Volatile and Contact Chemicals Released by Nezara viridula (Heteroptera:Pentatomidae) Have a Kairomonal Effect on the Egg Parasitoid Trissolcus basalis (Hymenoptera: Scelionidae)

The responses of females of the egg parasitoid Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae) to volatile and contact chemicals from its host Nezara viridula (L.) (Heteroptera: Pentatomidae) were investigated in a Y-tube olfactometer and under open arena conditions. In the Y-tube tests, volatiles from virgin males and from females in a preovipositional state attracted T. basalis females, while volatiles from host virgin females did not. In an open arena, traces left by N. viridula adults in different physiological conditions function as contact cues inducing the wasps to remain longer in the arena and to change the pattern of their walking behavior. However, only contact kairomones from N. viridula mated females in a preovipositional condition induced an arrestment response characterized by an increase in patch searching time and turning rates and a reduction in linear speed. The chemical ecological implications of these results on this host–parasitoid association are discussed.     

Cabbage waxes affect Trissolcus brochymenae response to short‐range synomones

We show that induced synomones, emitted as a consequence of Murgantia histrionica activity on Brassica oleracea, are adsorbed by the epicuticular waxes of leaves and perceived by the egg parasitoid Trissolcus brochymenae. Leaves were exposed to M. histrionica females placed on the abaxial leaf surface. After 24 h, the leaves were treated mechanically using gum arabic, or chemically using chloroform, on the adaxial surface, and finally the adaxial surface was assayed with T. brochymenae by two‐choice tests in a closed arena. Wasp females responded to mechanically dewaxed cabbage leaf portions with feeding punctures and footprints (Ff) and with feeding punctures, oviposition and footprints (FOf), showing no effect of wax removal. In contrast, the removal of the epicuticular waxes from leaf portions close to FOf, and from leaves with oviposition and footprints (Of), determined the lack of responses by T. brochymenae. Solvent extracts of different treatments were bioassayed, but only FOf triggered parasitoid response. Thus the detection of oviposition‐induced synomones by the parasitoid depends on their adsorption by the epicuticular waxes. Mechanical wax removal from leaf portions contaminated with host footprints (f) also determined a lack of wasp responses, suggesting that the footprints might trigger the induction of a “footprint‐induced synomone” adsorbed onto the epicuticular waxes and exploited by the parasitoid. Leaf portions with the abaxial lamina previously dewaxed and then contaminated by footprints (D+f) of M. histrionica did not affect the parasitoid response, indicating that the abaxial epicuticular waxes are not directly involved in the chemicals induced by M. histrionica footprints.     

The role of contact chemoreception in the host location process of an egg parasitoid

Taste allows insects to detect palatable or toxic foods, identify a mate, and select appropriate oviposition sites. The gustatory system strongly contributes to the survival and reproductive success of many species, yet it is rarely studied in insect parasitoids. In order to locate and assess a host in which they will lay their eggs, female wasps actively search for chemical cues using their sensory organs present mainly on the antennae. In this paper, we studied the role of antennal taste sensilla chaetica in the perception of contact semiochemicals in Trissolcus brochymenae (Hymenoptera: Platygastridae), an egg parasitoid of the brassicaceae pest Murgantia histrionica (Heteroptera: Pentatomidae). Methanolic extracts obtained from male and female hosts elicited action potentials in taste neurons housed in antennal sensilla chaetica, indicating that these sensilla are involved in the perception of non volatile host kairomones. In behavioural assays, wasp females displayed an intense searching behaviour in open arenas treated with host extracts, thus confirming that these kairomones are soluble in polar solvents. We further investigated the extracts by Gas Chromatography-Mass Spectrometry (GC-MS) and found that they contain several compounds which are good candidates for these contact kairomones. This study contributes to better understanding contact chemoreception in egg parasitoids and identifying gustatory receptor neurons involved in the host location process.     

Evaluation of cold-stored eggs of Dolycoris baccarum (Hemiptera: Pentatomidae) for parasitization by Trissolcus nigripedius (Hymenoptera: Scelionidae)

Trissolcus nigripedius Nakagawa (Hymenoptera: Scelionidae) is an egg parasitoid of Dolycoris baccarum L. (Hemiptera: Pentatomidae), a polyphagous insect pest of many crops including soybean. As a method for mass-rearing to augment the parasitoid, cold storage of host eggs were evaluated in the laboratory. After 0 (control), 8, 20, 60, 90, and 120 days of refrigeration, host eggs were given to adult female T. nigripedius. Host acceptance behaviors of the parasitoid, categorized as drumming, oviposition, and marking, on the refrigerated eggs and biological attributes of offspring were assessed. Most of the attributes examined were affected by the refrigeration of host eggs. But host eggs could be refrigerated for up to two months without significant change in emergence rate and sex ratio and with 90% of parasitism. In addition, the second generation of the parasitoid was not negatively affected at all. However, frozen eggs of D. baccarum can not be used for rearing the parasitoid since parasitism rate decreased to 44% on host eggs frozen for 8 days. Refrigeration of D. baccarum eggs could be useful for mass-rearing and augmentation of T. nigripedius to control D. baccarum without reduction in the quality of parasitoid’s progeny. Furthermore, refrigerated eggs could be supplemented in the field to boost the population of T. nigripedius since immature D. baccarum can not hatch after 20 days of refrigeration.     

Antennal gustatory perception and behavioural responses in Trissolcus brochymenae females

Trissolcus brochymenae (Hymenoptera: Platygastridae) is an egg parasitoid that could be used to control stink bugs like Murgantia histrionica (Heteroptera: Pentatomidae), a pest of brassicaceous crops. Before laying their eggs, parasitoid females spend considerable time examining the substrate with their antennae, which are also used during feeding and mating behaviours. This suggests that contact chemoreception plays a prominent role in many aspects of parasitoid ecology. Therefore, we examined the sensitivity of antennal taste sensilla chaetica to several classical tastants including those that are appetitive or aversive. In addition we studied the taste preferences of wasps when presented with these chemicals alone or mixed. The sensilla chaetica of T. brochymenae responded to serial concentrations of sucrose, salts, and quinine, but no concentration-dependent effect was observed when testing sinigrin, a secondary metabolite found in many brassicaceae. However, both sinigrin and quinine inhibited responses to 0.1 M sucrose when mixed with this sugar. Behavioural taste preference assays confirmed that wasps showed a dose dependent preference for sucrose over agarose. In addition, a behavioural avoidance of sucrose solutions containing quinine was observed. This effect was not observed when sinigrin was used as a feeding deterrent. In the two-choice tests the wasp did not discriminate between sucrose solutions mixed with salts and sucrose alone. Further no preference for salts or sinigrin compared to agarose alone was observed. This work represents the first step towards the identification of gustatory receptor neurons implicated in the detection of different types of chemical cues in egg parasitoids.     

Releases of Trichogramma platneri (Hymenoptera: Trichogrammatidae) in Apple Orchards under a Sterile Codling Moth Release Program

Based on the premise that augmented host numbers may help multiply and support parasitoid populations, the egg parasitoid Trichogramma platneri Nargarkatti was released in apple orchards which were participating in a sterile codling moth, Cydia pomonella (L.), release program. Nonviable eggs resulting from matings involving at least one sterile codling moth partner can be successfully parasitized by T. platneri. Grain moth-reared, as well as codling moth-reared, T. platneri were released either in the spring or in the spring and summer oviposition period(s) of wild codling moth. Sentinel codling moth eggs were hung weekly, for 3-day periods, from May until September to determine fluctuations in T. platneri populations both during and between releases. Low numbers of wild or nonviable codling moth eggs or other susceptible host eggs resulted in sufficient eggs to maintain low spring- or summer-introduced T. platneri populations. T. platneri reduced codling moth damage in trees in which the Trichogramma were released.     

In vitro rearing ofTrissolcus basalis [Hym., Scelionidae] an egg parasitoid ofNezara viridula [Hem., Pentatomidae]

In vitro rearing of the egg parasitoidTrissolcus basalis (WOLL.) from eggs collected on the natural hostNezara viridula (L.) was initiated. Several oligidic diets containing insect material (Manduca sexta hemolymph or host egg content) were tested. Our initial medium with 50% hemolymph induced a high egg mortality, but by decreasing the hemolymph concentration, increasing the hen egg yolk concentration and adding 15% of free amino acids mixture, a hatching rate of 85% of the parasitoid eggs was obtained with 39% reaching the second instar and 33% the third instar. In a medium without hemolymph, but with 18% liquid from parasitized host eggs we obtained 90% to 100% hatching, 25 to 27% reaching the second instar and 8% the third instar. We did not obtain pupation from eggsin vitro, but did get pupae and adults from larvae rearedin vivo to second instar and transfered to anin vitro system.      

Genetic variation in the behavioural mechanisms involved in the response of the egg parasitoid Trissolcus brochymenae to contact chemical cues left by the pest Murgantia histrionica

1. The ability of parasitoid females to perceive chemical traces left by their hosts is of utmost importance in the host location process. The behaviours involved in such ability have thus most likely been promoted by natural selection in the course of the evolutionary time. For this to happen, however, there must be significant genetic variation in natural populations on which natural selection could act.
2. Using the isofemale line method and motion analysis, we detected significant intra‐population genetic variation for several walking behaviour traits of the egg parasitoid Trissolcus brochymenae (Hymenoptera: Scelionidae) females responding to chemical traces left by its host Murgantia histrionica (Heteroptera: Pentatomidae).
3. Besides opening new avenues of research on the reproductive strategies, behaviour, and biological control potential of parasitoid wasps, these results also have implications for understanding their life‐history evolution in general.

     

Host location and selection cues in a generalist tachinid parasitoid

Tachinid flies are diverse and ecologically important insect parasitoids. However, the means by which tachinid species locate and select hosts are poorly known. Many tachinids exhibit unusually wide host ranges and they also possess well-developed visual systems. These characteristics suggest that tachinids differ from parasitic wasps in their reliance on various sensory modes and types of cues. A series of behavioral assays using the generalist tachinid Exorista mella Walker (Diptera: Tachinidae) were conducted to examine what types of cues this parasitoid uses to locate and accept hosts, and how the cues used may reflect its ecological relationships with hosts. Female E. mella responded strongly to host motion in assays using both live hosts and host corpses, and this cue is shown to be an important elicitor of attack behavior. Females also responded to volatile chemicals associated with damaged food plants of their host in an olfactometer. Flies responded only weakly to direct visual contact with stationary hosts and odors directly associated with hosts. The behavior of female E. mella changed with experience such that more experienced flies recognized and attacked hosts more readily than did inexperienced flies. The use of general olfactory and visual cues by E. mella may be an effective strategy by this polyphagous parasitoid to locate a broad range of potential hosts.     

Distribution, host specificity, and overwintering of Celatoria bosqi Blanchard (Diptera: Tachinidae), a South American parasitoid of Diabrotica spp. (Coleoptera: Chrysomelidae: Galerucinae)

The genus Diabrotica (Coleoptera: Chrysomelidae) includes a great number of pest species, including some of the most important crops pests of the Americas. However, only five parasitoid species have been recorded for it. The parasitoid Celatoria bosqi Blanchard was the first parasitoid described from Diabrotica spp. in South America, where substantial parasitism has been observed. C. bosqi has been collected almost throughout the South American distribution of its main host, Diabrotica speciosa (Germar), in an area that includes temperate and tropical lowlands, and semiarid to humid highlands. Three Diabrotica species were found to host the parasitoid, D. speciosa (Germar), Hystiopsis sp., and Diabrotica viridula (F.), with a total parasitism of 2.60, 5.55, and <0.02%, respectively. Laboratory experiments with field beetles and puparia, reared in the laboratory, indicate that C. bosqi overwinters obligatorily in overwintering adult host beetles, remaining quiescent in its live host below developmental temperatures. Based on the known climatic range of C. bosqi, and its requirement of adult overwintering hosts, a potential distribution in North America is projected.     

Fecundity and Longevity of Green Vegetable Bug,Nezara viridula, Following Parasitism byTrichopoda giacomellii

The effects of parasitism by the ArgentinianTrichopoda giacomellii(Blanchard) on reproduction and longevity of its host,Nezara viridula(L.) are reported. Parasitoid larvae suppress egg maturation, reducing by 70% the fecundity of mature female hosts during the period of larval development. Egg viability was not affected, but mating frequency was reduced by approximately 50%. When parasitized as newly eclosed adults, 84% of females fail to reproduce. In male hosts, fertility and mating frequency were not affected during the period of larval parasitoid development. In male and reproductively immature female hosts, death was coincident with, or occurred shortly after parasitoid emergence (2–4 days); in mature females, death occurred on average 2 weeks after larval parasitoid emergence. Host mortality occurred as a consequence of tissue damage incurred as the parasitoid larvae emerged from the host. Some individuals survived parasitism though no further reproductive activity (mating or oviposition) occurred. The effectiveness ofT. giacomelliias a biological control agent is discussed in relation to its impact on reproduction and survival of its host and contrasted with the action of otherTrichopodaspecies.     

Assessment ofTrichogramma species for biological control of forest lepidopteran defoliators

In a laboratory study, we determined the potential of threeTrichogramma (Hymenoptera: Trichogrammatidae) species,T. brassicae Bezdenko,T. minutum Riley andT. nr.sibiricum Sorokina, for biological control against six species of forest lepidopteran pests, black army cutworm, hemlock looper, eastern spruce budworm, western spruce budworm, white-marked tussock moth, and gypsy moth. Females of each parasitoid species were offered eggs from each of the six host species. Parasitization and the effect of the host species on the emerging progeny were examined and recorded.Trichogramma minutum had the broadest host range and successfully parasitized four host species out of the six offered.Trichogramma nr.sibiricum had the narrowest host range and parasitized only two species of hosts. Of the six host species, black army cutworm was the most preferred by all threeTrichogramma species; white-marked tussock moth and gypsy moth were not parasitized by any parasitoids. There was a positive correlation between the size of female offspring and their corresponding egg complement in all three parasitoid species. The developmental time of parasitoids from egg to adult was influenced by both the parasitoid and host species. Our results suggest thatT. minutum has the greatest potential for biological control against various forest lepidopteran pests and that the black army cutworm may be the best target candidate for further study.     

Generalism Versus Specialism: Responses of Diadegma mollipla (Holmgren) and Diadegma semiclausum (Hellen), to the Host Shift of the Diamondback Moth (Plutella xylostella L.) to Peas

A population of the diamondback moth Plutella xylostella (L.) (Lepidoptera: Plutellidae) (DBM) was recently found to infest sugar snap- and snowpeas in the Rift Valley in Kenya, causing heavy damage. The influence of this host shift on host location preferences of two parasitoids was investigated: The indigenous Diadegma mollipla (Holmgren) regarded as a relative generalist, and Diadegma semiclausum(Hellen), regarded as highly specific to DBM. The attractiveness of different odour sources was compared for the two parasitoid species using a Y-tube olfactometer using naïve females. D. mollipla was not significantly attracted to any cabbage related odours but showed a significant preference for the DBM infested pea plant when tested against clean air. D. semiclausum was highly attracted to the undamaged cabbage plant and odours related to cabbage. On the other hand, peas infested with DBM, showed no attractiveness to this parasitoid. The results showed that specialisation of D. semiclausum is mediated by host plant signals, associated with crucifers, which are not encountered in DBM feeding on peas. For D. mollipla,although a frequent parasitoid on DBM in crucifers, volatiles emitted by these plants might not be used as primary cues for host location. This species may respond largely to chemicals yet unknown and associated with a variety of plant-herbivore interactions.     

An evaluation of some natural enemies of >Nezara viridula in northern California

Natural enemies associated with eggs of >Nezara viridula (L.) (Heteroptera: Pentatomidae) wereevaluated by placing sentinel egg masses inweeds and cultivated tomato and bean crops innorthern California. Egg predation wasgenerally less than 10% and normally involvedpredators with chewing mouth parts. Predatorsseldom destroyed an entire egg mass, typicallyeating <40 eggs per exploited mass.Laboratory evaluation of >25 species ofpotential arthropod predators revealed that fewfed on >N. viridula eggs to any extent;however, numerous species fed on >N.viridula nymphs. Five species of eggparasites were recovered from sentinel eggmasses: >Trissolcus basalis (Wollaston),>Gryon obesum Masner and >Telenomuspodisi Ashmead (Scelionidae); and>Ooencyrtus californicus Girault and >O.johnsoni (Howard) (Encyrtidae). The major eggparasite was >T. basalis, the only exoticmember of the parasite guild; it typicallyparasitized 100% of the eggs in an exploitedegg mass. The results indicate thatparasitization of eggs and predation of smallnymphs can be important biotic mortalityfactors for >N. viridula populations innorthern California. It is suggested that acombination of factors – viz., eggparasitization, nymphal predation, regionalshortage of overwintering sites, and localshortages of suitable hosts – maintains thisexotic pest at relatively low levels in theregion.     

The ovipositing female of Ooencyrtus telenomicida relies on physiological mechanisms to mediate intrinsic competition with Trissolcus basalis

Ongoing studies by our group showed that the outcome of the intrinsic competition between two solitary egg parasitoids, Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae) and Ooencyrtus telenomicida (Vassiliev) (Hymenoptera: Encyrtidae), is dominated by O. telenomicida. In this article we investigated the role played by the ovipositing O. telenomicida female in the suppression of a T. basalis competitor. Laboratory experiments were conducted by allowing an O. telenomicida female to puncture the eggs of Nezara viridula (L.) (Heteroptera: Pentatomidae) with her ovipositor (= no oviposition) or to parasitize them. The results show that O. telenomicida relies on some physiological mechanisms to mediate its interspecific intrinsic competition with T. basalis. In fact, the emergence of T. basalis was strongly reduced in host eggs that were parasitized either before or after being punctured by O. telenomicida at fixed time intervals (5, 15, 30, or 45 h). The low percentage of emergence of T. basalis (ranging from approximately 4–20%) was a consequence of the delay and growth rate reduction of larval development. Furthermore, the percentage of eclosion of N. viridula nymphs was negatively affected by the O. telenomicida female’s punctures (96% from healthy host eggs, 4% from punctured host eggs). Host eggs punctured or oviposited in by O. telenomicida showed alterations in the ooplasm including some melanized‐like areas near the hole made with the ovipositor; such alterations indicate that the adult parasitoid releases substances that affect the host eggs survival. These results suggest that the O. telenomicida female influences both the physiological interspecific parasitoid‐parasitoid interaction, as well as the host‐parasitoid interaction, providing, for the first time in egg parasitoids, evidence that physiological suppression of some competitive egg parasitoids is mediated by the ovipositing female.     

Vine mealybug sex pheromone increases citrus mealybug parasitism by Anagyrus sp. near pseudococci (Girault)

The present study was aimed at elucidating the role of lavandulyl senecioate (LS), the sex pheromone of Planococcus ficus, in host selection of the parasitoid Anagyrus sp. near pseudococci. Field trials were carried out in Portugal, Italy and Israel. The effect of LS on the parasitism rate of the wasp was determined by exposing sentinel mealybugs combined with pheromone dispensers impregnated with LS, in comparison with other baits: lavandulyl isovalerate (LI); planococcyl acetate (PAc); and unbaited control traps. In addition, in order to study the host location behavior of A. sp. near pseudococci, pheromone dispensers were placed at three different distances: inside the trap, 30 or 60 cm away from the trap. The number of parasitoid females inside the traps, the number of parasitized mealybugs, and the number of days required for the first parasitoid emergence were recorded. The response of A. sp. near pseudococci females to different doses of LS (25–1350 μg) was also evaluated using sticky plate traps. The rate of mealybug parasitism by A. sp. near pseudococci was significantly increased by LS in the three parasitoid populations. PAc and LI had no significant effect on the wasp parasitism rate in most of the trials. However, the Italian population of the parasitoid responded to PAc, showing apparently a different behavioral pattern. The number of parasitoid females trapped did not significantly differ between tested doses of LS. The use of LS as an arrestant in host location by the A. sp. near pseudococci female is discussed.     

The Response Specificity of <Emphasis Type="Italic">Trichogramma</Emphasis> Egg Parasitoids towards Infochemicals during Host Location

Parasitoids are confronted with many different infochemicals of their hosts and food plants during host selection. Here, we investigated the effect of kairomones from the adult host Pieris brassicae and of cues present on Brussels sprout plants infested by P. brassicae eggs on the behavioral response of the egg parasitoid Trichogramma evanescens. Additionally, we tested whether the parasitoid’s acceptance of P. brassicae eggs changes with different host ages. The wasps did not discriminate between olfactory cues from mated and virgin females or between mated females and males of P. brassicae. T. evanescens randomly climbed on the butterflies, showing a phoretic behavior without any preference for a certain sex. The parasitoid was arrested on leaf parts next to 1-day-old host egg masses. This arrestment might be due to cues deposited during oviposition. The wasps parasitized host eggs up to 3 days old equally well. Our results were compared with former studies on responses by T .brassicae showing that T. evanescens makes less use of infochemicals from P. brassicae than T. brassicae.     

Host discrimination and interspecific competition of Trissolcus nigripedius and Telenomus gifuensis (Hymenoptera: Scelionidae), sympatric parasitoids of Dolycoris baccarum (Heteroptera: Pentatomidae)

Trissolcus nigripedius Nakagawa and Telenomus gifuensis Ashmead (Hymenoptera: Scelionidae) are solitary egg parasitoids of Dolycoris baccarum L. (Heteroptera: Pentatomidae), a polyphagous seed-sucking bug of agricultural crops. Field examinations revealed that the two parasitoids are the most common species, but only a single species emerge from a host egg mass. To explain this observation we tested two hypotheses of interspecific host discrimination and asymmetry in competitive interaction between Tr. nigripedius and Te. gifuensis. Trissolcus nigripedius and Te. gifuensis could discriminate host egg pre-parasitized by either self or conspecific like other scelionid parasitoids that use external mark on host eggs. When provided with host eggs pre-parasitized by each other, both Tr. nigripedius and Te. gifuensis multiparasitized 94% and 100% of the host eggs without interspecific host discrimination, respectively. Interestingly, from the multiparasitized eggs irrespective of oviposition sequence, progeny of Te. gifuensis always survive better than Tr. nigripedius. Telenomus gifuensis is superior in immature competition probably due to shorter egg incubation period after oviposition, hence progeny of Te. gifuensis become first instar faster than that of Tr. nigripedius. However, adult Tr. nigripedius is always superior competitor in possessing and guarding the host eggs even after oviposition against Te. gifuensis. Therefore, the asymmetry in competitive interaction between Tr. nigripedius and Te. gifuensis may explain the emergence of a single species from a host egg mass in the field in spite of no interspecific host discrimination.     

Oviposition and reproductive performance of a generalist parasitoid (Trichogramma pretiosum) exposed to host species that differ in their physical characteristics

The response of generalist egg parasitoids to alternative natural hosts that are present simultaneously is not well known. We investigated the behavior of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) in relation to two field hosts Helicoverpa armigera Hübner and Spodoptera litura Fabricius, in choice and no choice tests. We quantified the effects of natal host species and post-emergence adult age on the oviposition preference of the parasitoids. H. armigera eggs were consistently preferred over S. litura eggs, regardless of the natal host and adult age. When only S. litura eggs were available as hosts, they were parasitized at statistically similar rates to H. armigera eggs (average of 17 ± 2.7 vs. 13 ± 3.0, H. armigera to S. litura). The adult lifespan and lifetime fecundity of T. pretiosum were variable but were affected by natal host species and/or host species to which they were exposed. Mean lifespan and fecundity of parasitoids that had developed in H. armigera eggs and were exposed to H. armigera eggs for oviposition were 13.9 ± 1.8 days and 98.7 ± 11.0 adult offspring. By contrast, those that developed in S. litura eggs and were exposed to S. litura eggs for oviposition lived for 7 ± 0.9 days and produced 53.8 ± 8.0 adult offspring. The ovigeny index (OI) was significantly lower in the parasitoids exposed to H. armigera eggs than in those exposed to S. litura eggs, regardless of the natal host, indicating that H. armigera eggs sustain the adult parasitoids better than S. litura eggs. These results are used to predict parasitoid behavior in the field when both hosts are available.     

Host specificity of the egg pupal parasitoid Fopius arisanus (Hymenoptera: Braconidae) in La Reunion

Fopius arisanus is a polyphagous parasitoid of Tephritidae, which has been recently introduced to La Réunion Island as part of a classical biological control programme. We carried out laboratory experiments to assess the host specificity of this parasitoid, initially reared on Bactrocera zonata, and then offered for parasitization the eight local tephritid pest species. Naive or experienced parasitoid females were given tephritid eggs in no choice tests. Fopius arisanus females parasitize all fly species but parasitism varies with host species. No adult wasps emerge from Bactrocera cucurbitae and the survival of this species is only slightly affected by parasitism. Dissections show that the late instars of this fly may eliminate the parasitoid by encapsulation. When developing on Ceratitis capitata, Ceratitis rosa, Dacus ciliatus, Dacus demmerezi, and Neoceratitis cyanescens, parasitoid survival rate ranges from 10 to 25%. Bactrocera zonata and Ceratitis catoirii are the best hosts, yielding parasitoid survival rates of more than 70% with no premature mortality. The egg-larval mortality of C. capitata, C. rosa, D. ciliatus, and N. cyanescens, and the pupal mortality of D. demmerezi, are significantly increased by parasitism. The size of emerging adults is affected by host species and is correlated to pupal weight. Bactrocera zonata would be a favorable host to support routine colonization of F. arisanus for mass production of this parasitoid.