ACCIDENTAL INTRODUCTION IN ITALY OF THE PARASITOIDSPATHIUS VULNIFICUSWILKINSON (HYMENOPTERA BRACONIDAE DORYCTINAE)

This paper reports the finding of the Hymenoptera Doryctinae Spathius vulnificusWilkinson for the first time inEurope. This is an idiobiont ectoparasitoid attacking woodborer larvae of some Bostrichidae (Coleoptera) species. Suchexotic parasitoid, mainly spread in the Oriental and southeastern part of the Palaeartic Region, has been intercepted inassociation with the lesser auger beetle Heterobostrychusaequalis (Waterhouse)(Coleoptera, Bostrichidae), importedfrom the Asian Far East in wood packaging material. This report represents an updating on the worldwide distribution ofthe parasitoid

Rice fields as a hot spot of water beetles (Coleoptera Adephaga and Polyphaga)

The study is representative of wetlands subjected to strong anthropogenic impact as rice fields are. The aquatic Coleoptera have been collected monthly from channels, rice fields and a natural spring for one year, resulting in 31 species belonging to 8 families (Brachyceridae, Dytiscidae, Dryopidae, Elmidae, Gyrinidae, Haliplidae, Helophoridae, Hydrophilidae) which have been identified, 19 of which in rice paddies. The comparison of paddies subjected to different anthropogenic impacts shows that the flooding period is only one of the factors influencing the community of water beetles. Important information on the occurrence of the species during the year is also provided and adds to the few knowledge present in the literature. All the data, as well as the detection of vulnerable and rare species, evidence that rice agro-ecosystems are essential for the exploitation of water beetle biodiversity in areas densely colonized, industrialized and cultivated, where wetlands has strongly reduced over the last centuries

Nutrient recapture from insect farm waste: Bioconversion with hermetia illucens (L.) (Diptera: Stratiomyidae)

Hermetia illucens is an ecient bioconverter able to grow on various dierent organic materials, producing larvae, which are a good source of protein and fat with applications in the animal feed and biochemical industries. This fly's capacity to reduce huge amounts of waste presents an interesting opportunity to establish a circular food economy. In this study, we assessed the suitability of using organic wastes from cricket and locust farming to rear H. illucens. Larvae developed until adult emergence on all the wastes, with a mean survival of over 94%. Cricket waste allowed faster development of heavier larvae than locust waste. Substrate reduction was particularly interesting on cricket waste ( < 72%), while locust waste was only reduced by 33%. The nutritional composition of the larvae reflected that of the growing substrates with a high protein and fat content. These results demonstrate the potential of using H. illucens to reduce and valorise waste generated when farming various insects through the production of a larval biomass for use as a protein meal in animal feeds or industrial applications

How many cooperators are too many? Foundress number, reproduction and sex ratio in a quasi-social parasitoid

In the parasitoid genus Sclerodermus, multiple foundresses produce and care for communal broods on large hosts, which can lead to greater reproductive success for group members than attempting to reproduce alone. We explore the consequences of foundress group size on the benefits of cooperative brooding and on brood sex ratios by providing groups of 10-55 foundresses with a single host and no alternative reproductive options. Within this range, increasing foundress group size leads to increasingly common failure in brood production and diminished per capita success. Group production of adult offspring declines once foundress number reaches around 25. Brood failure is usually at the early developmental stages, and current evidence suggests that there may be competition among foundresses for oviposition sites, possibly involving reproductive dominance and ovicide, which also delays initial brood production. Once broods become established, their rate of development is enhanced by large foundress numbers. The sex ratios of broods are very strongly female biased, irrespective of the foundress number. As this bias is not easily explained by standard models of local mate competition or by a recent model of local resource enhancement, we suggest an explanation based on control of sex allocation by a minority of dominant foundresses, which monopolise the production of adult males.Peer reviewe

Factors affecting the reproduction and mass-rearing of sclerodermus brevicornis (Hymenoptera: Bethylidae), a natural enemy of exotic flat-faced longhorn beetles (Coleoptera: Cerambycidae: Lamiinae)

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Many species of long-horned beetles are invasive pests causing significant economic damage in agro-forestry systems. They spend the majority of their life-cycle concealed inside natural wood or wooden packaging materials and are largely protected from adverse environmental conditions and pesticide sprays. Biological control via parasitoid natural enemies including members of the bethylid genus Sclerodermus, has proven effective against some long-horned beetles that are invasive in China. In Europe, the biocontrol potential of native Sclerodermus species is being evaluated with a view to developing efficient mass-rearing techniques and then actively deploying them against invasive Asian beetles. Here, we continue evaluations of S. brevicornis by establishing that groups of females that have already reared offspring to emergence are capable of reproducing subsequent hosts and by evaluating the lifetime reproductive capacity of individual females provided with successive hosts. Additionally, we assess the laboratory shelf-life of adult females stored for different times at different temperatures including cold storage, and then assess the post-storage reproductive performance of groups of females provided with a single host. We found that adult female longevity declines with increasing storage temperature and that most aspects of subsequent performance are negatively affected by high temperatures. The adaptability to low temperature storage enhances the suitability of S. brevicornis to mass-rearing programs and thus biocontrol deployment

Kinship effects in quasi-social parasitoids I: Co-foundress number and relatedness affect suppression of dangerous hosts

© 2020 The Linnean Society of London, Biological Journal of the Linnean Society, 2020, 130, 627-641 Explanations for the highest levels of sociality typically invoke the concept of inclusive fitness. Sclerodermus, a genus of parasitoid hymenopterans, is quasi-social, exhibiting cooperative brood care without generational overlap or apparent division of labour. Foundress females successfully co-exploit hosts that are too large to suppress when acting alone and the direct fitness benefits of collective action may explain their cooperation, irrespective of kinship. However, cooperation in animal societies is seldom free of conflicts of interest between social partners, especially when their relatedness, and thus their degree of shared evolutionary interests, is low. We screened components of the life-history of Sclerodermus brevicornis for effects of varying co-foundress number and relatedness on cooperative reproduction. We found that the time taken to paralyse standard-sized hosts is shorter when co-foundress number and/or relatedness is higher. This suggests that, while females must access a paralysed host in order to reproduce, individuals are reluctant to take the risk of host attack unless the benefits will be shared with their kin. We used Hamilton's rule and prior data from studies that experimentally varied the sizes of hosts presented to congeners to explore how the greater risks and greater benefits of attacking larger hosts could combine with relatedness to determine the sizes of hosts that individuals are selected to attack as a public good. From this, we predict that host size and relatedness will interact to affect the timing of host paralysis; we test this prediction in the accompanying study

Kinship effects in quasi-social parasitoids II: Co-foundress relatedness and host dangerousness interactively affect host exploitation

© 2020 The Linnean Society of London, Biological Journal of the Linnean Society, 2020, 130, 642-660 Sclerodermus brevicornis is a parasitoid that exhibits cooperative multi-foundress brood production. Prior work showed that the time lag to paralysis of small-sized hosts is shorter when co-foundress relatedness is higher and predicted that the greater risks and greater benefits of attacking larger hosts would combine with co-foundress relatedness to determine the limits to the size of a host that a female is selected to attack as a public good. It was also predicted that the time to host attack would be affected by an interaction between host size and relatedness. Here, we show empirically that both host size and kinship affect S. brevicornis reproduction and that they interact to influence the timing of host attack. We also find effects of co-foundress relatedness after hosts have been suppressed successfully. A public goods model using parameters estimated for S. brevicornis again suggests that selection for individual foundresses to attack and, if successful, to share hosts will be dependent on both the size of the host and the relatedness of the foundresses to any co-foundresses present. Females will not be selected to bear the individual cost of a public good when hosts are large and dangerous or when their relatedness to the co-foundress is low. We conclude that although reproductive behaviours exhibited by Sclerodermus females can be cooperative, they are unlikely to be exhibited without reference to kinship or to the risks involved in attempting to suppress and share large and dangerous hosts

A key for the identification of larvae of Anoplophora chinensis, Anoplophora glabripennis and Psacothea hilaris (Coleoptera Cerambycidae Lamiinae) in Europe

Anoplophora chinensis (Förster), A. glabripennis (Motschulsky) and Psacothea hilaris (Pascoe) (Coleoptera Cerambycidae Lamiinae) are longhorned beetles native to the far eastern regions of Asia and were recently accidentally introduced into Europe. The three exotic species are harmful insects to broadleaved plant species, and much attention is being paid to prevent further introductions and spread in the European Union. Severe phytosanitary measures are applied with the aim of eradicating outbreaks of the pests. Crucial for control is rapid identification of the longhorned species during phytosanitary inspections, both in entry ports and in the rest of the territory of the European Union. Taxonomic keys and descriptions of the adult morphology are available in the literature, but there are significant gaps in the taxonomy of larval morphology, and thus molecular analyses are required. During monitoring activities, a practical morphological taxonomic key would be a rapid and useful tool for species identification of the larvae. In the present work, a taxonomic key provided with detailed morphological pictures is proposed for the identification of the larvae of the three exotic species A. chinensis, A. glabripennis and P. hilaris among the closely related species of the native fauna of Europe

Performance of Sclerodermus brevicornis, a parasitoid of invasive longhorn beetles, when reared on rice moth larvae

© 2020 The Netherlands Entomological Society Biological control efficiency can be improved by developing effective mass-rearing systems to produce large numbers of high-quality parasitoids. This study explored an alternative host for rearing Sclerodermus brevicornis (Kieffer) (Hymenoptera: Bethylidae), a potential biocontrol agent for the suppression of exotic and invasive wood-boring longhorn beetle (Coleoptera: Cerambycidae) populations in the European agroforestry ecosystems. We tested larvae of the rice moth, Corcyra cephalonica Stainton (Lepidoptera: Pyralidae), as host for the parasitoid. We quantified the probability and timing of host attack and parasitism as well as reproductive success, offspring production, and the characteristics of adult offspring. As S. brevicornis is a quasi-social species (multiple females, communally produced offspring broods), we also explored the effects of varying the number of females to which individual hosts were presented, with the aim of determining the optimal female-to-host ratio. As time to host attack can be a limiting factor in S. brevicornis rearing protocols, we tested the use of adult females of another bethylid species, Goniozus legneri Gordh, to paralyse C. cephalonica larvae prior to presentation. We identified the conditions within our experiment that maximized offspring production per host and offspring production per adult female parasitoid. We found that C. cephalonica is suitable as a factitious host and, as it is considerably more straightforward for laboratory rearing than cerambycid species, it is a good candidate for adoption by future S. brevicornis mass-rearing and release programmes