Necrobia rufipes (De Geer): an emerging pest associated with pet store chain in Europe: Presentation

Necrobia rufipes is a cosmopolitan pest, causing considerable damage to stored commodities such as copra (dried coconut), cheese, dried fish, ham. The present study was undertaken to investigate the occurrence of these insects on pet store chain in Europe. In the last year N. rufipes was found associated with pet food, especially in Mediterranean countries, causing considerable economic damage and loss of product. The causes of such sudden diffusion are not known but some considerations are reported. Future studies will be needed to collect data on development on pet food and on the possibility to monitor N. rufipes in wharehouses and pet stores.?Necrobia rufipes is a cosmopolitan pest, causing considerable damage to stored commodities such as copra (dried coconut), cheese, dried fish, ham. The present study was undertaken to investigate the occurrence of these insects on pet store chain in Europe. In the last year N. rufipes was found associated with pet food, especially in Mediterranean countries, causing considerable economic damage and loss of product. The causes of such sudden diffusion are not known but some considerations are reported. Future studies will be needed to collect data on development on pet food and on the possibility to monitor N. rufipes in wharehouses and pet stores.

Combination of mating disruption and parasitoid Habrobracon hebetor against Plodia interpunctella in a chocolate factory: Presentation

A field experiment of 4 years’ duration was carried out to evaluate the efficacy of combining the mating disruption (MD) formulation Dismate ZETA (9Z,12E-tetradecadienyl acetate), with the parasitoid Habrobracon hebetor against the Indianmeal moth Plodia interpunctella in a chocolate factory. The experimental period began early in 2011 and ended in late 2014. Begane Dismate dispensers were placed in the facility from 2011 to 2014 and H. hebetor was released in 2014. Pheromone-baited traps were used to monitor the flight activity of the male moths and oviposition Petri dish cups were placed to assess the progeny production of P. interpunctella females. Following the start of MD, a decrease in the number of P. interpunctella males caught in monitoring traps was observed from 2011 to 2013. A further decline in the moth population was noted in 2014, when MD was combined with the release of parasitoids. The presence of larvae in the oviposition cups was occasionally observed throughout the monitoring period, from 2011 to 2014. This study demonstrates that the combined system of MD and parasitoids is an effective and reliable technique that can be used to successfully control P. interpunctella.A field experiment of 4 years’ duration was carried out to evaluate the efficacy of combining the mating disruption (MD) formulation Dismate ZETA (9Z,12E-tetradecadienyl acetate), with the parasitoid Habrobracon hebetor against the Indianmeal moth Plodia interpunctella in a chocolate factory. The experimental period began early in 2011 and ended in late 2014. Begane Dismate dispensers were placed in the facility from 2011 to 2014 and H. hebetor was released in 2014. Pheromone-baited traps were used to monitor the flight activity of the male moths and oviposition Petri dish cups were placed to assess the progeny production of P. interpunctella females. Following the start of MD, a decrease in the number of P. interpunctella males caught in monitoring traps was observed from 2011 to 2013. A further decline in the moth population was noted in 2014, when MD was combined with the release of parasitoids. The presence of larvae in the oviposition cups was occasionally observed throughout the monitoring period, from 2011 to 2014. This study demonstrates that the combined system of MD and parasitoids is an effective and reliable technique that can be used to successfully control P. interpunctella

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

Hydrolytic Profile of the Culturable Gut Bacterial Community Associated With Hermetia illucens

Larvae of the black soldier fly (BSF) Hermetia illucens (L.) convert organic waste into high valuable insect biomass that can be used as alternative protein source for animal nutrition or as feedstock for biodiesel production. Since insect biology and physiology are influenced by the gut microbiome, knowledge about the functional role of BSF-associated microorganisms could be exploited to enhance the insect performance and growth. Although an increasing number of culture-independent studies are unveiling the microbiota structure and composition of the BSF gut microbiota, a knowledge gap remains on the experimental validation of the contribution of the microorganisms to the insect growth and development. We aimed at assessing if BSF gut-associated bacteria potentially involved in the breakdown of diet components are able to improve host nutrition. A total of 193 bacterial strains were obtained from guts of BSF larvae reared on a nutritious diet using selective and enrichment media. Most of the bacterial isolates are typically found in the insect gut, with major representatives belonging to the Gammaproteobacteria and Bacilli classes. The hydrolytic profile of the bacterial collection was assessed on compounds typically present in the diet. Finally, we tested the hypothesis that the addition to a nutritionally poor diet of the two isolates Bacillus licheniformis HI169 and Stenotrophomonas maltophilia HI121, selected for their complementary metabolic activities, could enhance BSF growth. B. licheniformis HI169 positively influenced the larval final weight and growth rate when compared to the control. Conversely, the addition of S. maltophilia HI121 to the nutritionally poor diet did not result in a growth enhancement in terms of larval weight and pupal weight and length in comparison to the control, whereas the combination of the two strains positively affected the larval final weight and the pupal weight and length. In conclusion, we isolated BSF-associated bacterial strains with potential positive properties for the host nutrition and we showed that selected isolates may enhance BSF growth, suggesting the importance to evaluate the effect of the bacterial administration on the insect performance

Destabilization of the Bacterial Interactome Identifies Nutrient Restriction-Induced Dysbiosis in Insect Guts

Stress-associated dysbiosis of microbiome can have several configurations that, under an energy landscape conceptual framework, can change from one configuration to another due to different alternating selective forces. It has been proposed—according to the Anna Karenina Principle—that in stressed individuals the microbiome are more dispersed (i.e., with a higher within-beta diversity), evidencing the grade of dispersion as indicator of microbiome dysbiosis. We hypothesize that although dysbiosis leads to different microbial communities in terms of beta diversity, these are not necessarily differently dispersed (within-beta diversity), but they form disrupted networks that make them less resilient to stress. To test our hypothesis, we select nutrient restriction (NR) stress that impairs host fitness but does not introduce overt microbiome selectors, such as toxic compounds and pathogens. We fed the polyphagous black soldier fly, Hermetia illucens, with two NR diets and a control full-nutrient (FN) diet. NR diets were dysbiotic because they strongly affected insect growth and development, inducing significant microscale changes in physiochemical conditions of the gut compartments. NR diets established new configurations of the gut microbiome compared to FN-fed guts but with similar dispersion. However, these new configurations driven by the deterministic changes induced by NR diets were reflected in rarefied, less structured, and less connected bacterial interactomes. These results suggested that while the dispersion cannot be considered a consistent indicator of the unhealthy state of dysbiotic microbiomes, the capacity of the community members to maintain network connections and stability can be an indicator of the microbial dysbiotic conditions and their incapacity to sustain the holobiont resilience and host homeostasis

Mechanical Processing of Hermetia illucens Larvae and Bombyx mori Pupae Produces Oils with Antimicrobial Activity

The aim of this work was to develop processing methods that safeguard the quality and antimicrobial properties of H. illucens and B. mori oils. We adopted a vegetable diet for both insects: leftover vegetables and fruit for H. illucens and mulberry leaves for B. mori. First, alternative techniques to obtain a good oil extraction yield from the dried biomass of H. illucens larvae were tested. Traditional pressing resulted to be the best system to maximize the oil yield and it was successfully applied to B. mori pupae. Oil quality resulted comparable to that obtained with other extraction methods described in the literature. In the case of B. mori pupae, different treatments and preservation periods were investigated to evaluate their influence on the oil composition and quality. Interestingly, agar diffusion assays demonstrated the sensitivity of Gram-positive Bacillus subtilis and Staphylococcus aureus to H. illucens and B. mori derived oils, whereas the growth of Gram-negative Pseudomonas aeruginosa and Escherichia coli was not affected. This study confirms that fat and other active compounds of the oil extracted by hot pressing could represent effective antimicrobials against bacteria, a relevant result if we consider that they are by-products of the protein extraction process in the feed industry

Climate and landscape composition explain agronomic practices, pesticide use and grape yield in vineyards across Italy

Context Worldwide, organic farming is being promoted as one of the main alternatives to intensive conventional farming. However, the benefits of organic agriculture are still controversial and need to be tested across wide environmental gradients. Objective Here, we carried out an observational study to test how agronomic practices, pest management, environmental impact and yield of conventional and organic vineyards changed along wide climatic and landscape gradients across Italy. Methods We used a block design with 38 pairs of conventional and organic vineyards across Italy. Results and conclusions Most agronomic practices did not differ between conventional and organic vineyards. By contrast, landscape composition and climate were strong predictors of management in both systems. First, increasing semi-natural areas around the vineyards reduced pesticide pressure and related environmental impacts, but was also associated with lower yield. Second, irrespective of the farming system, a warm and dry climate was associated with reduced fungicide pressure. Conventional farming had a yield gain of 40% in cold and wet climate compared to organic but the yield gap disappeared in the warmest regions. Significance In both farming systems, we observed a large variability in management practices that was mainly explained by climate and landscape composition. This large variability should be considered when evaluating the benefits and drawbacks of different farming systems under contrasting environmental contexts

Customer complaints about insect contaminated ready meals: Presentation

More than one-hundred food complaints about ready meals, coming from mass catering, were analyzed from 2003 to 2017. Even if insects in meals have an enormous negative impact on customers, the percentage relevance, considering the long period and the number of meals served, is negligible. Coleoptera (34%) was the most represented order, followed by Lepidoptera (27%), and Diptera (23%). Coleoptera insects were mainly field pests, found in salads and spinach, moths were represented by species infesting vegetables (58%) and by stored product pests (42%). Species of hygienic concern were found in Diptera. Few cases of cockroach contamination were reported on different food, but it is important to underline their presence in the meal, as it indicates a heavy environmental infestation and a high hygienic risk.More than one-hundred food complaints about ready meals, coming from mass catering, were analyzed from 2003 to 2017. Even if insects in meals have an enormous negative impact on customers, the percentage relevance, considering the long period and the number of meals served, is negligible. Coleoptera (34%) was the most represented order, followed by Lepidoptera (27%), and Diptera (23%). Coleoptera insects were mainly field pests, found in salads and spinach, moths were represented by species infesting vegetables (58%) and by stored product pests (42%). Species of hygienic concern were found in Diptera. Few cases of cockroach contamination were reported on different food, but it is important to underline their presence in the meal, as it indicates a heavy environmental infestation and a high hygienic risk