Papayae Drew Research Articles

Species composition of Bactrocera fruit flies (Diptera: Tephritidae) and their parasitoids on horticultural commodities in Batu City and Malang District, East Java, Indonesia

Abstract. Setiawan Y, Hamdoen FM, Muhammad FN, Hata K, Tarno H, Wang J. 2024. Species composition of Bactrocera fruit flies (Diptera: Tephritidae) and their parasitoids on horticultural commodities in Batu City and Malang District, East Java, Indonesia. Biodiversitas 25: 305-311. Bactrocera Macquart, 1835 fruit flies (Diptera: Tephritidae) are among the most important pests in horticultural commodities worldwide, including horticultural crops in Indonesia. Trapping is suggested to control, eradicate, and suppress fruit flies. The presence of natural enemies is a very important factor in the indicators of agroecosystem balance. This study aimed to monitor the species composition of Bactrocera fruit flies and their parasitoids in several horticultural commodities such as apples, large chili, red guava, sweet citrus, and tomatoes in Batu City and Malang District. Trapping and host-rearing methods were used in this research. A total of 7,124 individuals of Bactrocera were collected using a Steiner trap baited with methyl eugenol. They consisted of six species: Bactrocera carambolae Drew & Hancock, 1994; Bactrocera cucurbitae (Coquillett, 1899); Bactrocera dorsalis (Hendel, 1912); Bactrocera verbascifoliae Drew & Hancock, 1994; Bactrocera papayae Drew & Hancock, 1994; and Bactrocera umbrosa (Fabricius, 1805). The B. carambolae, B. dorsalis, and B. papayae were the three predominant species collected using Steiner traps baited with methyl eugenol. Based on the host-rearing method, B. carambolae and B. dorsalis were found in red guava fruit. Only one parasitoid species, Opius sp., was found in red guava fruit. These results provide valuable insights into the distribution of Bactrocera on horticultural commodities in Batu City and Malang District and the potential challenges regarding parasitoid presence.

Biogeography, Speciation and Taxonomy within the genus Bactrocera Macquart with application to the Bactrocera dorsalis (Hendel) complex of fruit flies (Diptera: Tephritidae: Dacinae)

The genus Bactrocera Macquart comprises a large group of some 750 species distributed across the Asia-Pacific and Afrotropical regions. Most of these have been described and revised by Drew (1989), Drew & Hancock (1994) and Drew & Romig (2013, 2022). A taxonomic study of such a large and diverse group of species provides valuable information that can be used in the elucidation of concepts on biogeography and evolution that are presented in this paper. While a wider discussion of this genus and its many complexes of sibling species awaits a future publication, in this paper we discuss the Bactrocera dorsalis (Hendel) complex in light of current knowledge of biogeography and evolution in the Asia-Pacific region. Within the dorsalis complex, 70 species were recognized in South-East Asia by Drew & Romig (2013) and eight listed for Papua New Guinea and Australia by Drew (1989). Seventy-nine species are now included in this paper. Within this complex, two major groups occur, one with species responding to methyl eugenol and the other to cue lure. The 34 non-cue lure responding group of species are discussed, most of which respond to methyl eugenol and seven of which are recognized as having pest status, namely, B. carambolae Drew & Hancock, B. caryeae (Kapoor), B. dorsalis (Hendel), B. kandiensis Drew & Hancock, B. occipitalis (Bezzi), B. ochroma Drew & Romig and B. papayae Drew & Hancock. An eighth species, Bactrocera invadens Drew, Tsuruta & White is included in this discussion on the basis of its molecular similarity to B. dorsalis. The remaining group of 45 species, mostly cue lure-responding and including the pest species B. pyrifoliae Drew & Hancock and B. syzygii White & Tsuruta, are also discussed. Morphological and ecological data are presented for each pest species and their biosecurity risks assessed. In addition, new data based on further research on the male aedeagus have demonstrated that B. carambolae, B. occipitalis, B. papayae and B. invadens are markedly different from B. dorsalis in the dimensions and shape of the glans and preglans appendix. Based on this evidence, and that presented by Drew & Romig (2016), the withdrawal of B. papayae and B. invadens from synonymy with B. dorsalis by Drew & Romig (2016) remains valid, while the similarity in aedeagus characters between B. papayae and B. philippinensis further supports the synonymisation of these two species. The remainder of the 34 non-cue lure responding species are distributed from the Indian subcontinent, across South-East Asia, Papua New Guinea and north-eastern Australia, some with restricted geographic distributions and specific host plant species. Comments on the reliability of molecular phylogenies in the Dacini are included, with the published mitogenome of 'Dacus longicornis' regarded, on morphological evidence, as data based on a misidentification of Dacus (Mellesis) polistiformis (Senior-White), and the recent synonymy of B. albistrigata (de Meijere) with B. frauenfeldi (Schiner) considered to be based on insufficient evidence.

Epicuticular chemistry reinforces the new taxonomic classification of the Bactrocera dorsalis species complex (Diptera: Tephritidae, Dacinae).

Bactrocera invadens Drew, Tsuruta & White, Bactrocera papayae Drew & Hancock, and Bactrocera philippinensis Drew & Hancock, key pest species within the Bactrocera dorsalis species complex, have been recently synonymized under the name Bactrocera dorsalis (Hendel). The closely related Bactrocera carambolae Drew & Hancock remains as a discrete taxonomic entity. Although the synonymizations have been accepted by most researchers, debate about the species limits remains. Because of the economic importance of this group of taxa, any new information available to support or deny the synonymizations is valuable. We investigated the chemical epicuticle composition of males and females of B. dorsalis, B. invadens, B. papayae, B. philippinensis, and B. carambolae by means of one- and two-dimensional gas chromatography–mass spectrometry, followed by multiple factor analyses and principal component analysis. Clear segregation of complex cuticule profiles of both B. carambolae sexes from B. dorsalis (Hendel) was observed. In addition to cuticular hydrocarbons, abundant complex mixtures of sex-specific oxygenated lipids (three fatty acids and 22 fatty acid esters) with so far unknown function were identified in epicuticle extracts from females of all species. The data obtained supports both taxonomic synonymization of B. invadens, B. papayae, and B. philippinensis with B. dorsalis, as well as the exclusion of B. carambolae from B. dorsalis.

Forced hot-air treatment against Bactrocera papayae (Diptera: Tephritidae) in papaya

The Asian papaya fruit fly, Bactrocera papayae Drew and Hancock, was treated with hot-water immersion and forced hot air to develop a phytosanitary heat treatment schedule. Hot-water immersion tests were conducted with 12- and 24-h-old eggs and with first and third instar larvae to compare the relative thermotolerances of this fruit fly among these life stages. The 24-h-old eggs, the most thermotolerant among the four life stages tested, were subjected to time and temperature tests using cage-infested papaya fruits in a forced hot-air chamber. Heating the papayas to a minimum core temperature of 47.7 °C (95% confidence interval 47.2–48.3 °C) was estimated to induce probit-nine mortality based on a probit analysis of the data. Confirmatory tests in which papayas infested with 24-h-old eggs were heated to a minimum fruit core temperature of 47.2 °C that was maintained for 0–30 min followed by hydrocooling to a fruit core temperature of ≈25 °C resulted in the complete mortality of an estimated treated population of 43,425 eggs aged 24 h (99.9931% mortality at the 95% confidence level). Therefore, heating the papaya fruits to a core temperature of 47.2 °C for a minimum dwell time of 30 min, which was the longest dwell time in the confirmatory tests, may serve as a phytosanitary heat treatment schedule for the control of B. papayae in papaya fruits.

Effect of Temperature on the Development and Survival of Immature Stages of the Carambola Fruit Fly,Bactrocera carambolae, and the Asian Papaya Fruit Fly,Bactrocera papayae, Reared On Guava Diet

Members of the Bactrocera dorsalis Hendel (Diptera: Tephritidae) complex constitute well-recognized destructive pests of fruits in peninsular Thailand. The development and survival of immature stages of the carambola fruit fly, Bactrocera carambolae Drew & Hancock, and the Asian papaya fruit fly, Bactrocera papayae Drew & Hancock, were compared at six constant temperatures of 15, 20, 25, 27, 30, and 35°C, 70 ± 5% relative humidity, and a photoperiod of 12:12 (L:D). The objectives were to determine the effect of temperature on the developmental stages for optimizing rearing and to understand the geographical pattern of occurrence of these fruit fly species. A strong and positive linear relationship was observed between temperature and developmental rate of immature stages of B. carambolae. Similarly, a strong and positive linear relationship was observed between temperature and developmental rate of B. papayae. A temperature summation model was used to estimate the lower threshold temperature and the thermal constant. Bactrocera papayae was significantly faster in development and higher in survival and appeared to be better adapted to low temperatures than B. carambolae, as it exhibited the lowest threshold temperatures at all immature stages. The observed differences in response to various temperatures revealed to some extent the impact of temperature on these species’ distribution in peninsular Thailand and other parts of the world.

Evidence of weak genetic structure and recent gene flow between Bactrocera dorsalis s.s. and B. papayae, across Southern Thailand and West Malaysia, supporting a single target pest for SIT applications.

BackgroundBactrocera dorsalis s.s. (Hendel) and B. papayae Drew & Hancock, are invasive pests belonging to the B. dorsalis complex. Their species status, based on morphology, is sometimes arguable. Consequently, the existence of cryptic species and/or population isolation may decrease the effectiveness of the sterile insect technique (SIT) due to an unknown degree of sexual isolation between released sterile flies and wild counterparts. To evaluate the genetic relationship and current demography in wild populations for guiding the application of area-wide integrated pest management using SIT, seven microsatellite-derived markers from B. dorsalis s.s. and another five from B. papayae were used for surveying intra- and inter-specific variation, population structure, and recent migration among sympatric and allopatric populations of the two morphological forms across Southern Thailand and West Malaysia.ResultsBasic genetic variations were not significantly different among forms, populations, and geographical areas (P > 0.05). Nonetheless, two sets of microsatellite markers showed significantly different levels of polymorphisms. Genetic differentiation between intra- and inter-specific differences was significant, but low. Seventeen populations revealed three hypothetical genetic clusters (K = 3) regardless of forms and geographical areas. The genetic structure of sympatric populations slightly changed during the different years of collection. Recent gene flow (m ≥ 0.10) was frequently detected whether samples were sympatric or allopatric. Ninety-five of 379 individuals distributed across the given area were designated as recent migrants or of admixed ancestry. As a consequence of substantial migration, no significant correlation between genetic and geographic distances was detected (R2 = 0.056, P = 0.650).ConclusionsAccording to the 12 microsatellite variations, weak population structure and recent gene flow suggest that there is no status for cryptic species between B. dorsalis s.s. and B. papayae forms in Southern Thailand and West Malaysia. Both forms can be treated as a single target pest for the SIT program in an area-wide sense. Additionally, the result of species identification based on molecular data and morphological character are not congruent. The use of independent, multiple approaches in the characterization of the target population may ensure the effectiveness and feasibility of SIT-based control in the target area.

Effect of temperature on the development and survival of immature stages of the carambola fruit fly, Bactrocera carambolae, and the Asian papaya fruit fly, Bactrocera papayae, reared on guava diet.

Members of the Bactrocera dorsalis Hendel (Diptera: Tephritidae) complex constitute well-recognized destructive pests of fruits in peninsular Thailand. The development and survival of immature stages of the carambola fruit fly, Bactrocera carambolae Drew & Hancock, and the Asian papaya fruit fly, Bactrocera papayae Drew & Hancock , were compared at six constant temperatures of 15, 20, 25, 27, 30, and 35°C, 70 ± 5% relative humidity, and a photoperiod of 12:12 (L:D). The objectives were to determine the effect of temperature on the developmental stages for optimizing rearing and to understand the geographical pattern of occurrence of these fruit fly species. A strong and positive linear relationship was observed between temperature and developmental rate of immature stages of B. carambolae. Similarly, a strong and positive linear relationship was observed between temperature and developmental rate of B. papayae. A temperature summation model was used to estimate the lower threshold temperature and the thermal constant. Bactrocera papayae was significantly faster in development and higher in survival and appeared to be better adapted to low temperatures than B. carambolae, as it exhibited the lowest threshold temperatures at all immature stages. The observed differences in response to various temperatures revealed to some extent the impact of temperature on these species’ distribution in peninsular Thailand and other parts of the world.

An Evaluation of the Species Status ofBactrocera invadensand the Systematics of theBactrocera dorsalis(Diptera: Tephritidae) Complex

AbstractThe genus Bactrocera (Tephritidae) contains >500 species, including many severe pests of fruits and vegetables. Although native to tropical and subtropical areas of Africa, India, Southeast Asia, and Australasia, a number of the pest species, largely members of the Bactrocera dorsalis (Hendel) complex, have become widespread through accidental introduction associated with agricultural trade. The B. dorsalis complex includes several morphologically and ecologically similar pests, making species designations uncertain. One of these, Bactrocera invadens Drew, Tsuruta, and White, endemic to Sri Lanka, has spread across Africa in the last decade and become a major agricultural pest. We sequenced one mitochondrial and two nuclear genes from 73 specimens, belonging to 19 species to construct phylogenies and examine species relationships and limits within the genus Bactrocera and several species of the B. dorsalis complex-specifically addressing the placement of B. invadens. Results indicate the B. dorsalis complex is polyphyletic. B. invadens and several other species within the B. dorsalis complex (B. dorsalis, Bactrocera papayae Drew &Hancock, and Bactrocera philippinensis Drew & Hancock) are also paraphyletic with respect to each other and probably represent a single genetically indistinguishable, phenotypically plastic, pest species that has spread throughout the world.

Comparison of methyl eugenol metabolites, mitochondrial COI, and rDNA sequences of Bactrocera philippinensis (Diptera: Tephritidae) with those of three other major pest species within the dorsalis complex

Males of the oriental fruit fly, Bactrocera dorsalis (Hendel) and some of its sibling species have strong affinity for methyl eugenol (ME). Methyl eugenol ingested by male flies is biotransformed in the crop to two ME metabolites that eventually accumulate in the rectal gland, which is known to serve as a reservoir for B. dorsalis sex pheromones. When fed with ME, males of laboratory and wild B. philippinensis Drew and Hancock selectively accumulated two metabolites, 2-allyl-4,5-dimethoxyphenol and (E)-coniferyl alcohol, in the rectal gland, as was seen for B. dorsalis sensu stricto, B. invadens Drew, Tsuruta and White, and B. papayae Drew and Hancock. Phylogenetic analysis of COI and rDNA sequence data of these four taxa also revealed a close relationship among B. philippinensis, B. dorsalis s.s., B. invadens, and B. papayae (all four are members of the dorsalis species complex). This result corroborates pheromone analysis. The usefulness of pheromonal analysis as a chemotaxonomy tool to complement molecular and other analysis in differentiation of closely related sibling species within the Bactrocera dorsalis complex, for which use of morphological characters had been inadequate, is highlighted.

Mating Compatibility Among Four Pest Members of the <I>Bactrocera dorsalis</I> Fruit Fly Species Complex (Diptera: Tephritidae)

Bactrocera dorsalis (Hendel), Bactrocera papayae Drew & Hancock, Bactrocera philippinensis Drew & Hancock, and Bactrocera carambolae Drew & Hancock are pest members within the B. dorsalis species complex of tropical fruit flies. The species status of these taxa is unclear and this confounds quarantine, pest management, and general research. Mating studies carried out under uniform experimental conditions are required as part of resolving their species limits. These four taxa were collected from the wild and established as laboratory cultures for which we subsequently determined levels of prezygotic compatibility, assessed by field cage mating trials for all pair-wise combinations. We demonstrate random mating among all pair-wise combinations involving B. dorsalis, B. papayae, and B. philippinensis. B. carambolae was relatively incompatible with each of these species as evidenced by nonrandom mating for all crosses. Reasons for incompatibility involving B. carambolae remain unclear; however, we observed differences in the location of couples in the field cage for some comparisons. Alongside other factors such as pheromone composition or other courtship signals, this may lead to reduced interspecific mating compatibility with B. carambolae. These data add to evidence that B. dorsalis, B. papayae, and B. philippinensis represent the same biological species, while B. carambolae remains sufficiently different to maintain its current taxonomic identity. This poses significant implications for this group's systematics, impacting on pest management, and international trade.

Piecing together an integrative taxonomic puzzle: microsatellite, wing shape and aedeagus length analyses of Bactrocera dorsalis s.l. (Diptera: Tephritidae) find no evidence of multiple lineages in a proposed contact zone along the Thai/Malay Peninsula

Bactrocera dorsalis (Hendel) and B. papayae Drew & Hancock represent a closely related sibling species pair for which the biological species limits are unclear; i.e. it is uncertain if they are truely two biological species, or one biological species which has been incorrectly split taxonomically. The geographical ranges of the two taxa are thought to abut or overlap on or around the Isthmus of Kra, a recognised biogeographic barrier located on the narrowest portion of the Thai Peninsula. We collected fresh material of B. dorsalis s.l. (i.e. B. dorsalis s.s.+ B. papayae) in a north–south transect down the Thai Peninsula, from areas regarded as being exclusively B. dorsalis s.s., across the Kra Isthmus, and into regions regarded as exclusively B. papayae. We carried out microsatellite analyses and took measurements of male genitalia and wing shape, both used previously to separate the taxa. No significant population structuring was found in the microsatellite analysis, consistent with one, predominantly panmictic population. Both morphological datasets showed consistent, clinal variation along the transect, without disjunction. No evidence supported historical vicariance driven by the Isthmus of Kra, and no dataset supported the current taxonomy of two species. Rather, within and across the area of range overlap or abutment between the two species, only continuous morphological and genetic variation was recorded. Recognition that morphological traits previously used to separate these taxa are continuous, and that there is no genetic evidence for population segregation in the region of suspected species overlap, is consistent with a growing body of literature that reports no evidence of biological differentiation between these taxa.

Development of Allele-Specific Single-Nucleotide Polymorphism-Based Polymerase Chain Reaction Markers in Cytochrome Oxidase I for the Differentiation of Bactrocera papayae and Bactrocera carambolae (Diptera: Tephritidae)

Differentiation of Bactrocera papayae Drew & Hancock and Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae) based on morphological characters has often been problematical. We describe here a single-nucleotide polymorphism (SNP)-based polymerase chain reaction (PCR) assay to differentiate between these two species. For detection of SNPs, fragments derived from each species were amplified using two primer pairs, COIF/COIR and UEA7/UEA10, sequenced, and aligned to obtain a contiguous 1,517-bp segment. Two new sets of primers were designed based on the 11 SNPs identified in the region. Results of the SNP-PCR test using any one of these species-specific primer sets indicate that these two species could be differentiated on basis of presence or absence of a band in the gel profile. We also tested the SNP-PCR primers on Bactrocera umbrosa F., Bactrocera cucurbitae Coquillett, Bactrocera latifrons Hendel, and Bactrocera tau (Walker) but did not detect any band in the gel, indicating the likelihood of a false positive for B. papayae is nil. This SNP-PCR method is efficient and useful, especially for immature life stages or when only adult body parts of the two species are available for identification, as encountered often in quarantine work.

Distribution and eradication of an exotic tephritid fruit fly in Australia: relevance of invasion theory

AbstractData from the eradication of the incursion of Bactrocera papayae Drew and Hancock (Dipt.: Tephritidae) in Australia (1995–1998) are used to assess the significance of various aspects of invasion theory, including the influence of towns on establishment, influence of propagule pressure on the pattern of establishment, and the existence of source‐sink dynamics. Because there were no sentinel traps in place, considerable spread had occurred before the eradication campaign started. The distribution of fly density around the epicentre in the town of Cairns and a transect along the main traffic routes to the north and south fitted a Cauchy model with a tail having the same slope as a power model with an exponent of −2.4 extending to 160 km. The Cauchy model indicated that 50% of the flies on the transect would have occurred within 3.2 km of the epicentre, 90% within 13.2 km, and 99% within 60 km. The two major satellites at Mareeba (35 km from the epicentre in Cairns) and Mossman (65 km) were not used for the transect data and had respectively 15 and 30 times the density predicted by the model. The proportion of traps that caught flies (a measure of site occupancy) fell with distance from the epicentre. B. papayae was trapped consistently on only three of the 16 rainforest transects that were surveyed and these were relatively close to urban areas where eradication efforts were intense. Despite there being no eradication effort in the rainforest, the trends to extinction were similar to those in adjacent areas. The strategy of initially concentrating eradication efforts on the core and major satellites while maintaining a quarantine barrier at the airport and the boundaries of the infested area appears to be the key to the containment and rapid eradication of the incursion.

Sexual maturity and intraspecific mating success of two sibling species of the Bactrocera dorsalis complex

Abstract Bactrocera carambolae Drew & Hancock and B. papayae Drew & Hancock (Diptera: Tephritidae), two closely related sibling species in the B. dorsalis (Hendel) complex were shown to have different rates of sexual maturity. The response of B. carambolae males to methyl eugenol was observed to begin 10 days after emergence and increased with age. The attractancy peaked at 28 days after emergence and above. The males were also found to require a higher dosage of methyl eugenol (1 mg) for optimal response. These results are in contrast with those of B. papayae reported previously. The response to methyl eugenol was also observed to correspond with the age when first mating was performed.After eclosion, both sexes of B. carambolae mated approximately 2 weeks later and showed significantly lower matings/individual when compared with B. papayae in a 60‐day observation period. Both sexes of B. papayae and males of B. carambolae were able to remate on the next day. However, B. carambolae females required a minimum refractory period of 8 days in order to be sexually receptive again.During the 60‐day period, the mating propensity in B. papayae (100% success) was higher than B. carambolae (71–87% success) (P < 0.05). This observation was substantiated by a higher intraspecific mating success of B. papayae as compared to B. carambolae in a field cage (P < 0.001).

Ecological significance of male attractant in the defence and mating strategies of the fruit fly, Bactrocera papayae

AbstractAfter being acclimatized to feeding on fruit flies, the Asian house gecko, Hemidactylus frenatus Duméril & Bibron (Gekkonidae:Squamata), consumed fewer methyl eugenol (ME) fed male fruit flies, Bactrocera papayae Drew & Hancock (Tephritidae: Diptera) than when offered ME‐deprived males. After one‐day exposure to only ME‐fed males, the geckos avoided feeding on female flies when in the presence of ME‐fed males. When mechanically disturbed, the ME‐fed males spontaneously ejaculated a rectal secretion which contains phenyl propanoids that deter the predator.The ME‐fed males also competed significantly better than normal (ME‐deprived) males for virgin females. Male B. papayae converts ME to three other phenyl propanoids which act in concert as a sex pheromone to attract females during courtship and as an allomone to the gecko.

Potential suitability of North Queensland rainforest sites as habitat for the Asian papaya fruit fly, Bactrocera papayae Drew and Hancock (Diptera: Tephritidae)

This study: (i) established that the introduced papaya fruit fly, Bactrocera papayae Drew and Hancock, was not present in three widely separated rainforest sites; (ii) established, based on our knowledge of host use, the suitability of those sites as habitat for the papaya fruit fly; and (iii) raised the question of potential impacts of papaya fruit fly invasion of rainforests on the local and endemic fauna and flora. Data were collected between February and June 1996 from vegetation surveys, fruit fly trapping and records of insects reared from fruits collected in rainforest plots. The vegetation survey results indicate that habitat suitability for the papaya fruit fly is highly variable between the three sites sampled. No papaya fruit fly individuals were collected over the course of the study, either from traps or reared from collected fruits. Endemic tephritid species were, however, collected using both of these sampling methods. Based on analyses of potential host availability, the papaya fruit fly has the potential to become established in any of the three 1 ha plots surveyed. There is currently a lack of evidence to confirm or refute the presence of populations of the papaya fruit fly in rainforest areas. Highly focused monitoring strategies need to be employed to further assess the status of this species and the potential environmental and ecological impact(s), if any, that have escaped current detection. Ultimately, many native and endemic species of fauna and flora may be endangered by this species should populations become established in the rainforests of North Queensland.

Contribution of Biological Control to Integrated Pest Management of Tephritid Fruit Flies in the Tropics and Subtropics

The biological control of pest tephritid flies using parasitoids has been successful in relatively few subtropical and tropical regions. The best documented successes were in Hawaii and Florida, USA, Fiji and southern Europe. There were relatively limited successes in Australia, Costa Rica and Mexico. With the accidental establishment of new pest tephritids, such as Bactrocera latifrons (Hendel) in Hawaii or Bactrocera papayae Drew and Hancock in Australia, foreign exploration for new parasitoids is essential. A renewal of interest in classical biological control has recently occurred, although not at the same level as in the 1940s and 1950s. New parasitoid species are currently being obtained for several tephritids, such as Ceratitis capitata (Weidemann), B. latifrons and Anastrepha suspensa (Loew). The advances in mass rearing and quality control technology for parasitoids has enabled researchers to perform large-scale field testing of these parasitoids to determine the potential of augmentative releases. Numerous studies on the augmentative release of parasitoids have been done. Historically, the larval—pupal parasitoid Diachasmimorpha longicaudata (Ashmead) has been the most frequently studied parasitoid, due to the ease of rearing this species. However, recent successes in rearing other species with different biologies, e.g. the egg—pupal parasitoid Biosteres arisanus (Sonan), the gregarious eulophid, Tetrastichus giffardianus (Silvestri) and the pupal parasitoid, Coptera sp., will enable researchers to broaden the repertoire of parasitoid species for the future. Both successes and failures in augmentative releases have occurred. Without knowledge of the behavioural ecology of parasitoids, the reasons for success or failure can only be surmised. Recent research on the dispersal and host habitat finding of tephritid parasitoids will provide insights into improving augmentation and conservation strategies. The integrated pest management (IPM) of tephritid flies in the tropics has been less well-developed than research and programmes for tephritids in temperate zones. Significant emphasis is now being placed on the development of quarantine treatment methods that are environmentally sound; thus IPM will take a larger role. Several existing pest management strategies are reviewed which show the potential for compatibility with the activities of tephritid parasitoids. These include trap cropping, insecticides with selective toxicity to the target pests, mass trapping with parapheromones, the sterile insect technique and field sanitation.