of the isolates against adults were 1.7 x 10(7) and 4.0 x 10(7) conidia ml(-1), respectively. Some of the fungal isolates examined may have potential as biological control agents of larvae of D. antiqua and related species.

Evaluation of Entomopathogenic Fungus Metarhizium anisopliae Against Soil-Dwelling Stages of Cabbage Maggot (Diptera: Anthomyiidae) in Glasshouse and Field Experiments and Effect of Fungicides on Fungal Activity

The effect of two isolates of the entomopathogenic fungus Metarhizium anisopliae (Metchnikoff) Sorokin (389.93 and 392.93) on root-feeding stages of cabbage root fly, Delia radicum (L.), was studied under glasshouse and field conditions. In glasshouse studies, the effect of drenching a suspension of conidia (concentration 1 x 10(8) m(-1), 40 ml per plant, applied on four occasions) onto the base of cabbage plants infested with D. radicum eggs was compared with mixing conidial suspension into compost modules (concentration 1 x 10(8) ml(-1), 25 ml per plant) used to raise seedlings. Drench application reduced the mean number of larvae and pupae recovered per plant by up to 90%, but the compost module treatment had no statistically significant effect. Both application methods reduced the emergence of adult flies from pupae by up to 92%. Most conidia applied as a drench application remained in the top 10-cm layer of compost. Applications of the fungicides iprodione and tebuconazole, which are used routinely on brassica crops, were compatible with using M. anisopliae 389.93 against D. radicum under glasshouse conditions, even though these fungicides were inhibitory to fungal growth on SDA medium. In a field experiment, drench applications of M. anisopliae 389.93 to the base of cauliflower plants at concentrations of 1 x 10(6) to 1 x 10(8) conidia ml(-1) did not control D. radicum populations, although up to 30% of larval cadavers recovered supported sporulating mycelium. Drench applications often exhibited considerable lateral movement on the soil surface before penetrating the ground, which may have reduced the amount of inoculum in contact with D. radicum larvae.

Hemencyrtus herbertii Ashmead (Hymenoptera: Encyrtidae) como parasitóides de dípteros muscóides coletados em Itumbiara, Goiás

This study determined the species of hosts of the parasitoid Hemencyrtus herbertii Ashmead (Hymenoptera: Encyrtidae) in human feces, cattle liver and chicken viscera, collected in Itumbiara, Goias. The pupae were obtained by the flotation method. They were individually placed in gelatin capsules until the emergence of adult flies or their parasitoids. The overall prevalence of parasitism was 23.7%.

Developmental changes of poly(ADP-ribose) polymerase expression in <i>Sarcophaga peregrina</i>

To elucidate the physiological role of poly(ADP-ribose) polymerase (PARP), we studied the levels of PARP mRNA and protein during the developmental stages of Sarcophaga peregrina. PARP mRNA expression changed remarkably throughout the developmental stages. The level of PARP mRNA (the molecular ratio of PARP mRNA to the total RNA) was highest in unfertilized eggs and that of PARP protein (the molecular ratio of PARP protein to the total protein of the crude extract) was high in unfertilized and fertilized eggs and in 1st instar larvae. During the embryogenesis period, the levels of PARP mRNA and protein gradually decreased. The levels of PARP mRNA during larval and pupal periods became less than about 5% of that in unfertilized eggs. After the emergence of adult flies, the levels of PARP mRNA and protein increased both in female and male flies. PARP activity normalized with the total amount of protein in the crude extract changed in parallel to the level of PARP protein throughout the developmental stages. The biological significance of the drastic change of mRNA and protein levels of PARP still remains to be clarified. (Contributed by Takashi SUGIMURA, M.J.A.)

Microhimenópteros parasitóides de dípteros muscóides coletados em diferentes substratos em área de mata em Itumbiara, Goiás

This paper reports the occurrence of parasitoids in pupae of flies (Diptera) collected from several different substrata in Itumbiara, Goias, Brazil. The pupae were isolated by flotation. They were individually placed into gelatin capsules and kept until the emergency of adult flies or their parasitoids. From March 2001 through April 2002, a total of 684 parasitoids and 830 pupae of flies were collected from humans feces, chicken viscera, fish, and bovine kidney. Brachymeria podagrica were identified in a high number of samples. The prevalence of parasitism was of 82.4%.

Interspecific parasite exchange in a mixed colony of birds.

Studies of avian host-parasite interactions rarely include consequences of relationships among hosts for either the host or parasite species. In this study, we examine the ectoparasitic burden of adult and nestling European bee-eaters (Merops apiaster) and rock sparrows (Petronia petronia) in a mixed colony. We found that (1) each bird species had its own species of lice; (2) hematophagous mites parasitized both adults and nestlings of both bird species; (3) Carnus hemapterus, a common parasite of nestling bee-eaters, also infested rock sparrow nestlings, a species not previously described as a host for this dipteran; and (4) whereas C. hemapterus did not show high host specificity within the colony, the emergence of adult flies was synchronized with the start of hatching in bee-eater nests. We suggest that coexistence of these 2 bird species results in parasite exchange, bee-eaters obtaining mites from sparrows and sparrows becoming infested by C. hemapterus. Differences in the detrimental effects of parasite transfer for each host species may result in a process of apparent competition mediated by shared parasites. Interspecific parasite exchange is an important aspect of host-parasite relationships in mixed colonies, which requires further attention.

Spalangia drosophilae (Ashmead) (Hymenoptera: Pteromalidae) como inimigo natural de Archisepsis scabra (Loew) (Diptera: Sepsidae) em fezes bovinas

This paper reports, for the first time, the occurrence of the parasite Spalangia drosophilae (Hymenoptera: Pteromalidae) in pupae of Archisepsis scabra (Diptera: Sespsidae) found in cow manure in the municipality of Cachoeira Dourada, GO, Brazil (18o29´S and 49o´W). Manure samples, collected at two-week intervals, were taken to the laboratory, and the pupae were extracted by water flotation. Each pupa was placed in capsules of colorless gelatin until the emergence of adult flies or their parasites. The parasitism prevalence was 5.7%.

Primeira ocorrência de Triplasta coxalis (Ashmead) em pupas de Palaeosepsis sp. e nova ocorrência de Kleidotoma nigra (Hartig) (Hymenoptera: Figitidae: Eucoilinae) no Brasil

Triplasta coxalis (Ashmeda) (Figitidae: Eucoilinae), was found as a parasitoid of Palaeosepsis sp. (Diptera: Sepsidae) in Itumbiara, GO, Brazil (18o25'S and 49o13'W). The samples of bovine dung were taken from pats 24, 36, 72, 96, 120, 144, 168, 192, 216, and 240 hours of exposition, placed in plastic containers and kept in the laboratory conditions. The pupae were extracted by flotation in water. Pupae were individually placed in gelatin capsules until emergence of adult flies or their parasitoids. Four and one specimens of Triplasta coxalis and Kleidotoma nigra, respectively, were collected. This was the first report on occurrence of the parasitoid Kleidotoma nigra and Triplasta coxalis in Goias.

Preliminary observations on the effects of hydrocortisone and sodium methohexital on development of Sarcophaga ( Curranea) tibialis Macquart (Diptera: Sarcophagidae), and implications for estimating post mortem interval

Larvae of Sarcophaga ( Curranea) tibialis ( S. tibialis) were reared at constant temperature on chicken liver treated with a steroid or a barbiturate at concentrations that would be lethal, half-lethal and twice-lethal doses for humans. Trends to greater mortality at higher drug concentrations were not statistically significant. Larvae exposed to either drug took significantly longer to reach pupation compared to those in the control, while larvae exposed to sodium methohexital passed through pupation significantly faster than those in the control. No systematic relationship was found between drug concentration and development time of larvae or pupae. The total developmental period from hatching to eclosion did not differ between treatments, implying that estimates of post mortem intervals- (PMI) based on the emergence of adult flies will not be affected by the involvement of these drugs in a case. On the other hand, anomalous pupation spans may indicate the presence of barbiturates. These findings are compared with patterns found in another fly fed other contaminants.

Emergência de Haematobia irritans em fezes bovinas no município de Seropédica, Rio de Janeiro

O presente trabalho teve como objetivo estudar a emergência de Haematobia irritans em fezes de bovinos mantidas a campo e em laboratório, além de observar a presença de outros dípteros associados às massas fecais. Foram utilizados dois grupos de fezes bovinas, um à campo e outro em laboratório, sendo cada grupo formado por cinco bolos fecais frescos de tamanho mediano (cerca de 30 cm de diâmetro), aparência opaca, cor esverdeada, presença de fina crosta externa e consistência firme. As fezes foram cobertas com gaiolas de emergência de formato piramidal, apresentando na parte superior um orifício onde foi acoplado um frasco removível; a substituição das fezes foi realizada quinzenalmente. Foram coletados um total de 355 espécimens de H. irritans, sendo 151 provenientes das gaiolas mantidas no campo e 204 em laboratório. Estas diferenças deveram-se provavelmente à menores oscilações de temperatura verificadas no laboratório do que àquelas ocorridas no campo, além da ação de artrópodes predadores, competidores e parasitóides que, provavelmente, interferiram na emergência de H. irritans nas fezes bovinas mantidas no campo. Foi observado maior número de fêmeas em comparação com machos em ambas as condições investigadas. Além de H. irritans, obteve-se outros dípteros associados às fezes bovinas, pertencentes as seguintes famílias: Aulacigastridae, Muscidae, Psychodidae, Sarcophagidae, Sepsidae, Tachinidae e Ulidiidae. Sepsidae foi a mais abundante, com 5.224 exemplares do total de 8.928 dípteros obtidos, seguida por Sarcophagidae com 2.235 espécimens coletados, Muscidae com 1.357, Aulacigastridae com 54, Psychodidae com 46, Ulidiidae com 6 e Tachinidae com 5 exemplares.

Resistance of Immature Mango Fruits to Caribbean Fruit Fly (Diptera: Tephritidae)

Both mature and immature mangoes, Mangifera indica L., grown in subtropical Florida are marketed. Food use of immature mangoes includes being cooked for sauce, powdered for a flavoring agent, pickled, and processed into chutney. Immature mangoes are distinguished from mature mangoes in that they do not ripen after harvest (Reid 1992). Immature mangoes have a whitish flesh, lack juiciness, and have a sour flavor, while mature mangoes have yellow flesh, are juicy, and have a sweet flavor. Mango has been listed as a host of Caribbean fruit fly,Anastrepha suspensa (Loew) (Norrbom & Kim 1988). California, where the largest immature mango market is, maintains a Caribbean fruit fly quarantine on both mature and immature imported mangoes. Mangoes can only be shipped from Florida to California if they have undergone an acceptable postharvest treatment that disinfests them of fruit flies. To our knowledge, there have been no studies to determine to what extent immature mangoes may represent a lower risk for fruit fly infestation than mature mangoes. Peina & Moyhuddin (1997) reviewed mature mango fruit resistance toAnastrepha obliqua (Macquart) and infestability differences among cultivars were suggested to be caused by differences in toxic chemicals, nutrients, or resin ducts. Hennessey & Schnell (1995) determined that for mature fruit, some genotypes are more resistant to Caribbean fruit fly than others. They also suggested highly resistant germplasm accessions could be employed in breeding efforts and integrated pest management systems for control of Caribbean fruit flies. The present investigations were conducted to determine if some germplasm accessions in the immature state were more resistant to Caribbean fruit fly than others. Fruits used in the experiments were from the USDA National Clonal Germplasm Repository at the Subtropical Horticulture Research Station in Miami, FL, where over 150 Mangifera accessions are maintained. The accessions comprise a valuable source of genetic diversity utilized by breeders and researchers from all over the world. Fruits from 18 M. indica accessions (individual trees) were selected based on availability and inclusion in a previous study of mature mangoes (Table 1). Immature mangoes were available from March 21 to June 23, 1996. Tree cultivation practices included fertilization, pruning, and chemical weed control. No insecticides were applied during testing and for at least four months prior to testing. The methods for rearing flies, determining mango maturity, and bioassaying of fruits were previously described in detail (Hennessey & Schnell 1995). Flies were reared on an agar-based diet (Hennessey 1994) which was used as the control in the present study. Stage of maturity of the mangoes was determined for each accession and harvest date by holding 5-10 fruits in the laboratory and observing flesh color, juiciness, and flavor after 5-8 days. Each accession was bioassayed on three dates: early (March-April), middle (May), and late (June) immature period (Table 1). Slices, including peel, from five fruits per accession were bioassayed for each date. Ten mature Caribbean fruit fly eggs were inoculated on each fruit slice and corresponding agar control portions. The corrected mean percentage adult emergence was the criterion used to evaluate resistance. This value was obtained by dividing the percentage of eggs reaching adulthood from each slice by the mean percentage reaching adulthood from five agar controls of the same date. The experiment was completely randomized. Corrected mean percentage adult emergence data from the three harvest dates combined (n = 15) were analyzed with PROC ANOVA and compared among cultivars with the LSD test (SAS Institute 1992). The corrected mean percentage of emergence of adult flies from mangoes varied from 0.0% for 'Saigon Seedling' M13269 to 35.7% for'Keitt' (Table 1). The most resistant group included 15 cultivars that supported less than 28.9% emergence. Hennessey & Schnell (1995) observed that the corrected mean percentage emergence varied from 26.6% for mature 'Tobago Small Red' to 119.0%/c (a higher emergence rate than the control) for mature 'Sabre'. In that study, the group that contained the most resistant cultivar (P = 0.10) consisted of 'Peach', 'Irwin', 'Tommy Atkins', 'Rumani', 'Turpentine', 'Keitt', '13-l', 'Sandersha', 'Zilate', and 'Tobago Small Red' (Table 1). Mature mangoes served as a better substrate for development than did immature mangoes of the same cultivar. Over all cultivars, immature mangoes supported from 2-59% of the emergence compared with mature fruits of the same cultivars did. This could be interpreted to mean that, within cultivars, most immature man-

Effect of Diachasmimorpha tryoni on two non-target flowerhead-feedingtephritids

Laboratory tests were conducted to evaluate the possible effect of a deliberately introduced fruit fly parasitoid, Diachasmimorpha tryoni, on 2 non-target flowerhead-feeding tephritid flies,Trupanea dubautiae and Ensina sonchi. The former is an nativecomposite endemic Hawaiian tephritid which feeds on flowerheads of the native composite shrub, Dubautia raillar dioides; the latter is an inadvertently introduced tephritid infesting flowerheads of the exotic weed, Sonchus oleraceus. Gravid females of D. tryoniwere confined in test cages with field-collected D.raillardioides and S. oleraceus flowerheads infested with late instars of T. dubautiae and E. sonchi,respectively. D. tryoni showed low levels of visiting and probing responses to D. raillardioides flowerheads and relatively higher responses to S. oleraceus flower heads in both the presence and absence of the parasitoid's normal host, the Mediterranean fruit fly, Ceratitis capitata. With 72-h exposure to D. tryoni, 13.9 and 2.6% of T. dubautiaewere attacked by test parasitoids in the absence and presence of C.capitata in the test cage, respectively; while 56.8 and34.2% of E. sonchi were attacked. In contrast, 94.0 and84.0% of C. capitata larvae presented in screened disheswith diet in test cages were attacked by D. tryoni in testswith T. dubautiae and E. sonchi, respectively. Attackof D. tryoni on flowerhead-feeding T. dubautiae andE. sonchi resulted in significant reduction in the emergence ofadult flies, especially in the absence of the parasitoid's normal host.While 8.8–12.8 adult D. tryoni per test (both males andfemales) successfully emerged from medflies, no adult D. tryoniprogeny emerged from T. dubautiae, and only 3 deformed males ofD. tryoni (much smaller than the normal wasp) emerged fromE. sonchi. The relevance of these findings to the safety offuture biological control programs against tephritid pests is discussed.

Primeiro relato do parasitóide Neralsia splendens (Borgmeier) (Hymenoptera: Figitidae) na região do Triângulo Mineiro e Sul de Goiás

Neralsia splendens (Borgmeier), was found as a parasitoid Sarcophagula occidua (Fabricius) (Diptera: Sarcophagidae) in Triângulo Mineiro ( West Minas Gerais) and South Goias, Brazil. Ten samples of bovine dung were taken at random, each month, from pats approximately one week old, placed in plastic containers and taken to the laboratory. Arthropods were extracted by flotation in water. Pupae were individually placed in gelatin capsules until emergence of adult flies or their parasitoids. Eighty four and seventeen specimens of Neralsia splendens were collected at Uberlândia and Itumbiara, respectively.

Constância, dominância e freqüência mensal de dípteros muscóides e seus parasitóides (Hymenoptera e Coleoptera), associados a fezes frescas de bovinos, em Uberlândia, MG

Mensalmente, 10 amostras de esterco bovino com aproximadamente uma semana de idade foram colhidas aleatoriamente nas pastagens, transportadas para o laboratório, e postas em baldes com água. Os artrópodes eram extraídos dessas amostras cinco dias após a coleta no campo. As pupas eram retiradas com peneira e acondicionadas individualmente em cápsulas de gelatina até sua emergência ou a de seus parasitóides. Neste sitio, 50% dos hospedeiros predominaram na estação quente e úmida; os parasitóides predominaram na estação fria e seca. As espécies Palaeosepsis insularis Williston e Eucoilidae sp.3 foram dominantes.

Effect of Two Opiine Parasitoids (Hymenoptera: Braconidae) Introduced for Fruit Fly Control on a Native Hawaiian Tephritid,Trupanea dubautiae(Diptera: Tephritidae)

Abstract Diachasmimorpha longicaudata(Ashmead) andPsyttalia fletcheri(Silvestri) are opiine parasitoids introduced into Hawaii for control of the Oriental fruit fly,Bactrocera dorsalis(Hendel) and the melon fly,Bactrocera cucurbitae(Coquillett), respectively. Both species have recently been mass-reared and released for research in augmentative biocontrol programs. Laboratory and field sleeve cage experiments were conducted to investigate the potential impact of mass-producedD. longicaudataandP. fletcherion a native Hawaiian tephritid,Trupanea dubautiae(Bryan), infesting the flowerheads of the native composite shrubDubautia raillardioidesHillebrand. Gravid females ofD. longicaudataandP. fletcheriwere confined with bloomingD. raillardioidesflowerheads infested with late instarT. dubautiae.BothD. longicaudataandP. fletcherilacked positive oviposition responses toT. dubautiaelarvae in infested flowerheads and caused neither parasitism nor mortality to the flies. However, when larvae were removed from the flowerheads and presented in screened dishes containing artificial diet of the parasitoids' normal rearing hosts (B. dorsalisandB. cucurbitae), bothD. longicaudataandP. fletcherireadily oviposited in the test larvae. Oviposition byD. longicaudatadid not significantly affect the percentage pupation ofT. dubautiae,but did reduce the emergence of adult flies. Oviposition byP. fletcherisignificantly reduced both pupation and adult fly emergence. All progeny of both parasitoid species died as eggs or first-instar larvae. Results from our experiments demonstrate that biological control programs targeted against frugivorous tephritid pests byD. longicaudataandP. fletcherihave no harmful impact on flowerhead-infestingT. dubautiae.