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With the potential to process the world's agricultural and food waste, provide sustainable fodder for livestock, aquaculture, and pet animals, as well as act as a source of novel biomolecules, the black soldier fly, Hermetia illucens, has been launched into the leading position within the insects as feed industry. Fulfilment of these goals, however, requires mass‐rearing facilities to have a steady supply of neonate larvae, which in‐turn requires an efficient mating process to yield fertile eggs; yet, little is known about adult reproductive behavior, nor what physiological factors lead to its emergence. Moreover, fertile egg production tends to be highly variable in colony. Therefore, this review brings together what is currently known of the organismal biology of H. illucens, compiling information on adult morphology, physiology, biogeography, genomics, and behavioral ecology. As a holistic synthesis, it highlights several directions of interest for research to follow. [ABSTRACT FROM AUTHOR]

In the mass‐rearing of insects for sterile insect technique (SIT), it is important to maintain the quality of mass‐reared males so that they can compete with wild males in mating with wild females. Mass‐reared insects sometimes have shorter pre‐mating periods and higher mating frequencies than their wild conspecifics. Indeed, this was the case for mass‐reared individuals of the melon fly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae), used in the SIT program to eradicate the melon fly on the Southwest Islands of Japan. Therefore, I hypothesized that divergent artificial selection for age at reproduction altered these traits in the melon fly as well. To examine the effects of eggs produced by younger parents on each generation, six artificially selected lines were established, for which eggs were collected from young (Y lines) and old (O lines) females. Then, the pre‐mating periods and mating frequencies in males and females of the selected lines were compared. The results show a decreased pre‐mating period and an increased mating frequency in younger lines compared to older lines, which was driven by males rather than females. These traits ensure efficient offspring production in mass‐rearing, and are likely advantageous to the success of SIT programs. The impact of artificially selecting for these traits, especially in males, on insect quality and the efficiency of SIT is discussed. [ABSTRACT FROM AUTHOR]

In Sterile Insect Technique (SIT) programs, massive numbers of insects are reared, sterilized, and released in the field to impede reproduction of pest populations. The domestication and rearing processes used to produce insects for SIT programs may have significant evolutionary impacts on life history and reproductive biology. We assessed the effects of domestication on sexual performance of laboratory reared Queensland fruit fly, Bactrocera tryoni, by comparing an old (49 generations) and a young colony (5 generations). We evaluated mating propensity, mating latency, copula duration, sperm transfer, and ability to induce sexual inhibition in mates. Overall, both males and females from the old colony had greater mating propensity than those from the young colony. Copula duration was longer when females were from the old colony. There was no evidence of sexual isolation between the colonies as males and females from the two colonies had similar propensity to mate with flies from either colony. Males from the old colony transferred more sperm regardless of which colony their mate was from. Finally, males from both colonies were similarly able to induce sexual inhibition in their mates and were also similarly able to secure copulations with already‐mated females. Positive effects of domestication on sperm transfer, coupled with maintained ability to induce sexual inhibition in mates and to secure copulations with previously mated females, highlights that domestication may have little effect, or even positive effects, on some aspects of sexual performance that may advantage mass‐reared B. tryoni in SIT programs. [ABSTRACT FROM AUTHOR]

BACKGROUND Like numerous other animals, biocontrol agents (BCAs) of arthropod pests carry various microorganisms that may have diverse effects on the biology of their eukaryote hosts. We postulated that it is possible to improve the efficacy of BCAs by manipulating the composition of their associated microbiota. The parasitoid wasp Anagyrus vladimiri (Hymenoptera: Encyrtidae) from a mass‐rearing facility was chosen for testing this hypothesis. RESULTS: High‐throughput sequencing analysis indicated that fungal abundance in A. vladimiri was low and variable, whereas the bacterial community was dominated by the endosymbiont Wolbachia. Wolbachia was fixed in the mass‐rearing population, whereas in field‐collected A. vladimiri Wolbachia's prevalence was only approximately 20%. Identification of Wolbachia strains from the two populations by Multi Locus Sequence Typing, revealed two closely related but unique strains. A series of bioassays with the mass‐rearing Wolbachia‐fixed (W+) and a derived antibiotic‐treated Wolbachia‐free (W–) lines revealed that: (i) Wolbachia does not induce reproductive manipulations; (ii) W– females have higher fecundity when reared individually, but not when reared with conspecifics; (iii) W+ females outcompete W– when they share hosts for oviposition; (iv) longevity and developmental time were similar in both lines. CONCLUSIONS: The findings suggest that W+A. vladimiri have no clear fitness benefit under mass‐rearing conditions and may be disadvantageous under lab‐controlled conditions. In a broader view, the results suggest that augmentative biological control can benefit from manipulation of the microbiome of natural enemies. [ABSTRACT FROM AUTHOR]

Campoplex capitator is an ichneumonid parasitoid with a narrow host range, comprising grapevine moth pests. Despite being considered one of the possible candidates for biocontrol of Lobesia botrana, knowledge about its biology is limited and mass‐rearing for commercial purposes is still lacking. This research provides a quantitative analysis of the C. capitator courtship and mating behavior. C. capitator mating sequence was analyzed by high‐speed video recordings. Main behavioral parameters, with special reference to male wing fanning and antennal tapping, were quantified and linked with mating success. Furthermore, we analyzed the occurrence of population‐level behavioral asymmetries during C. capitator sexual interactions and their impact on male success. Results showed that male wing fanning was crucial to successfully approach the female. Males achieving higher mating success performed wing‐fanning at higher frequencies over unsuccessful ones. After wing fanning, most of males palpated the female's body with their antennae, before attempting copulation. The overall mating success was >70%, with a rather long copula duration (254.76 ± 14.21 s). Male wing‐fanning was lateralized on the left at population level, while antennal tapping displays were right‐biased. Side‐biased male displays do not differ in terms of frequency and duration of their main features. This research adds basic knowledge to the C. capitator behavioral ecology. Since rearing protocols for C. capitator are being developed, male wing fanning frequency may represent a useful benchmark for monitoring mate quality over time, tackling mating success reductions due to prolonged mass‐rearing. [ABSTRACT FROM AUTHOR]

Queensland fruit fly [Bactrocera tryoni (Froggatt), Diptera, Tephritidae] is the most devastating insect pest impacting Australian horticulture. The Sterile Insect Technique (SIT) is an important component of tephritid pest management programs. However, mass‐rearing and irradiation (to render insects sterile) may reduce the fitness and performance of the insect, including the ability of sterile males to successfully compete for wild females. Manipulation of the gut microbiome, including the supplementation with bacterial probiotics shows promise for enhancing the quality of mass‐reared sterile flies, however there are fewer published studies targeting the larval stage. In this study, we supplemented the larval stage of mass‐reared B. tryoni with bacterial probiotics. We tested several individual bacteria that had been previously isolated and characterized from the gut of wild B. tryoni larvae including Asaia sp., Enterobacter sp., Lactobacillus sp., Leuconostoc sp. We also tested a consortium of all four of these bacterial isolates. The fitness parameters tested included adult survival in field cages, laboratory mate selection of bacteria supplemented males by bacteria nonsupplemented females, and laboratory locomotor activity of adult flies. None of the bacterial probiotic treatments in the current study was significantly different to the control for field survival, mate selection or locomotor activity of adult B. tryoni, which agree with some of the other studies regarding bacterial probiotics fed to the larval stage of tephritids. Future work is needed to determine if feeding the same, and/or other probiotics to adults, as opposed to larvae can positively impact survival, mating performance, mating competitiveness and locomotor activity of B. tryoni. The bacterial group(s) and function of bacterial species that increase fitness and competitiveness is also of interest to tephritid mass‐rearing programs. [ABSTRACT FROM AUTHOR]

The African edible bush‐cricket, Ruspolia differens (Serville) (Orthoptera: Tettigoniidae), is an economically valuable insect in sub‐Saharan Africa. For its mass‐rearing, suitable diets that can sustain its performance need to be identified. This study aimed at finding inflorescence diets of 10 host plant species and their mixtures that result in the highest R. differens production. We reared newly hatched nymphs to adults on inflorescences of single host species, and also on a gradient of five diversifying dietary mixtures consisting of one and mixtures of two, three, five, and seven host plant species. For the single host‐plant diets, the developmental time was shortest on Pennisetum purpureum, Chloris gayana, and Brachiaria ruziziensis (approximately 63 days), whereas the fresh weight was highest on B. ruziziensis and P. purpureum (approximately 0.383 g). Survival was highest (>65%) on C. gayana, P. purpureum, B. ruziziensis, Setaria sphacelata, and Sporobolus pyramidalis, and lowest on Panicum maximum, Hyparrhenia rufa, Cynodon dactylon, and Paspalum scrobiculatum (<40%). With respect to diet mixtures, the developmental time was significantly shorter (on average 16 days shorter), and survival was higher, in the most diversified diets compared to the least diversified diets. The contents of polyunsaturated fatty acids and fatty acid composition did not differ significantly among the diets. However, the content of monounsaturated fatty acids differed significantly among the diets and there was a significant diet*sex interaction. From the applied point of view, based on our results, for maximal weight and survival plus fast development, we recommend rearing on P. purpureum, C. gayana, B. ruziziensis, and S. sphacelata, and on dietary mixtures of inflorescences. These findings are important in designing large‐scale rearing programs for this species. [ABSTRACT FROM AUTHOR]

Insects commonly rely on olfactory, gustatory and visual cues when deciding where to lay eggs. The olfactory cues that stimulate oviposition in the Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), are not well understood. Here, we show that two known oviposition stimulants of the Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)—γ‐octalactone and benzothiazole—strongly elicit aggregation and oviposition in B. tryoni. Two other known oviposition stimulants of B. dorsalis—ethyl tiglate and 1‐octen‐3‐ol—elicit aggregation but not oviposition. Highlighting species overlap, but also differences, in oviposition stimulants, these findings have practical application for mass‐rearing in which vast numbers of flies are reared for sterile insect technique programs and may also have practical application in the development of pest management and monitoring tools. [ABSTRACT FROM AUTHOR]

Tachinid parasitoids deserve to be better exploited as natural enemies of insect pests. The development of efficient mass‐rearing techniques for these entomophagous insects may encourage their use in biological control programs. Exorista larvarum (L.) (Diptera: Tachinidae) is a Palearctic species, which has been introduced in northern America for the control of the gypsy moth, Lymantria dispar (L.). The potential use of this polyphagous parasitoid of Lepidoptera against other forest and agricultural pests encourages research aimed at the improvement of techniques for its rearing, including protocols for storage at low temperature. This technology allows a certain degree of control over the speed of development of the stored insects and assists mass‐rearing facilities that have to match production with demand, especially during field outbreaks of pests. With the aim of developing storage protocols for E. larvarum, we investigated the effects of storage for 1–4 weeks of 1‐day‐old puparia at 15 °C. Lower temperatures (5 and 10 °C) and longer storage periods were excluded following the outcome of preliminary experiments. Parasitoid emergence and quality control parameters of the female flies obtained from the stored puparia were evaluated. In addition, female lipid body reserves were measured. The temperature of 15 °C proved to be suitable for all the durations tested, although some detrimental effects were observed following storage (e.g., lower longevity and fecundity). Our findings may prove useful to increase the flexibility of E. larvarum colony management. With the aim of increasing the flexibility of Exorista larvarum (Diptera: Tachinidae) colony management, experiments were carried out to test low‐temperature storage of puparia. An extended developmental time was found, but also a quality reduction in some cases. Overall, cold storage proved useful for the purposes of this study. [ABSTRACT FROM AUTHOR]

Anastrepha obliqua (Macquart) (Diptera: Tephritidae), commonly known as the West Indies fruit fly, is a pest species of mango, plum (both Anacardiaceae), and other commercial crops in various countries in the Neotropics, including Mexico, Central and South America, and the Caribbean islands. Currently, the sterile insect technique (SIT) is used to control this pest. Here, the sexual competitiveness of mass‐reared sterile A. obliqua males was evaluated against wild males in field cages. In the first experiment, fertile mass‐reared males had similar sexual performance as fertile wild males reared on mango and tropical plum. In the second experiment, sterile mass‐reared males had better sexual performance than sterile wild males recovered from mango and tropical plum. In the third experiment, fertile wild males recovered from mango had better sexual performance than sterile mass‐reared males. The relative sterility index (RSI) was 0.32, indicating low acceptance of sterile males by wild females. The induced sterility index estimated by Fried's test produced a coefficient of 0.4, indicating that irradiation affected the sexual performance of the mass‐reared males, which had reduced sexual performance compared to wild males. We discuss our results in the context of mass‐rearing and sterilization as part of the SIT programs used to control A. obliqua. The sexual competitiveness of mass‐reared sterile Anastrepha obliqua (Diptera: Tephritidae) males was evaluated in field cages against wild males. Irradiation affected the sexual performance of the mass‐reared males, which had reduced sexual performance compared to wild males. Reduction in irradiation dose could improve the performance of sterile males and induce a greater sterility with wild females. [ABSTRACT FROM AUTHOR]

Abstract: Aging in all organisms is inevitable. Male age can have profound effects on mating success and female reproduction, yet relatively little is known on the effects of male age on different components of the ejaculate. Furthermore, in mass‐reared insects used for the Sterile Insect Technique, there are often behavioral differences between mass‐reared and wild males, while differences in the ejaculate have been less studied. The ejaculate in insects is composed mainly of sperm and accessory gland proteins. Here, we studied how male age and strain affected (i) protein quantity of testes and accessory glands, (ii) the biological activity of accessory gland products injected into females, (iii) sperm viability, and (iv) sperm quantity stored by females in wild and mass‐reared Anastrepha ludens (Diptera: Tephritidae). We found lower protein content in testes of old wild males and lower sperm viability in females mated with old wild males. Females stored more sperm when mated to young wild males than with young mass‐reared males. Accessory gland injections of old or young males did not inhibit female remating. Knowledge of how male age affects different ejaculate components will aid our understanding on investment of the ejaculate and possible postcopulatory consequences on female behavior. [ABSTRACT FROM AUTHOR]

Tapachula-7 is a genetic sexing strain of Anastrepha ludens ( Loew) ( Diptera: Tephritidae) developed for the application of the sterile insect technique ( SIT). To improve the sexual performance of this strain, a mass-reared colony was established from males selected for their sexual competitiveness., Males from selected colonies are more sexually competitive than nonselected males. The present study aimed to analyse the demographic changes recorded in the study colony throughout four consecutive generations, comparing this colony with the parental colony and a wild strain., The results obtained showed that, in the selected strain, fecundity increased, whereas survival diminished, compared with the laboratory parental strain. The increases in fecundity rates were observed at the first generation after selection. No changes were observed in the duration of the reproductive period in the selected strain., Compared with wild flies, selected flies had lower life expectancy, earlier and shorter reproductive period, and greater daily fecundity at young ages (10-30 days), although with lower lifetime fecundity rates., The four generations of the selected colony showed similar patterns of survival and reproduction. The better mating performance and the increase in early fecundity suggest that selection could contribute to improve rearing efficiency and SIT effectiveness. [ABSTRACT FROM AUTHOR]

The sterile insect technique ( SIT) has been applied successfully for the control of several fruit fly species of economic importance. In species with lek mating systems, as in the Mexican fruit fly, Anastrepha ludens ( Loew) ( Diptera: Tephritidae) - where the variance in male mating success is high, males have to compete with other males, and where wild females are highly selective - the success of SIT depends on the sexual competitiveness of mass-reared sterile males. However, mass-rearing conditions result in selection of sexual behavioral traits that differ from wild flies, reducing mating competitiveness of sterile flies and SIT efficiency. Artificial selection in mass-rearing colonies, based on male mating success, represents an alternative to improve the sexual performance of sterile males. Here, we evaluated the effect of selection of A. ludens mass-reared males based on their mating competitiveness. Two modes of selection were compared, one single selection event on parental flies, and continuous selection along four consecutive generations. For the offspring of each treatment in each generation, we evaluated male mating success, its association with post-copulatory behavior through female remating inhibition, and life-history traits that are key for mass-rearing, such as immature survival and reproduction. Field cage mating tests revealed that wild males were more competitive than mass-reared males (selected and unselected). Although no significant differences were found between mass-reared selected and non-selected males, in the fourth generation males from the selected colonies performed better than males from the non-selected colonies and their mating competitiveness was similar to that of wild males. No consistent differences were observed in mating latency, copulation duration, or ability to inhibit female remating. Survival and fecundity decreased with increasing rearing generations, except in the colony with continuous selection where fecundity and fertility increased. [ABSTRACT FROM AUTHOR]

The sterile insect technique (SIT) is currently used to control Mexican fruit fly Anastrepha ludens Loew (Diptera: Tephritidae). However, mass-rearing can alter the quality of released males. If males that are mass-reared have behaviours different from those of their wild counterparts, then this may diminish the effectiveness of SIT. Questions remain as to whether wild females may be able to detect the male condition before, during and/or after copulation with a mass-reared male. In the present study, copula duration, female remating, female fecundity and fertility of both mass-reared and wild A. ludens are evaluated. Marked differences are found between mass-reared and wild females. Specifically, mating latency is longer and copula duration is shorter for wild females compared with mass-reared females. Importantly, there are no significant differences in mating latency, copula duration or remating probability between wild females paired with either mass-reared or wild males. All mass-reared females remate, whereas only approximately half of the wild females remate after first mating with either a wild or mass-reared male. Fecundity of wild females mated to either wild or mass-reared males is approximately one-third lower than that of mass-reared females, confirming that mass-reared females may have been selected for high fecundity and are adapted to laboratory conditions. Fertility of females that mate with a wild male for only 10 min is not significantly different from that achieved via a full-length copulation. By contrast, females mating with mass-reared males need copulation durations of at least 40 min to achieve fertility comparable with that achieved via a full-length copulation. The findings of the present study have important implications for A. ludens controlled through SIT and broaden our understanding on the copulatory and post-copulatory behaviours between wild females and mass-reared males. [ABSTRACT FROM AUTHOR]

The sterile insect technique ( SIT) involves the inundative release of irradiated (sterile or partially sterile) insects to decrease population levels in a target pest species. The effectiveness of SIT programs depends on sterile males mating successfully and inducing reproductive failure in wild females, or in the F1 generation in the case of lepidopteran species. Thus, from the perspective of insect control, female mating failure involves mating with a mass-reared, sterilized male, which then results in female reproductive failure. Here, we review female mating failure in the context of SIT at two stages. First, at the pre-copulatory stage we consider factors that affect female mating failure with sterile males, such as differences between sterile and wild males in terms of male courtship success, male discrimination of females, pheromone production, and dispersal. We emphasize studies with some degree of ecological realism and review certain factors that can affect female sexual development and choice, such as diet, age, and sex ratio. Second, at the post-copulatory stage we consider factors that functionally result in female reproductive failure, such as ejaculate transfer and control of female remating. Sterile insect technique operations strive to incorporate methods that increase wild female mating with sterile males so that ultimately population-wide reproductive failure is achieved in the target species. [ABSTRACT FROM AUTHOR]

The codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) is a serious pest of pome fruit worldwide. In an effort to reduce the use of pesticides to control this pest, the sterile insect technique (SIT) is used or considered for use as a component of area-wide integrated pest management programmes. Rearing codling moths through diapause has been shown to improve the competitiveness of sterile moths released in orchards, and provides management alternatives that would allow mass-rearing facilities to increase their yearly production of sterile moths. Because radiosensitivity in insects can be influenced by numerous biological factors, laboratory tests were conducted to examine whether the response to increasing doses of radiation, as expressed in the fecundity and fertility of cohorts of moths, is similar for adult moths mass-reared through diapause or through standard (non-diapause) production protocols. Our data revealed that the effect of increasing doses of radiation on fecundity and fertility of codling moths reared through both rearing strategies was similar. In the case of fertility, this is a particularly important finding for the expanded application of codling moth SIT. If mass-rearing facilities use year-round diapause rearing, the dose required to treat the insects prior to release will be similar to that used when codling moths are reared through standard production protocols. [ABSTRACT FROM AUTHOR]

The codling moth Cydia pomonella (L.) (Lepidoptera Tortricidae) is a key pest of pome fruit (apple, pear and quince) and walnut orchards in most temperate regions of the world. Efforts to control the codling moth in the past mostly relied on the use of broad spectrum insecticide sprays, which has resulted in the development of insecticide resistance, and the disruption of the control of secondary pests. In addition, the frequent reliance and use of these insecticides are a constant threat to the environment and human health. Consequently, there have been increased demands from the growers for the development of codling moth control tactics that are not only effective but also friendly to the environment. In that respect, the sterile insect technique (SIT) and its derivative, inherited sterility (IS), are, together with mating disruption and granulosis virus, among the options that offer great potential as cost-effective additions to available control tactics for integration in area-wide integrated pest-management approaches. In support of the further development of the SIT/IS for codling moth control, the Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture implemented a 5-year Coordinated Research Project (CRP) entitled ‘Improvement of codling moth SIT to facilitate expansion of field application’. Research focussed on sterile codling moth quality and management (e.g. mobility and life-history traits in relation to rearing strategy, dispersal, flight ability, radiosensitivity and mating compatibility) and a better understanding of the basic genetics of codling moth to assist the development of genetic sexing strains (e.g. cytogenetics, the development of dominant conditional lethal mutations, molecular characterization of the sex chromosomes, sex identification in embryos and cytogenetic markers). The results of the CRP are presented in this special issue. [ABSTRACT FROM AUTHOR]

A new culture method for lesser mealworm, Alphitobius diaperinus (Panzer), was developed to provide large numbers of adult lesser mealworms of approximately the same age for insecticide resistance testing. Culturing entailed allowing 100 adults to reproduce for 4 days in a wheat-based culture medium contained inside a plastic culture box, removing the adults from the medium, and then rearing their progeny to adulthood therein, in approximately 56 days at 32°C and 55% RH. During their development, progeny were supplied water via apple slices at 0, 21 and 35 days, and a foam substrate in which to pupate, also at 35 days. During 2004–2005, adult lesser mealworms were collected from six broiler-house populations and then cultured with this method. Each population produced 4500 adults required to complete resistance testing with one insecticide within ten culture boxes, at an average of 798 adults per culture box. [ABSTRACT FROM AUTHOR]