Quality assessment of the predatory bugs Podisus maculiventris (Say) and Podisus sagitta (Fab.) (Heteroptera: Pentatomidae) after prolonged rearing on a meat—based artificial diet

The predatory stinkbugs Podisus maculiventris and Podisus sagitta were reared for more than 15 consecutive generations on a meat—based artificial diet. When they were returned to a diet of live prey (larvae of the pyralid Galleria mellonella) after different generations on the artificial diet, developmental and reproductive traits were similar to those of bugs continuously reared on live prey. Under laboratory conditions, predation rates for nymphs and adults of both pentatomids on larvae of the noctuid Spodoptera exigua were found to be unaffected by the previous diet. The results suggest that long—term rearing of P. maculiventris and P. sagitta on the meat—based artificial diet did not substantially affect the quality of the predators.     

Influence of Host Pheromone on Egg Parasitism by Scelionid Wasps: Comparison of Phoretic and Nonphoretic Parasitoids

The kairomonal activity of the attractant pheromone for the spined soldier bug, Podisus maculiventris (Hemiptera: Pentatomidae), was investigated by exposing fresh pentatomid egg masses in field traps with or without synthetic pheromone. Predominantly two parasitoids were recovered from exposed eggs of P. maculiventris and Euschistus obscurus: Telenomus podisi Ashmead (a generalist pentatomid egg parasitoid) and Telenomus calvus Johnson (a phoretic specialist on Podisus eggs) (Hymenoptera: Scelionidae). The incidences of T. podisi from P. maculiventris and E. obscurus eggs placed in pheromone-baited and nonbaited traps were not significantly different, suggesting that this oophagous wasp does not use the spined soldier bug attractant pheromone as a kairomone. However, T. calvus was reared almost exclusively from egg masses of P. maculiventris placed inside pheromone-baited traps. These results suggest that T. calvus females orient to volatile chemicals emitted by spined soldier bug males as a searching strategy to find areas likely to contain host eggs, in addition to the previously discovered strategy of using the pheromone to guide their phoretic behavior. The data also indicate that T. calvus can distinguish between the egg masses of these pentatomid hosts at close range.     

Effects of chlorogenic acid-and tomatine-fed caterpillars on the behavior of an insect predator

If generalist insect predators are a selective force contributing to patterns of feeding specialization by insect herbivores, then predators should be deterred from eating allelochemical-fed prey. The attack and feeding behaviors of naive predators (Podisus maculiventris stinkbugs) reared on control caterpillars (Manduca sexta) fed plain diet were compared to experienced predators reared on caterpillars fed tomato allelochemicals. Tomatine-fed prey were found more quickly by both naive and tomatine-experienced predators, and chlorogenic acid-experienced predators were more stimulated to begin searching for prey. However, experienced predators were less likely to attack both chlorogenic acidfed and tomatine-fed caterpillars than were naive predators. These results indicate that allelochemical-fed prey were easier for predators to locate, but allelochemical-containing prey often deterred predation by experienced predtors.     

Effects of diet on development and reproduction of the predatory pentatomids Picromerus bidens and Podisus maculiventris

The effects of five diets (larvae of Galleria mellonella L., larvae of Spodoptera littoralis (Boisduval), eggs of Ephestia kuehniella Zeller, cysts of Artemia franciscana Kellogg and an artificial diet based on bovine meat) on development, survival and reproduction of two predatory stinkbugs, Picromerus bidens L. and Podisus maculiventris (Say), were studied in the laboratory. Both species successfully completed immature development on the foods offered, except for P. bidens on cysts of A. franciscana. Significant effects of diet on developmental duration were found in both species. Total developmental time from second instar to adult ranged from 25.0 to 41.5 days and from 18.7 to 46.0 days in P. bidens and P. maculiventris, respectively. Nymphal survival of P. maculiventris was superior to that of P. bidens on all diets tested. Nymphal survival of P. maculiventris was greater than 92% on all diets except on A. franciscana cysts, yielding only 50% survival to adulthood. Survival of P. bidens fed on eggs of E. kuehniella was higher than that of conspecifics fed on caterpillar prey or artificial diet (89% on flour moth eggs vs. 68 and 80% on G. mellonella and S. littoralis and only 50% on meat diet). Fresh weight of newly emerged females of both pentatomids was affected by the diet offered to the predators during their nymphal stage. Females of P. maculiventris produced viable eggs on all diets except on cysts of A. franciscana and had mean fecundities of 691, 436, 608 and 344 eggs per female on S. littoralis, G. mellonella, E. kuehniella eggs and the meat diet, respectively. Females of P. bidens laid eggs only on live prey with mean fecundities of 94 and 38 eggs per female on S. littoralis and G. mellonella, respectively. The results indicate a lower nutritional plasticity of P. bidens as compared with P. maculiventris. An erratum to this article can be found at     

Influence of feeding interval on reproduction and longevity ofPodisus sagitta (Het.: Pentatomidae)

The effect of various feeding intervals on reproduction and longevity of the predatory bugPodisus sagitta (Fabricius) (Heteroptera: Pentatomidae) was studied in the laboratory. Isolated pairs of adult bugs were given moisture in excess and were fed 1 seventh-instar larva of the greater wax moth,Galleria mellonella (L.), with a mean weight of 90 mg every 1, 3, 7, 14 and 21 days. Reproduction ofP. sagitta reflected well the feeding intervals. Females fed at increasing time intervals reduced reproductive outputs by decreasing oviposition frequency and size of egg batches. Predators fed every 21 days produced a mean of only 1.0 egg per day in comparison with 9.9 eggs per day for females fed daily. Longevity of females fed daily was 110.7 days; females fed less frequently tended to live longer, with a maximum mean longevity of 217.5 days for females fed every 14 days. No cannibalism among adults was observed, but females were occasionally seen to feed on their own eggs. Availability of moisture was found to be essential for the predators to survive during periods of low food supplies. These findings are discussed in relation to the predator's adaptation strategies in conditions of prey scarcity.      

Influence of plant antibiosis through four trophic levels

Summary The effects of an insect herbivore-resistant soybean genotype on relationships between four levels of a trophic system were examined in the laboratory using both greenhouse and field-grown plants. Pre-imaginal development of the predatory pentatomid, Podisus maculiventris (Say), was affected by soybean antibiosis in a manner similar to that of its lepidopteran prey, Pseudoplusia includens (Walker). Pre-imaginal development time was increased, and cumulative weight gain tended to be reduced on both greenhouse and field-grown resistant foliage; although mortality was increased on greenhouse-grown resistant foliage, it appeared unchanged on field-grown foliage. Reproductive capacity of P. maculiventris reared on P. includens larvae that were fed resistant soybean generally was unaffected, although peak progeny production was delayed and extended slightly. Pre-imaginal development and adult emergence of the egg parasitoid Telenomus podisi Ashmead from eggs of P. maculiventris reared on P. includens larvae that were fed resistant soybean were unaffected. However, the overall reproductive capabilities of this parasitoid were reduced. Our results demonstrate that plant antibiosis can influence the biology of organisms over four trophic levels, thus documenting a relationship heretofore undescribed. Determination of the final outcome of the interaction between plant resistance and biological control is difficult. The four trophic level model reported in this study further illustrates the complexity which hinhers a general understanding of these interactions.     

Transport and kinetics of diflubenzuron and pyriproxyfen in the beet armywormSpodoptera exigua and its predatorPodisus maculiventris

Transport and retention of the insect growth regulators (IGRs) diflubenzuron and pyriproxyfen in larvae of the beet armywormSpodoptera exigua (Hübner) and in nymphs of the predatory bugPodisus maculiventris (Say) were investigated. In a first experiment, the retention of orally administered [¹⁴C]radiolabeled isotopes of both compounds in fifth-instar larvae of the beet armyworm was studied. Rate of excretion of both IGRs inS. exigua caterpillars was high, with a 50% excretion time of approximately 6 h after intake. In a second experiment, the transport of the compounds from prey to predator and their retention inside the predator were studied. Fifthinstar nymphs ofP. maculiventris were allowed to feed on caterpillars that had been given contaminated food. For both diflubenzuron and pyriproxyfen, more than 80% of the amount of radiolabel applied was recovered in consumed prey. Low levels of radioactivity (c. 3% of the applied amount of radiolabel) were also found in the fluid regurgitated by the prey larvae when attacked by the predatory bugs. Relatively small amounts of radiolabel (c. 8 and 15% of the amount orally applied to the prey for diflubenzuron and pyriproxyfen, respectively) were ingested byP. maculiventris nymphs when feeding on beet armyworm caterpillars. The data suggest that the predators did not use gut content as food. The pattern of excretion in nymphs ofP. maculiventris differed between compounds. For diflubenzuron, there was a drastic decrease of radioactivity inside the predator body of around 40% within the first 6 h and then the level of retained radiolabel remained stable at 3–4% up to 72 h. For pyriproxyfen, a slow decrease of radioactivity inside the body was observed and at 72 h only 2% of the applied quantity was detected. Results of this study are discussed in relation to the findings from previous studies on the toxicity of both IGRs toP. maculiventris.     

Interaction between Podisus maculiventris and Harmonia axyridis two predators used in augmentative biological control in greenhouse crops

Intraguild predation (IGP) betweenthe pentatomid Podisus maculiventris(Say) and the coccinellid Harmoniaaxyridis (Pallas) in the absence or presenceof the extraguild prey Spodopteralittoralis (Boisduval) and Myzuspersicae (Sulzer) was studied in thelaboratory. Interactions were asymmetric infavor of the pentatomid. Podisusmaculiventris readily fed upon eggs and larvaeof H. axyridis, but adult beetles wererarely attacked. Success of attacks by P.maculiventris was stage dependent, fourthinstars and adults being more successful inkilling ladybeetle larvae than second instars.Attacks by H. axyridis on the pentatomidwere rare and none of them were successful. Theeffect of introducing extraguild prey on thelevel of IGP was tested both in petri dishesand on caged sweet pepper plants. Whensufficient numbers of S. littoralislarvae were present to satiate the pentatomid,predation on H. axyridis larvae decreasedsignificantly, indicating that the coccinellidis a less preferred or less vulnerable prey.When the aphid M. persicae was presentedas extraguild prey, levels of IGP were notaltered. Nymphs of P. maculiventrissuccessfully completed development whenexclusively fed on larvae of H. axyridis,but developmental time was longer than onlepidopteran prey. No pentatomid nymphs reachedadulthood on aphids alone. IGP by P.maculiventris on H. axyridis may be ofsome importance in greenhouse crops, where bothpredators are being used increasingly inaugmentative biological control programs.Nonetheless, it is expected that in practicelarger larvae and adults of H. axyridiswill escape most attacks by the pentatomid.     

Predation by Podisus maculiventris (Hemiptera: Pentatomidae) on Plutella xylostella (Lepidoptera: Plutellidae) larvae parasitized by Cotesia plutellae (Hymenoptera: Braconidae) and its impact on cabbage

Biological control offers potentially effective suppression of the diamondback moth (DBM), Plutella xylostella, a serious pest of Brassica crops. Little is known of whether multiple natural enemies have additive, antagonistic, or synergistic effects on DBM populations. No-choice and choice tests were conducted to assess predation by Podisus maculiventris on DBM larvae parasitized by Cotesia plutellae and unparasitized larvae. In no-choice tests, P. maculiventris preyed on greater numbers of parasitized than unparasitized larvae and greater numbers of young larvae than old larvae. In choice tests with early third instar DBM, there was no difference in predation between parasitized or unparasitized larvae. However, in choice tests with older prey, P. maculiventris preyed on more parasitized than unparasitized larvae. Two field studies were conducted to test if this predator and parasitoid have additive, antagonistic or synergistic effects on DBM populations and plant damage in cabbage (Brassica oleracea var. capitata). In 2002, DBM populations were significantly lower in the presence of C. plutellae but not in the presence of P. maculiventris. There was not a significant interaction between the natural enemies. Plant damage was reduced only with C. plutellae. In 2003, DBM populations were significantly lower in the presence of C. plutellae and P. maculiventris, although the combination of natural enemies did not lead to a non-additive interaction. Plant damage was unaffected by the presence of either natural enemy. Because of its greater predation on parasitized larvae, P. maculiventris could be an intraguild predator of C. plutellae. Yet, their overall combined effect in the field was additive rather than antagonistic.     

Effects of prey availability, facultative plant feeding, and plant defenses on a generalist insect predator

This study examined the effects of feeding interval, access to host plants (thus, a source of sap), and plant defenses on the predatory insect, Podisus maculiventris Say (Hemiptera: Pentatomidae). The experiment consisted of a 2 × 2 design with two feeding intervals (1 day or 5 days) and predators living on either tomato plants or plastic plants. Females fed every day had greater body weights and egg hatch rates than females fed every five days. Females on tomato plants lived longer than females on plastic plants. However, access to plants did not alleviate the effects of low prey level on predator weight or reproductive output. In a second experiment, third instar nymphs were placed on either tomato plants or plastic plants for four days to examine the effects of tomato trichome defenses on these predators. Nymphs on tomato plants experienced 50% mortality compared to 15% mortality for nymphs on plastic plants. Some nymphs living on tomato plants were trapped by the hairy trichomes of the plant; others had gummed up legs from the exudates of the plants’ glandular trichomes, which inhibited their movement and ability to feed on prey. Although predators appeared to benefit from feeding on tomato plants, their ability to live on the plants was negatively affected by the defensive features of the plants. The potential effects of trichome defenses on predator survival and population dynamics must be considered when evaluating the benefits of plants on insect predator life histories and efficacy as biological control agents.     

Toxicity of diflubenzuron and pyriproxyfen to the predatory bugPodisus maculiventris

The susceptibility of the predatory pentatomidPodisus maculiventris (Say) to the insect growth regulators (IGRs) diflubenzuron and pyriproxyfen was investigated in the laboratory. Fifth-instar nymphs were exposed to formulated materials of each compound via direct contact, residual contact and ingestion. Diflubenzuron was harmless toP. maculiventris by direct and residual contact, but was highly toxic when ingested via drinking water. Pyriproxyfen caused severe deformities at ecdysis whatever the method of exposure. Exposure of fifth instars to sublethal concentrations (around LC₁₀) of both compounds had no adverse effects on reproduction of emerging adults. The data suggest that the use of these IGRs in the integrated management of insect pests should be evaluated with caution.     

Rearing ofChaetorellia australis (Dipt., Tephritidae) on an artificial diet

Larvae of the tephritid flyChaetorellia australis Hering, which infests flowerheads of the yellow starthistleCentaurea solstitialis L. (Asteraceae), and which is a candidate species for biological control, of that weed, were reared for the first time and for two consecutive generations on an artificial diet. At a density of 0.5 eggs per g diet a yield of 18.5% F₁ adults (over hatched eggs), was obtained. When the density of eggs per g diet increased, the yield decreased. At 25°C the duration of development from egg to adult was 20–25 days for both generations. F₁ adults reared on artificial diet had an average longevity of 32.0 days for males and 34.9 days for females. The fecundity was 53.3 eggs per female and the egg hatchability 88.8%. These and other biological parameters are similar to those of wild flies.      

Predation rates,survivorship and development ofPodisus maculiventris (Het.: Pentatomidae) on larvae ofLeptinotarsa decemlineata (Col.: Chrysomelidae) andPieris brassicae (Lep.: Pieridae), under field conditions

The mean predation rate per day and the effect of the prey on the development and survival of the various nymphal stages ofPodisus maculiventris (Say) were studied under field-cage conditions. Third instar larvae of the Colorado potato beetleLeptinotarsa decemlineata (Say) and the large white butterflyPieris brassicae (Linnaeus) were used as the prey. The results show that under climatic conditions similar to those occurring in the Thessaloniki region (N. Greece), the 5^th instar nymphs and the adults of the predatorP. maculiventris would be promising agents for the biological control of larvae ofL. decemlineata andP. brassicae.

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Résumé Des recherches de terrain ont été menées afin d'étudier le degré de prédation journalier et l'effet de la proie sur le développement et la survie des différents stades nymphaux deProdisus maculiventris Say en présence de larves du 3^e stade deLeptinotarsa decemlineata (Say) et dePieris brassicae (Linnaeus). Les résultats obtenus montrent que les nymphes du 5^e stade et les adultes du prédateur ont une importante activité prédatrice avec un taux de survie élevé quand ils se nourrissent aux dépens de larves du doryphore ou de la Piéride du chou. Par conséquent, il est très probable quePodisus pourrait être utilisé contre ces ravageurs dans des zones où les conditions climatiques sont proches de celles de la région de Thessaloniki (Grèce du Nord).

     

Influence of diet and photoperiod on development and reproduction of European populations of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae)

The current study examines the effect of photoperiod (16:08 or 12:12 h L:D) and diet (eggs of Ephestia kuehniella Zeller (Lepidoptera: Phycitidae) or the pea aphid Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae)) on the development and reproduction of the multicoloured Asian lady beetle Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). A long-term laboratory population of H. axyridis (since 1998) and a melanic and non-melanic population originating from field collected individuals of H. axyridis in Belgium were used in this study. Long day conditions (16 h photoperiod) shortened development of the field populations with 2–3 days when compared with short day conditions (12 h photoperiod). Oviposition in the field populations was delayed by 1–3 months when reared at a 12 h photoperiod. Dissections indicated that the females were in reproductive diapause. As compared with live pea aphids, a diet consisting of E. kuehniella eggs yielded heavier adult body weights (up to 12%) and increased the number of egg laying days (by 45–169%) for both field populations at a 16 h photoperiod and lengthened adult life span (by 45–92%) under both light regimens. The morph types differed in their response to the foods offered in terms of developmental rate, pre-oviposition period and number of oviposition days. The laboratory and field strains responded differentially to regimens of food and photoperiod. The study indicated a greater nutritional plasticity of the non-melanic morphs which may offer them a competitive advantage that may in part explain the predominance of non-melanic morphs in newly colonized areas.     

Population differences in host use by a seed-beetle: local adaptation, phenotypic plasticity and maternal effects

For insects that develop inside discrete hosts, both host size and host quality constrain offspring growth, influencing the evolution of body size and life history traits. Using a two-generation common garden experiment, we quantified the contribution of maternal and rearing hosts to differences in growth and life history traits between populations of the seed-feeding beetle Stator limbatus that use a large-seeded host, Acacia greggii, and a small-seeded host, Pseudosamanea guachapele. Populations differed genetically for all traits when beetles were raised in a common garden. Contrary to expectations from the local adaptation hypothesis, beetles from all populations were larger, developed faster and had higher survivorship when reared on seeds of A. greggii (the larger host), irrespective of their native host. We observed two host plant-mediated maternal effects: offspring matured sooner, regardless of their rearing host, when their mothers were reared on P. guachapele (this was not caused by an effect of rearing host on egg size), and females laid larger eggs on P. guachapele. This is the first study to document plasticity by S. limbatus in response to P. guachapele, suggesting that plasticity is an ancestral trait in S. limbatus that likely plays an important role in diet expansion. Although differences between populations in growth and life history traits are likely adaptations to their host plants, host-associated maternal effects, partly mediated by maternal egg size plasticity, influence growth and life history traits and likely play an important role in the evolution of the breadth of S. limbatus’ diet. More generally, phenotypic plasticity mediates the fitness consequences of using novel hosts, likely facilitating colonization of new hosts, but also buffering herbivores from selection post-colonization. Plasticity in response to novel versus normal hosts varied among our study populations such that disentangling the historical role of plasticity in mediating diet evolution requires the consideration of evolutionary history.     

Comparative Development and Performance of Artificially Reared versus Host-RearedDiapetimorpha introita(Cresson) (Hymenoptera: Ichneumonidae) Wasps

Diapetimorpha introita(Cresson) (Hymenoptera: Ichneumonidae), a native ectoparasitoid ofSpodopteraspp. pupae, was reared in the laboratory on an artificial diet devoid of any insect host components. Diet-reared wasps demonstrated a propensity to search for and parasitize natural hosts in a field cage trial. Longevity of the diet-reared wasps was comparable with the longevity of wasps reared on host pupae. Survival rate ofD. introitawas 61.3% when reared on diet and 76.3% when reared on host pupae. Wasps reared on the artificial diet had longer developmental times, reduced fecundity, and reduced adult weights compared to wasps reared on host pupae. These studies suggest that future research efforts should focus on increasing fecundity and weight of diet-reared wasps and decreasing the mortality and developmental time of wasps reared on the artificial diet. The ability to rearD. introitaon an inexpensive, artificial diet significantly enhances the potential of mass rearing this parasitoid for inundative releases againstSpodopteraspp.     

Effects of rutin-fed caterpillars on an invertebrate predator depend on temperature

Summary A factorial experiment examined the effects of varying concentrations of the allelochemical rutin in caterpillars and the length of time the caterpillars had fed on the behavioral interactions of predatory stinkbugs (Podisus maculiventris) and their prey (Manduca sexta). Diet had no significant effect on defensive behavior of the caterpillars. The length of time that the caterpillars had fed (1 vs. 24 h) only influenced the frequency of caterpillars knocking the attacking stinkbugs away, with caterpillars knocking the stinkbugs away more often after 24 h of feeding. A second experiment tested the effects of diet (prey fed various concentrations of rutin), temperature (18° C and 28° C) and gender on consumption and growth parameters of fifth instar stinkbugs. At the cooler temperature, the bugs ate more, gained more weight but took twice as long to complete the stadium and consequently had reduced relative consumption and relative growth rates. Diet had no significant effect on biomass gained or stadium duration, but rutin-fed caterpillars did depress the stinkbugs' relative consumption rates. The effect of food quality on relative growth rate (RGR) was temperature dependent; rutin had no significant effect at the cooler temperature, but a high dose of rutin reduced RGR at the warmer temperature. Rutin had a greater negative impact on the females than the males. The effect of rutin on these predators was different than the effect on their prey (this study compared to Stamp (1990, 1992)): the negative effects of rutin seem to impact on the stinkbug's growth rather than on molting.     

Searching behavior and time budgets of the predator Podisus maculiventris

Searching behavior of the predaceous insect Podisus maculiventris (Say) (Heteroptera: Pentatomidae) was investigated in the laboratory to verify assumptions made in a predator search model. Female predators were placed into an arena containing 30 lima bean plants (Phaseolus lunatus L.), each having five numbered leaflets. Prey were third-instar larvae of Mexican bean beetle (Epilachna varivestis Mulsant) at two densities. Predators were observed for 4 h periods as they searched the plant canopy. Results showed that predators searched a greater area and for longer at low prey density than at high prey density. Predators apparently searched plants without using cues, did not search areas of the canopy repeatedly after attacks, and spent approximately 1 h handling prey. Predators spent more time resting than searching, and attack rates were negatively correlated with rest time, but were not correlated with search time. Long resting periods by predators may be a result of energy conservation. The implications for using predators such as P. maculiventris against pests in crops are (i) the predators' searching behavior limits the number of prey attacked, and (ii) the predator may be able to persist at low prey densities better than species with different searching behaviors.     

Genetic Diversity of the Giant Tiger Shrimp (Penaeus monodon) in Thailand Revealed by PCR-SSCP of Polymorphic EST-Derived Markers

A total of 90 ESTs from normal and 157 from subtractive ovarian cDNA libraries of the giant tiger shrimp (Penaeus monodon) were sequenced. SSCP analysis of disulfide isomerase (DSl), zinc finger protein (ZFP), PMO920, and PMT1700 was carried out for population genetic studies of P. monodon in Thai waters. The number of codominant alleles per locus for overall samples was 6 for PMO920, 5 for PMT1700, and 12 for ZFP, and there were 19 dominant alleles for DSI. The observed heterozygosity of each geographic sample was 0.3043–0.5128 for PMO920, 0.3462–0.4643 for PMT1700, and 0.5000–0.8108 for ZFP. Linkage disequilibrium analysis indicated that genotypes of these loci segregate randomly (P > 0.05). Low genetic distance was found between pairs of geographic samples (0.0077–0.0178). The neighbor-joining tree constructed from the average genetic distance of overall loci allocated the Andaman samples (Satun, Trang, and Phangnga) into one cluster, and Chumphon and Trat into other clusters. Geographic differentiation between Satun-Trat and Satun-Phangnga was found only at the ZFP locus (P < 0.05), suggesting low degrees of genetic subdivision of Thai P. monodon.     

In Vitro Rearing of the Parasitoid Exorista larvarum (L.) (Diptera: Tachinidae) on Meat Homogenate-Based Diets

The tachinid Exorista larvarum (L.), a polyphagous gregarious larval endoparasitoid of Lepidoptera, was reared from egg to fecund adult on media containing commercial meat homogenates for babies as the main ingredient. Four media, each containing a diverse homogenate supplemented with extract of Galleria mellonella L. pupae, were tested first. Despite the difference in nutrient content, the kind of homogenate did not significantly affect the adult yields (30.2 to 40.7%) or puparial weights. Two other diets free of host materials (I and II) were then tested. Both were based on Gerber veal homogenate combined with different amounts of yeast extract and chicken egg yolk and were supplemented with wheat germ (I) or saccharose (II). Adult yields (28.7 to 32.7%) and puparial weights did not differ significantly between the two diets. Fly longevity and fecundity of the females obtained on diet I were comparable to those of the females emerged from puparia formed in G. mellonella larvae. Male and female puparial weights were, however, higher and development times longer on the diet than in the host.