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Plastic waste has recently become a major global environmental concern and one of the biggest challenges has been seeking for alternative management options. Several studies have revealed the potential of several coleopteran species to degrade plastics, and this is the first research paper on plastic-degradation potential by lesser mealworms from Africa. This study evaluated the whole mitogenomic profile of the lesser mealworm to further identify the insect. The ability of the mealworm to consume Polystyrene (PS) was also evaluated alongside its associated gut microbiota diversity. Our results showed a complete circular mitochondrial genome which clustered closely to the Alphitobius genus but also suggested that our insect might be a new subspecies which require further identification. During the PS feeding trials, overall survival rates of the larvae decreased when fed a sole PS diet while PS intake was observed to increase over a 30-day period. The predominant bacteria observed in larvae fed PS diets were Kluyvera, Lactococcus, Klebsiella, Enterobacter, and Enterococcus, while Stenotrophomonas dominated the control diet. These findings demonstrated that the newly identified lesser mealworm can survive on a PS diet and has a consortium of important bacteria strongly associated with PS degradation. This work provides a better understanding of bioremediation applications, paving the way for further research into the metabolic pathways of plastic-degrading microbes and bringing hope to solving plastic waste pollution while providing high-value insect protein towards a circular economy. [ABSTRACT FROM AUTHOR]

Abstract Plastic waste has recently become a major global environmental concern and one of the biggest challenges has been seeking for alternative management options. Several studies have revealed the potential of several coleopteran species to degrade plastics, and this is the first research paper on plastic-degradation potential by lesser mealworms from Africa. This study evaluated the whole mitogenomic profile of the lesser mealworm to further identify the insect. The ability of the mealworm to consume Polystyrene (PS) was also evaluated alongside its associated gut microbiota diversity. Our results showed a complete circular mitochondrial genome which clustered closely to the Alphitobius genus but also suggested that our insect might be a new subspecies which require further identification. During the PS feeding trials, overall survival rates of the larvae decreased when fed a sole PS diet while PS intake was observed to increase over a 30-day period. The predominant bacteria observed in larvae fed PS diets were Kluyvera, Lactococcus, Klebsiella, Enterobacter, and Enterococcus, while Stenotrophomonas dominated the control diet. These findings demonstrated that the newly identified lesser mealworm can survive on a PS diet and has a consortium of important bacteria strongly associated with PS degradation. This work provides a better understanding of bioremediation applications, paving the way for further research into the metabolic pathways of plastic-degrading microbes and bringing hope to solving plastic waste pollution while providing high-value insect protein towards a circular economy.

The effect of the particle size of the feed on the larval growth and feed utilization parameters of two mealworm species, Alphitobius diaperinus (Panzer) and Tenebrio molitor L. (Coleoptera: Tenebrionidae), was examined under laboratory conditions. Wheat bran of four different particle sizes (100–250, 500–650, 850–1000 and >2000 μm) was provided as feed to larvae of both species. The larval growth and survival, as well as time to pupation and the amount of feed consumed, were monitored to determine differences among the wheat bran particle sizes within each insect species. Our research results suggest that a finely ground feed with a particle size below 650 μm significantly impact the growth and development of A. diaperinus, as opposed to a feed containing particles larger than 850 μm. Contrariwise, the larvae of T. molitor exhibited no discernible response to the various feed particle sizes that were evaluated. Overall, it was observed that the two mealworm species did not exhibit identical responses for the tested feed particle size, suggesting that this factor is species dependent. [ABSTRACT FROM AUTHOR]

The botanical insecticide market is growing because of limitations placed on the use of certain synthetic chemical insecticides. In this sense, the lesser mealworm Alphitobius diaperius (Coleoptera: Tenebrionidae) is the main poultry pest. The insect causes weight loss and damage to the digestive system of poultry, and it is a vector and reservoir of pathogens. Consequently, this study explored the following hypotheses: (i) essential oils (EOs) derived from Mentha spp. are toxic to A. diaperius; (ii) these EOs are compatible with Beauveria bassiana, the natural enemy of the poultry pest, that parasite A. diaperinus; (iii) these EOs also exhibit activity against bacteria that are pathogenic to poultry. In topical applications and ingestion tests, EOs from Mentha arvensis, Mentha spicata, and Mentha piperita were toxic to A. diaperinus. Chromatographic analyses revealed that menthol is the predominant compound in M. arvensis and M. piperita, whereas carvone is the major compound in M. spicata. Both (−)- and (+)-menthol, along with (−)- and (+)-carvone, underwent testing with A. diaperinus. Nevertheless, their activity was not as potent as those of the EOs, suggesting a possible synergistic and/or additive effect. The EOs did not have any adverse effects on the conidial germination, vegetative growth, or conidia production per colony of the entomopathogenic fungus B. bassiana. Consequently, these EOs are compatible with this natural enemy. The EO extracted from M. spicata exhibited significant toxicity against Staphylococcus aureus (ATCC 25923), whereas the remaining EOs displayed moderate toxicity against this bacterium. The EOs derived from Mentha spp., as assessed in this study, hold promise for the development of botanical insecticides tailored for the control of A. diaperinus. These insecticides are selective in favor of the natural enemy B. bassiana and can also serve as effective sanitizers, thanks to their antibacterial properties. [ABSTRACT FROM AUTHOR]

Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), commonly known as the lesser mealworm, is a significant pest that infests stored grains and other amylaceous commodities. In addition, the species has also been recognized as a viable and environmentally friendly protein source. However, there is still a lack of comprehensive research on the developmental response of this species across various temperature and moisture conditions. This study investigates the impact of temperature and moisture content of the commodity on the population growth of the lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae). In the first series of bioassays, the progeny production of A. diaperinus adults was recorded after 50 days of incubation under a range of temperatures from 25 to 40 °C in cracked soft wheat with 11.3% moisture content, while in the second series, the moisture content of the wheat was adjusted to 5, 10, 15, and 20%, at 30 °C. Our results show that temperature largely influences parental adult mortality of A. diaperinus. The most suitable temperatures for optimal larval development and adult survival were found to be within the spectrum of 25 to 32 °C. Moreover, we found that the moisture content of the wheat that served as rearing media was also a factor of significance, since a gradual decrease in the larval numbers was observed with an increase in the moisture content. The findings of this study provide data to further enhance the pest control strategies of A. diaperinus in poultry farms but also to establish mass rearing standards and facilitate the production of the species for efficient use as food and feed. [ABSTRACT FROM AUTHOR]

During the processing of insects for food and feed applications, thermal treatments are often used for decontamination purposes. However, these treatments denature proteins comprising their functional properties. Milder methods for microbiological decontamination can be used, such as microfiltration. Therefore, in this study dead-end microfiltration (0.2 µm poly-ethersulphone membrane) was tested for decontamination of soluble fractions of lesser mealworms and house crickets obtained at pH values of 3 and 8. The results showed that deadend microfiltration was successful in the removal of microorganisms (total viable count), removing the need for thermal treatments for the permeates. Protein recovery in the permeate was relatively low (14-43 %). Lesser mealworms at pH 3 gave the highest protein recovery in the permeate (43 %), as explained by the activity of endogenous proteases producing soluble peptides during microfiltration. Confocal imaging showed that the efficiency of microfiltration was reduced by membrane fouling caused by protein aggregation. The presence of lipids in the pre-filtrate does not hamper the permeate protein recovery. In conclusion, dead-end microfiltration with a 0.2 µm membrane is successful in achieving microbial stability. A pH of 3 is recommended during the extraction process to obtain a higher protein recovery. [ABSTRACT FROM AUTHOR]

Simple Summary: This study evaluated the minimum as well as the maximum label dose of d-tetramethrin plus acetamiprid applied on plastic, glass, metal, wood, and ceramic surfaces, against adults of both species, in terms of immediate and delayed mortality. All T. molitor died after a 7-day exposure to the maximum dose at all tested surfaces when food was absent. In the presence of food, only glass-, metal-, and ceramic-treated surfaces killed all adults at the same dose. Even the minimum dose provided 100% mortality on glass, metal, and ceramic surfaces in both food scenarios. In the case of A. diaperinus, only the maximum dose caused the death of all exposed individuals on glass (with food) and on glass and plastic (no food). Overall, the maximum dose of d-tetramethrin plus acetamiprid is effective against the tested species on certain types of surfaces. Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae) are two common tenebrionids occurring in grain storages. In this study, we assessed the immediate and delayed mortalities caused by d-tetramethrin plus acetamiprid on five different surfaces, i.e., plastic, glass, metal, wood, and ceramic, against adults of the two species. The tests included two label doses of the insecticide (minimum and maximum) and two food scenarios (food and no food). Generally, the maximum dose was more efficient than the minimum dose, and the presence of food resulted in lower observed mortalities than when food was absent. Tenebrio molitor was more susceptible than A. diaperinus, at all dose, food, and surface scenarios. At delayed bioassays, both doses killed all T. molitor on plastic, while on wood, mortality ranged between 80.6 and 100.0%, regardless of the food scenario. Concerning A. diaperinus, delayed mortalities ranged among treated surfaces, food scenarios, and dose from 58.3 to 100.0%. The insecticide killed the most individuals when it was treated on glass, while when it was applied on wood caused the death of the least individuals. Concerning plastic, metal, and ceramic surfaces, no general trend was observed. The maximum dose of the tested insecticide provides elevated mortalities for both species when food is absent. [ABSTRACT FROM AUTHOR]

The lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), is an important pest of stored products and at the same time a species with great potential as food and feed that has recently attracted increasing interest as nutrient source. Future predictions show a massive increase of insect meals' production in the near future, therefore, as expected in the case of other durable stored products, insect meals may get infested by insects during their storage. In this context and as a continuance of our previous study on the susceptibility of meal of the yellow mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae), to storage insect infestations, the objective of this study was to test the susceptibility of A. diaperinus meals to infestations of three stored products pests, namely A. diaperinus itself, T. molitor , and the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). The population growth of the three species was evaluated on pure A. diaperinus meal, as well as on A. diaperinus meal-based substrates with different percentages of wheat bran (0, 25, 50, 90, and 100% bran). Our results showed that all three insect species tested were able to grow and develop on the A. diaperinus meal-based substrates evaluated, giving in a short time high population densities. This study confirms again our initial theory for insect infestations during storage of insect-based products. [ABSTRACT FROM AUTHOR]

Stored-product commodities are attacked by numerous insect species. The adulticidal effects of entomopathogenic nematodes (EPNs) on grains remain uninvestigated. Thus, in the current study, seven doses of the EPNs Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), Steinernema carpocapsae (Weiser) (Rhabditida: Steinernematidae), and Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) were inoculated on wheat kernels against adults of Trogoderma granarium Everts (Coleoptera: Dermestidae), Tenebrio molitor L. (Coleoptera: Tenebrionidae), and Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae). Complete mortality (100.0%) of T. granarium was recorded after exposure for eight days to the highest dose of 50,000 Infective Juveniles/mL (IJs/mL) of all tested EPN species. At the same exposure interval, 62.2%, 85.6%, and 76.7% of T. molitor were killed by 50,000 IJs/mL of H. bacteriophora, S. carpocapsae, and S. feltiae, respectively. The highest mortality of A. diaperinus (11.1%) was documented eight days post-exposure to 50,000 IJs/mL of H. bacteriophora. In general, T. granarium was highly susceptible, followed by T. molitor and A. diaperinus. Concerning EPN species, S. carpocapsae exhibited the highest insecticidal capacity, followed by S. feltiae and H. bacteriophora. Trogoderma granarium and T. molitor can be sufficiently managed by the highest dose of 50,000 IJs/mL of all three EPNs and by S. carpocapsae, respectively. However, A. diaperinus was not affected by any EPNs. [ABSTRACT FROM AUTHOR]

Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), commonly known as the lesser mealworm, is a significant pest that infests stored grains and other amylaceous commodities. In addition, the species has also been recognized as a viable and environmentally friendly protein source. However, there is still a lack of comprehensive research on the developmental response of this species across various temperature and moisture conditions. This study investigates the impact of temperature and moisture content of the commodity on the population growth of the lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae). In the first series of bioassays, the progeny production of A. diaperinus adults was recorded after 50 days of incubation under a range of temperatures from 25 to 40 °C in cracked soft wheat with 11.3% moisture content, while in the second series, the moisture content of the wheat was adjusted to 5, 10, 15, and 20%, at 30 °C. Our results show that temperature largely influences parental adult mortality of A. diaperinus. The most suitable temperatures for optimal larval development and adult survival were found to be within the spectrum of 25 to 32 °C. Moreover, we found that the moisture content of the wheat that served as rearing media was also a factor of significance, since a gradual decrease in the larval numbers was observed with an increase in the moisture content. The findings of this study provide data to further enhance the pest control strategies of A. diaperinus in poultry farms but also to establish mass rearing standards and facilitate the production of the species for efficient use as food and feed.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on frozen and dried formulations from whole lesser mealworm (Alphitobius diaperinus larva) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The term lesser mealworm refers to the larval form of the insect species Alphitobius diaperinus. The NF comprises the frozen and freeze-dried formulations of the lesser mealworm as whole or in the form of a paste or powder. Apart from water in the frozen formulations (whole, paste), the main components of the NF are crude protein and fat, besides smaller amounts of digestible carbohydrates and fibre (chitin). The Panel notes that the levels of contaminants in the NF depend on the concentration of such substances in the insect feed. The Panel notes furthermore that the true protein levels in the NF are overestimated when using the nitrogen-to-protein conversion factor of 6.25, due to the presence of non-protein nitrogen from chitin. The applicant proposed to use the NF formulations added as an ingredient to various food products such as cereal bars, pasta, meat imitates and bakery products. The target population is the general population. Additionally, the applicant proposed to use the NF as a food supplement in adults. The Panel notes that, considering that the NF will not be the sole source of dietary protein, and the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous. The submitted subchronic 90-day toxicity study with the NF as testing material did not raise safety concerns. The Panel considers that the consumption of the NF may induce primary sensitisation and allergic reactions to lesser mealworm proteins and may cause allergic reactions in subjects with allergy to crustaceans and dust mites. Additionally, allergens from the feed may end up in the NF. Allergenicity aside, the Panel concludes that the NF is safe under the proposed uses and use levels. [ABSTRACT FROM AUTHOR]

During the last decade, insects have shown up as a promising answer to the increasing animal protein demand for a continuously growing human population. A wide spectrum of substrates of plant origin can be currently used as insect feed; the sustainability of insect rearing though greatly increases when organic side-streams and wastes are valorized and upcycled through their bioconversion with insects. Additionally, the exploitation of low-cost organic residues as insect feed can also significantly suppress the rearing cost and, consequently, the price of the insect meal. In this context, the aim of our work was to evaluate organic side-streams, generated through several agro-industrial processes, as feeding substrates for the larvae of the lesser mealworm, Alphitobius diaperinus. In a laboratory trial, eleven agricultural side-streams were provided to larvae singly to assess their potential to support complete larval development, whereas in the second trial, larvae were fed two groups of isoproteinic diets consisting of the side-streams that performed well in the first trial. Our results showed the suitability of several agricultural side-streams as feed for A. diaperinus larvae, e.g., barley by-products (classes I and II), sunflower meal, cotton cake and oat sidestream, which, when fed singly, efficiently supported larval growth, resulting in high survival rates and final larval weights, comparable to the control. Similarly, several of the side-streams-based diets tested were shown to be suitable for A. diaperinus rearing. These results aim to contribute to the utilization of agricultural side-streams singly or in composed diets for the rearing of A. diaperinus larvae. [ABSTRACT FROM AUTHOR]

[Display omitted] • Insect residues can be biotransformed by lactic acid bacteria without a carbon source. • Deproteinization of 29 % achieved after 120 h of incubation by L. brevis. • Lactic acid bacteria biomass increased by 2 log 10 CFU/mL in only 48 h. • Biotransformation led to the formation of peptides with antioxidant activity. Processing of edible insects typically involves fractionating into high-value food ingredients, which results in by-products containing chitin and insoluble proteins. This study examined the effectiveness of lactic acid bacteria (LAB) in removing proteins from chitin in insect processing residues. Lesser mealworm processing residues were biologically treated for 48 and 120 h using LAB strains without added carbon sources. Results showed partial deproteinization, up to 29 % with Levilactobacillus brevis after 120 h. Most LAB grew up to 2 log 10 colony-forming units/mL in the first 48 h. Confocal microscopy and Fourier-transform infrared spectra indicated that some protein remained attached to chitin. The molecular weight of solubilized proteins was affected by strain and time of incubation, with antioxidant activity increasing significantly after 120 h with Lacticaseibacillus paracasei. The biological treatment of insect processing streams can be a sustainable approach to producing high amounts of LAB biomass with subsequent protein solubilization and chitin release. [ABSTRACT FROM AUTHOR]

Abstract Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on frozen and dried formulations from whole lesser mealworm (Alphitobius diaperinus larva) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The term lesser mealworm refers to the larval form of the insect species Alphitobius diaperinus. The NF comprises the frozen and freeze‐dried formulations of the lesser mealworm as whole or in the form of a paste or powder. Apart from water in the frozen formulations (whole, paste), the main components of the NF are crude protein and fat, besides smaller amounts of digestible carbohydrates and fibre (chitin). The Panel notes that the levels of contaminants in the NF depend on the concentration of such substances in the insect feed. The Panel notes furthermore that the true protein levels in the NF are overestimated when using the nitrogen‐to‐protein conversion factor of 6.25, due to the presence of non‐protein nitrogen from chitin. The applicant proposed to use the NF formulations added as an ingredient to various food products such as cereal bars, pasta, meat imitates and bakery products. The target population is the general population. Additionally, the applicant proposed to use the NF as a food supplement in adults. The Panel notes that, considering that the NF will not be the sole source of dietary protein, and the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous. The submitted subchronic 90‐day toxicity study with the NF as testing material did not raise safety concerns. The Panel considers that the consumption of the NF may induce primary sensitisation and allergic reactions to lesser mealworm proteins and may cause allergic reactions in subjects with allergy to crustaceans and dust mites. Additionally, allergens from the feed may end up in the NF. Allergenicity aside, the Panel concludes that the NF is safe under the proposed uses and use levels.

Insect production currently involves thermal processes to ensure microbial safety and inactivate endogenous enzymes, but these processes negatively affect the protein's technological properties. Therefore, this study compared high hydrostatic pressure (HHP) at 200/400/600 MPa for 10 min to blanching at 90 °C for 10 min, on soluble protein fractions (pH 3) from house crickets (Acheta domesticus) and lesser mealworms (Alphitobius diaperinus). HHP significantly reduced the microbial load, especially at 400 and 600 MPa. For aerobic counts of mealworms, blanching (from ∼6 to ∼3 log CFU/mL) was more effective than HHP (∼4 log CFU/mL). HHP preserved the secondary protein structure better than blanching, but was less effective in protease inactivation, though only evident in mealworms. HHP did not affect foaming and emulsification properties but improved protein solubility after pH adjustment to 7 compared to untreated fractions by 14–22%. We thus demonstrate that HHP can be an effective alternative to conventional blanching treatments. The emerging edible insect industry is currently struggling with several challenges. Conventional thermal processes that are often applied can negatively affect the techno-functional protein properties. We demonstrated that high hydrostatic pressure (HHP) can be an effective milder alternative to thermal processes. The evaluated blanching condition did not always negatively affect the functional protein properties, and blanching was more effective in protease inactivation compared to HHP for lesser mealworms. HHP can be of industrial relevance for inactivating house cricket fractions with high protein solubility intended for emulsion applications. Blanching could be better suited to provide proteolytically stable fractions. [Display omitted] • Pressure treatment (HHP) increased protein solubility at pH 7 up to 22% vs. untreated • Unlike blanching (90 °C, 10 min), HHP retained emulsion properties for house crickets • Unlike HHP, blanching increased intermolecular β-sheets showing protein aggregation • Proteases in mealworms were inactivated by blanching, and only partially by HHP [ABSTRACT FROM AUTHOR]

Simple Summary: Poultry meat production and consumption continue to grow worldwide; therefore, the safety of poultry products is a priority for consumers, producers, and governing authorities. Thus, it is essential to find an effective solution to maintain proper hygiene in poultry production. One such tool is a water-based slow-release biocidal paint that contains insecticidal and antimicrobial compounds. In this study it was assumed that biocidal paint could be useful in controlling insect pests such as Alphitobius diaperinus and reducing microbiological contamination of air and litter and have a beneficial effect on microclimate in poultry houses. The results suggest that the tested biocidal paint could be an effective alternative to other insecticides and disinfectants. Additionally, the research is of a practical nature and may be very useful for poultry producers in controlling A. diaperinus populations and maintaining proper hygiene in poultry houses. Effective disinfection and disinsection are the keys to successful operation of modern poultry farms and the safety of poultry products. The cleaning and disinfection of poultry houses are important aspects of farm hygiene management. The correct execution of all steps of cleaning, disinfection, and disinsection procedures and the use of appropriate products are crucial for the prevention and control of zoonotic and animal diseases. In this study it was assumed that a water-based slow-release biocidal paint could be useful in controlling insect pests such as Alphitobius diaperinus and reducing microbiological contamination of air and litter in poultry houses and have a beneficial effect on microclimate in poultry houses. Therefore, the locations of A. diaperinus in the poultry houses, the microbiological contamination of air and litter, as well as the microclimatic conditions in the houses and the physicochemical parameters of the litter were evaluated. The results suggest that the tested biocidal paint could be an effective alternative to other insecticides and disinfectants. Additionally, the research is of a practical nature and may be very useful for poultry producers in controlling A. diaperinus populations and maintaining proper hygiene in poultry houses. Further research is needed. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, we used etofenprox, deltamethrin, and the combination of piperonyl butoxide+acetamiprid+d-tetramethrin as surface treatments on concrete (with or without food) to evaluate the short- and long-term mortalities of the lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) small and large larvae. Concerning short-term mortality, etofenprox killed 97.8% and 80.0% of the small and large larvae, respectively, 7 days post-exposure on concrete without food. Deltamethrin caused complete (100.0%) mortality to small larvae without food (3 days post-exposure), small larvae with food, and large larvae without food (5 days post-exposure), and 98.9% mortality to large larvae with food after 5 days of exposure. Piperonyl butoxide+acetamiprid+d-tetramethrin killed all small larvae without food 5 days post-exposure. Concerning long-term mortality, all small larvae exposed to etofenprox died on concrete without food, while piperonyl butoxide+acetamiprid+d-tetramethrin caused 85.0% mortality to small larvae on concrete with food. Overall, deltamethrin was the most efficient active ingredient for the management of both small and large larvae of A. diaperinus. The lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) is an important stored-product pest for the poultry industry as it is a vector of dangerous pathogens for humans. In the present study, we evaluated the short- and long-term mortalities of small and large larvae of A. diaperinus when they were exposed to concrete-covered Petri dishes treated with etofenprox, deltamethrin, and the combination of piperonyl butoxide+acetamiprid+d-tetramethrin. Small and large larvae were exposed to each insecticide applied on concrete surfaces with or without food. The short-term mortality was recorded after 1 day, 3 days, 5 days, and 7 days, while the long-term mortality was recorded 7 days after the transport of the larvae alive to pesticide-free concrete-covered dishes. Regarding short-term mortality levels, 97.8% and 80.0% of the small and large larvae, that were exposed to etofenprox without food, died after 7 days of exposure, respectively. Concerning deltamethrin, all tested small larvae were killed after 3 days (without food) and 5 days (with food) of exposure. For large larvae, deltamethrin caused 98.9% (with food) and 100.0% (without food) mortality levels after 5 days of exposure. The combination of piperonyl butoxide+acetamiprid+d-tetramethrin caused high mortality levels to small larvae, i.e., 84.4% and 100.0% on dishes with and without food, respectively, but low to moderate mortality levels to large larvae that did not exceed 67.8% after 7 days of exposure. Long-term mortality varied vastly among the tested insecticides. Etofenprox killed 100.0% of the small larvae on concrete without food, but 24.0% of the large larvae exposed to concrete containing food. Deltamethrin did not provide long-term mortality to large larvae when food was present. Piperonyl butoxide+acetamiprid+d-tetramethrin caused mortality rates that overall varied from 33.5% (large larvae on concrete with food) to 85.0% (small larvae on concrete with food). In conclusion, deltamethrin killed almost all exposed larvae at exposures of ≤5 days, regardless of their size and the presence of food on the concrete. [ABSTRACT FROM AUTHOR]

Use of edible insects as an alternative source of proteins in food and feed is increasing. These last years, numerous companies in Europe have started producing insects for food and feed purposes. In the European Union, the use of edible insects for human consumption falls within Regulation (EU) No. 2015/2283 on novel foods. For feed, Commission Regulation (EU) 2017/893 authorizes seven insect species as processed animal proteins for aquaculture. Methods of authentication are required to check the conformity of the products. In this study, we propose a real-time polymerase chain reaction (PCR) method for the specific detection of the lesser mealworm (Alphitobius diaperinus), one of the species included in the shortlist of authorized insects. The selected target is the cadherin gene with a single-copy (per haploid genome) illustrated by our experimental evidence. The PCR test amplified a 134-bp fragment of the cadherin gene. The qualitative method was assessed toward several performance criteria. Specificity was checked against 54 insect species next to other animal and plant species. The sensitivity, efficiency, robustness, and transferability of the PCR assay were also successfully tested. Finally, the applicability of the test was assessed on real-life processed samples (industrial meals) of A. diaperinus. The study also showed that there seems to be a huge confusion on the correct labeling of the marketed mealworms. We did not succeed to get Alphitobius laevigatus samples. They all appeared to belong to the A. diaperinus taxon.

Water-in-oil-in-water (W1/O/W2) emulsions are complex delivery systems for polyphenols amongst other bio-actives. To stabilize the oil–water interphase, dairy proteins are commonly employed, which are ideally replaced by other, more sustainable sources, such as insect proteins. In this study, lesser mealworm (Alphitobius diaperinus) protein concentrate (LMPC) is assessed and compared to whey protein (WPI) and pea protein (PPI), to stabilize W1/O/W2 emulsions and encapsulate a commercial polyphenol. The results show that LMPC is able to stabilize W1/O/W2 emulsions comparably to whey protein and pea protein when using a low-energy membrane emulsification system. The final droplet size (d4,3) is 7.4 µm and encapsulation efficiency is between 72 and 74%, regardless of the protein used. Under acidic conditions, the LMPC shows a similar performance to whey protein and outperforms pea protein. Under alkaline conditions, the three proteins perform similarly, while the LMPC-stabilized emulsions are less able to withstand osmotic pressure differences. The LMPC stabilized emulsions are also more prone to droplet coalescence after a freeze–thaw cycle than the WPI-stabilized ones, but they are the most stable when exposed to the highest temperatures tested (90 °C). The results show LMPC’s ability to stabilize multiple emulsions and encapsulate a polyphenol, which opens the door for application in foods. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of starch granules enriched with carvacrol and mixed with straw pellets (as poultry litter) on the mortality of larvae and adults of the lesser mealworm, Alphitobius diaperinus Panzer, a cosmopolitan pest inhabiting chicken houses in vast numbers worldwide. Additionally, the effect of starch granules on the growth parameters and survival of broiler chickens exposed to treated litter was examined. In this study, granules containing 3, 5, and 10% carvacrol was used. In a simulated chicken house bioassay, this material was mixed with pellets in three different proportions: 30/70%, 40/60%, and 50/50% (granules/pellets, respectively). On this medium, young larvae (approximately 10 days old), older larvae (last stage before pupa), and unsexed 7–10 days old adults of the lesser mealworm, with access to food, were colonized. Experiments were performed at 29°C in the dark. The study shows that poultry litter with the addition of starch granules enriched with 10% of carvacrol in the proportion of 40:60% (granules:pellets) appears to be the optimal medium applicable to broiler houses for A. diaperinus control. In this environment, all larvae and adults died within 3–4 days and the overall development of the experimental chickens was similar to that of the control. However, the feed conversion rate was slightly higher in the treated group (1.72) than in the control group (1.56). The average final body weight in the treated group was 100 g lower than that in the control group (the differences were not statistically significant).

ABSTRACT: This study analysed the effectiveness of using different levels of a product based on 6% cypermethrin and 2% citronella on broiler production and control the lesser mealworm (Alphitobius diaperinus). A total of 648 one-day-old chicks (Cobb®) which were allocated to one of three treatments (no application of the commercial product - control, and two concentrations of the product 2.00 and 3.33g/m2) in eight replicates with 27 birds each. The commercial product, which was based on cypermethrin was applied in the chambers with an atomizer. The lesser mealworm population was sampled weekly (1, 7, 14, 21, 28, 35 and 42 days of the experiment) using traps, at three points (front, middle and back) inside the pen. The performance, carcass and cut yields were evaluated. At 21, 28, 35 and 42 days of the experiment, the number of lesser mealworm adults and larvae was lower in the treatment groups involving 2.00 and 3.33g/m2 of the product than in the control group. On the first and 14th days of the study, the number of lesser mealworms adults was lower in the group treated with 3.33g/m2 of the product compared to the control group, although the results did not differ statistically from those obtained with 2.00g/m2 of the product. In conclusion, the application of the commercial product at both concentrations (2.00 and 3.33g/m2) was effective in combating Alphitobius diaperinus adults and larvae, and the performance was not influenced by treatments.

Insects are gaining attention as sustainable protein sources, necessitating the evaluation of gentle processing techniques for decontamination and fractionation of edible insects. Microfiltration was shown to be an effective alternative to thermal treatments for microbial decontamination of soluble insect protein. In this study, mealworm and cricket fractions extracted at pH 3 and 8, obtained through a microfiltration (0.2 μm polyethersulphone membrane) process, were assessed. This microfiltration process yielded a cream layer, a retentate containing protein aggregates, and a decontaminated permeate containing smaller-sized proteins (mostly <75 kDa). Microfiltration improved the permeates' foamability to values higher than whey protein isolate (215–317% vs. 163%), while the retentates retained the gelling properties of up to ≈5000 Pa. Additionally, stable lipid droplets resembling plant-based oleosomes were recovered from the cream layer. This study shows that microfiltration is promising for simultaneous decontamination and fractionation, providing distinct fractions for diverse food applications. [Display omitted] • Microfiltered permeates showed higher foaming capacities than pre-filtrates. • Protein hydrolysis by Alcalase was detrimental for the gelation behaviour. • Oleosome-like lipid droplets could be obtained from the top/cream layer. • Both permeates and retentates are affected by endogenous enzyme activity. • Enzymatic browning does not occur during fractionation at a pH value of 3. [ABSTRACT FROM AUTHOR]

Effective disinfection and disinsection are the keys to successful operation of modern poultry farms and the safety of poultry products. The cleaning and disinfection of poultry houses are important aspects of farm hygiene management. The correct execution of all steps of cleaning, disinfection, and disinsection procedures and the use of appropriate products are crucial for the prevention and control of zoonotic and animal diseases. In this study it was assumed that a water-based slow-release biocidal paint could be useful in controlling insect pests such as Alphitobius diaperinus and reducing microbiological contamination of air and litter in poultry houses and have a beneficial effect on microclimate in poultry houses. Therefore, the locations of A. diaperinus in the poultry houses, the microbiological contamination of air and litter, as well as the microclimatic conditions in the houses and the physicochemical parameters of the litter were evaluated. The results suggest that the tested biocidal paint could be an effective alternative to other insecticides and disinfectants. Additionally, the research is of a practical nature and may be very useful for poultry producers in controlling A. diaperinus populations and maintaining proper hygiene in poultry houses. Further research is needed.

The lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) is an important stored-product pest for the poultry industry as it is a vector of dangerous pathogens for humans. In the present study, we evaluated the short- and long-term mortalities of small and large larvae of A. diaperinus when they were exposed to concrete-covered Petri dishes treated with etofenprox, deltamethrin, and the combination of piperonyl butoxide+acetamiprid+d-tetramethrin. Small and large larvae were exposed to each insecticide applied on concrete surfaces with or without food. The short-term mortality was recorded after 1 day, 3 days, 5 days, and 7 days, while the long-term mortality was recorded 7 days after the transport of the larvae alive to pesticide-free concrete-covered dishes. Regarding short-term mortality levels, 97.8% and 80.0% of the small and large larvae, that were exposed to etofenprox without food, died after 7 days of exposure, respectively. Concerning deltamethrin, all tested small larvae were killed after 3 days (without food) and 5 days (with food) of exposure. For large larvae, deltamethrin caused 98.9% (with food) and 100.0% (without food) mortality levels after 5 days of exposure. The combination of piperonyl butoxide+acetamiprid+d-tetramethrin caused high mortality levels to small larvae, i.e., 84.4% and 100.0% on dishes with and without food, respectively, but low to moderate mortality levels to large larvae that did not exceed 67.8% after 7 days of exposure. Long-term mortality varied vastly among the tested insecticides. Etofenprox killed 100.0% of the small larvae on concrete without food, but 24.0% of the large larvae exposed to concrete containing food. Deltamethrin did not provide long-term mortality to large larvae when food was present. Piperonyl butoxide+acetamiprid+d-tetramethrin caused mortality rates that overall varied from 33.5% (large larvae on concrete with food) to 85.0% (small larvae on concrete with food). In conclusion, deltamethrin killed almost all exposed larvae at exposures of ≤5 days, regardless of their size and the presence of food on the concrete.

Water-in-oil-in-water (W1/O/W2) emulsions are complex delivery systems for polyphenols amongst other bio-actives. To stabilize the oil–water interphase, dairy proteins are commonly employed, which are ideally replaced by other, more sustainable sources, such as insect proteins. In this study, lesser mealworm (Alphitobius diaperinus) protein concentrate (LMPC) is assessed and compared to whey protein (WPI) and pea protein (PPI), to stabilize W1/O/W2 emulsions and encapsulate a commercial polyphenol. The results show that LMPC is able to stabilize W1/O/W2 emulsions comparably to whey protein and pea protein when using a low-energy membrane emulsification system. The final droplet size (d4,3) is 7.4 μm and encapsulation efficiency is between 72 and 74%, regardless of the protein used. Under acidic conditions, the LMPC shows a similar performance to whey protein and outperforms pea protein. Under alkaline conditions, the three proteins perform similarly, while the LMPC-stabilized emulsions are less able to withstand osmotic pressure differences. The LMPC stabilized emulsions are also more prone to droplet coalescence after a freeze–thaw cycle than the WPI-stabilized ones, but they are the most stable when exposed to the highest temperatures tested (90 °C). The results show LMPC’s ability to stabilize multiple emulsions and encapsulate a polyphenol, which opens the door for application in foods.

The objective of this experimental trial was to evaluate the efficacy of Spinosad against Alphitobius diaperinus developing in feces from laying hens of commercial eggs. The presence of adults and larvae of A. diaperinus, present in the manure located under the cages, on days -2 and -1, 1, 3, 6, 12, 19, 26, 33, 40, 47, 54 and 61 was evaluated after treatment. Spinosad, at a concentration of 250ppm, when applied at a dose of 0.126L / m² was shown to be ineffective against "lesser mealworm". The doses of 0.252L / m² and 0.504L / m² (400ppm) proved to be equally effective against adults of strawberries up to the 6th PDT, reaching efficacy percentages of 91.30% and 90.15%. Against A. diaperinus larvae, the dilutions of 0.126 L / m² and 0.252 L / m² (Spinosad - 400ppm) were effective, respectively, up to 19ºDPT (96.71%) and 33ºDPT (85.70%). The longest period of effectiveness against A. diaperinus was observed with Spinosad at 400ppm, at a dose of 0.504L / m²: 19DPT (89.55%) for adults and 54DPT (92.72%) for larvae, demonstrating the active period of this treatment, confirming the hypothesis that Spinosad has potential insecticide to control infestations of A. diaperinus infesting in commercial laying faeces, representing an alternative for poultry health programs that use the rotation of active ingredients as a way to mitigate the selection of resistance in populations of the coleoptera. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of starch granules enriched with carvacrol and mixed with straw pellets (as poultry litter) on the mortality of larvae and adults of the lesser mealworm, Alphitobius diaperinus Panzer, a cosmopolitan pest inhabiting chicken houses in vast numbers worldwide. Additionally, the effect of starch granules on the growth parameters and survival of broiler chickens exposed to treated litter was examined. In this study, granules containing 3, 5, and 10% carvacrol was used. In a simulated chicken house bioassay, this material was mixed with pellets in three different proportions: 30/70%, 40/60%, and 50/50% (granules/pellets, respectively). On this medium, young larvae (approximately 10 days old), older larvae (last stage before pupa), and unsexed 7-10 days old adults of the lesser mealworm, with access to food, were colonized. Experiments were performed at 29°c in the dark. The study shows that poultry litter with the addition of starch granules enriched with 10% of carvacrol in the proportion of 40:60% (granules:pellets) appears to be the optimal medium applicable to broiler houses for A. diaperinus control. In this environment, all larvae and adults died within 3-4 days and the overall development of the experimental chickens was similar to that of the control. However, the feed conversion rate was slightly higher in the treated group (1.72) than in the control group (1.56). The average final body weight in the treated group was 100 g lower than that in the control group (the differences were not statistically significant). [ABSTRACT FROM AUTHOR]

[Display omitted] • Lesser mealworm protein concentrate (LMPC) and polyphenols were conjugated by alkaline method. • Tannic acid exhibits higher binding affinity for LMPC than chlorogenic acid. • The conjugation with polyphenols enhanced the antioxidant activity of LMPC. • The oxidative stability of flaxseed oil emulsions improved when using conjugates. • The conjugates presented potential to be used as dual-functional ingredients. Lesser mealworm protein concentrate (LMPC) was conjugated with chlorogenic acid (CA) or tannic acid (TA) using an alkaline method. The impact of polyphenol type and concentration on the physicochemical and structural characteristics, antioxidant, interfacial, and emulsifying properties of the LMPC-polyphenol conjugates were investigated. Under the conditions tested, TA demonstrated higher affinity for LMPC compared to CA. The conjugation of LMPC induced conformational changes as showed by intrinsic fluorescence and FT-MIR raw spectra analysis. The surface hydrophobicity of the conjugates was reduced, leading to increased interfacial tension values for LMPC-TA conjugates without impairment of the emulsifying activity. The antioxidant properties were significantly improved by the conjugation. Flaxseed oil-in-water (O/W) emulsions stabilized by the conjugates and LMPC remained physically stable for 12 days at 50 °C with a notable reduction of secondary oxidation products when conjugates were used. LMPC-TA and LMPC-CA exhibited potential to be used as novel antioxidant emulsifiers in O/W emulsions. [ABSTRACT FROM AUTHOR]

Abstract This paper describes a methodology to evaluate Alphitobius diaperinus (Darkling beetle) population in order to estimate the effectiveness of control methods, consisting of direct sample collections from the poultry litter in 18 points, counting of adults and larvae, and subsequent comparison of the values obtained before and after of control strategies. It allows estimating the total population, population in a known area, as well to analyze the variations in different points all over the aviary. The method has shown to be very versatile, being indicated for population studies and efficacy evaluations, once it has already been validated in different experimental conditions.

Alphitobius diaperinus is an important pathogen with worldwide distribution that causes severe economic loss of efficiency in broilers. This study evaluates the potential of organic extracts of two strains entomopathogenic fungus Beauveria bassiana (CG71 and UNI40) as a biocontrol agent on A. diaperinus and promotes the phytochemical investigation. The effective percentages of mortalities were 95.97% (UNI40 methanolic extract), 69.23, 64.64, and 50.39% (CG 71 methanolic, ethyl acetate and butanol extracts). However, there was a decrease in the lesser mealworms susceptibility in relation to the use of insecticides and extracts. The metabolites 5-hydroxymethyl-2-furanoic acid, dipicolinic acid and monomethyl dipicolinate were isolated from ethyl acetate extract, and β-adenosine of butanolic extract of B. bassiana CG 71. In addition, the cyclodepsipeptides were identified in methanolic extracts of the two strains. The insecticide activity results indicated that the B. bassiana extracts are an alternative to A. diaperinus control. [ABSTRACT FROM AUTHOR]

Upon extracting soluble proteins from insects as potential food ingredient, endogenous enzymes, such as phenoloxidases, are expected to negatively affect protein properties. The effect of phenoloxidases on solubility and digestibility of proteins was investigated for larvae of Tenebrio molitor , Alphitobius diaperinus and Hermetia illucens. Phenoloxidase inhibition was done using blanching (50 s, 90 °C) before extraction or extracting in presence of sulfite. Similar soluble protein yields and compositions were found without and with sulfite addition, whereas blanching decreased soluble protein yield. Upon in-vitro hydrolysis by pepsin and trypsin, soluble proteins from H. illucens were more digestible than those of T. molitor and A. diaperinus. Phenoloxidase activity during grinding negatively affected in-vitro pepsin hydrolysis. Besides phenoloxidase activity, also endogenous proteases were shown to remain active at pH 8 in extracts containing sulfite and after blanching of larvae. This stresses that protease activity needs to be carefully controlled in the design of insect based ingredients. Unlabelled Image • Phenoloxidase during insect processing decrease in-vitro pepsin hydrolysis • Phenoloxidase did not influence soluble protein yields and composition from insects • Endogenous proteases in insects remain active in protein extracts after processing [ABSTRACT FROM AUTHOR]

Abstract This study focused on the coagulation behavior of protein from larvae of Alphitobius diaperinus. The effect of incremental CaCl 2 concentration (10, 15, 20 and 20 mmol/L) and temperature (90, 100 °C) on physical-chemical properties of insect coagula was investigated. A yield between 76 and 83 g of coagulum was obtained from 100 g of fresh larvae, decreasing with higher temperature and CaCl 2. Protein-protein interactions and microstructure of coagula were analyzed respectively by means of protein solubility, SDS-PAGE and SEM. When higher temperature was applied, hydrophobic interactions and disulphide bonds increased due to a larger degree of protein denaturation, thereby contributing to the formation of large protein aggregates. Thus, significant increase in hardness of the coagula was observed, with specimens at 20 mmol/L CaCl 2 being more than twice harder at 100 °C than at 90 °C. Moreover, proteins homologous to actin and tropomyosin contributed to the coagulum structure by hydrophobic interactions, whereas hemolymph proteins formed disulphide bonds. Increasing concentration of CaCl 2 from 10 to 20 mmol/L, at 100 °C, displayed a smoother network that increased coagula hardness from 1200 to 2900 g respectively. Results of this study provide important information for the product development in relation to insect protein-based meat analogues. Highlights • Lesser mealworm proteins coagulate into curds by calcium and high temperature. • Hydrophobic and sulphide interactions in insect proteins increase by temperature. • Texture of insect curds is dependent on microstructure and chemical interactions. [ABSTRACT FROM AUTHOR]

Reducing Alphitobius diaperinus in poultry production is a difficult task. However, attempts should be made to control the insect pest, as it poses a serious threat to the life and health of the chickens, as well as the workers on a farm. Our research was conducted in two stages to assess the effectiveness of the biocidal paint against A. diaperinus, containing active substances such as permethrin and a mixture of ultramarine and violet 23. In the first stage, under laboratory conditions, after 22 days, 100% mortality of A. diaperinus larvae and adults was achieved. This allowed us to assume that the biocidal paint may also be effective in poultry houses. In the poultry house where biocidal paint was applied, the number of insects decreased continuously alongside the sampling dates. In both research stages, the biocidal paint proved more effective against A. diaperinus than traditional limewash, and also the time to effective interaction of the paint was noted. Additionally, it was observed that the larvae were more susceptible to the active substances than adults. The research was practical, however, further analyses are necessary to fully control A. diaperinus, especially in poultry houses.

Insects are gaining interest as an alternative protein source for feed/food purposes. Although the lesser mealworm (LM) is commercially produced for human consumption, published data on its nutrient composition is scarce. This study reports on LM larvae reared on 18 different diets composed of side-streams to (1) determine the nutritional composition of the larvae and (2) study the effect of dietary changes on the larval nutrient composition. The LM larvae proved to be of good nutritional value with essential amino acids profiles comparable with that of beef and linoleic acid (C18:2) was the most dominant essential fatty acids in the larvae. The side-stream based diets varied on dry matter basis in protein (16−34%) and lipid content (2−19%). The nutrient content of the larvae reared on diets that supported good growth ranged between 37% and 49% of protein, 22% and 26% of lipid and 4% to 6% of chitin on dry matter basis. No significant correlations were identified between the larval protein or lipid content and that of the diet, but it was found between the diet nutrients and larval growth. Based on larval growth data and economic considerations, diets composed of wheat middlings with a 10−15% inclusion of rapeseed meal were identified as suitable feed for LM. Highest larval yields were obtained with diets containing 15−22% of proteins and 5−10% of lipids.

Insects are attracting increased attention in western countries as a protein source for feed and food industries. Currently, insect farmers use high-quality (cereal-based) diets. Part of the ingredients in these diets can also be used directly in food applications. To avoid competition and improve the sustainable and economical aspect of insect rearing, a search for alternative insect diets is ongoing. Side-streams from the agri-food sector offer potential. The lesser mealworm (Alphitobius diaperinus) is an insect that is commercially reared on large scale for food application. The current paper reports on six agri-food side-streams that were included in the diet of the lesser mealworm. The impact of 29 diets (single side-streams or mixtures) on the larvae growth was evaluated by monitoring the larval yield, efficiency of conversion of ingested feed, and larval weight. The larvae were able to grow on all diets, but differences in growth were observed. Two side-streams, wheat middlings and rapeseed meal, were proven to support good larval performance when used as a single ingredient. A combination of these two with brewery grains as moisture source provided (1) the best larval growth and (2) the most economically profitable diet. In conclusion, this study illustrates successful rearing of the lesser mealworm on side-stream-based diets.

The lesser mealworm, Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae), is considered the primary insect pest in broiler farms in Brazil. In this study, we characterized the susceptibility of A. diaperinus populations from broiler farms of southern Brazil to cypermethrin and chlorpyrifos. Larvae and adults of A. diaperinus were exposed to these technical insecticides diluted in acetone in residual bioassays. A geographic variation in the susceptibility of larvae and adults of A. diaperinus to both insecticides was detected. The larval LC50 for cypermethrin ranged from 0.43 to 7.33 μg a.i./cm2. Two populations from Santa Catarina state presented higher resistance ratios of 13.6- and 17-fold. When adults were exposed to cypermethrin, the LC ranged from 0.46 to 4.93 μg a.i./cm2, with population SC-3 from Santa Catarina having lower susceptibility (resistance ratio of 10.7-fold). When exposed to chlorpyrifos, A. diaperinus larvae present LC values ranging from 0.21 to 4.30 μg a.i./cm2. Larvae from Paraná and Santa Catarina (SC-1 population) presented the highest resistance ratios, ranging from 10- to 20-fold. In adults, the LC of chlorpyrifos ranged from 0.17 to 5.30 μg a.i./cm2, showing a maximum resistance ratio of 31-fold in a population from Paraná state. Based on LC99 values, candidate diagnostic concentrations of 15 and 12 μg a.i./cm2 of cypermethrin and chlorpyrifos, respectively, were also estimated for the resistance monitoring of A. diaperinus in Brazil. The implications of these results in Insect Resistance Management are discussed. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the potential accumulation of mycotoxins in the lesser mealworm (Alphitobius diaperinus, LMW) and black soldier fly (Hermetia illucens, BSF) larvae. Feed was spiked with aflatoxin B1, deoxynivalenol (DON), ochratoxin A or zearalenone, and as a mixture of mycotoxins, to concentrations of 1, 10, and 25 times the maximum limits set by the European Commission for complete feed. This maximum limit is 0.02 mg/kg for aflatoxin B1, 5 mg/kg for DON, 0.5 mg/kg for zearalenone and 0.1 mg/kg for ochratoxin A. The mycotoxins and some of their metabolites were analysed in the larvae and residual material using a validated and accredited LC-MS/MS-based method. Metabolites considered were aflatoxicol, aflatoxin P1, aflatoxin Q1, and aflatoxin M1, 3-acetyl-DON, 15-acetyl-DON and DON-3-glycoside, and α- and β-zearalenol. No differences were observed between larvae reared on mycotoxins individually or as a mixture with regards to both larvae development and mycotoxin accumulation/excretion. None of the mycotoxins accumulated in the larvae and were only detected in BSF larvae several orders of magnitude lower than the concentration in feed. Mass balance calculations showed that BSF and LMW larvae metabolized the four mycotoxins to different extents. Metabolites accounted for minimal amounts of the mass balance, except for zearalenone metabolites in the BSF treatments, which accounted for an average maximum of 86% of the overall mass balance. Both insect species showed to excrete or metabolize the four mycotoxins present in their feed. Hence, safe limits for these mycotoxins in substrates to be used for these two insect species possibly could be higher than for production animals. However, additional analytical and toxicological research to fully understand the safe limits of mycotoxins in insect feed, and thus the safety of the insects, is required. [ABSTRACT FROM AUTHOR]

Background: Even though insecticides are managed and the period of sanitary emptiness in poultry is respected, the elimination of Alphitobius diaperinus may not be successful. The use of essential oils of plant origin presents as a good alternative in the substitution of insecticides with synthetic molecules, since they are easy to obtain, with rapid degradation and without risk of residues for non-target organisms. The main objective of the present study was to examine whether Cinnamomum zeylanicum oil reduces Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) infestations under experimental conditions, without causing toxicity to broilers chicks exposed to treated litter. Materials, Methods & Results: The experimental design was completely randomized, with four replications per treatment. The treatments were as follows: solvent control using the diluent Dimethyl Sulfoxide 5% (oil diluent); chemical control using 5 g/m² cypermethrin; one spray of C. zeylanicum 5% oil; and two sprays of C. zeylanicum 5% oil. Each experimental unit was infested with 150 lesser mealworm adults. At 15 days of the broiler chick's life, blood was collected for biochemical analysis (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total protein, albumin, globulin, triglycerides and uric acid), and liver fragments were isolated for histopathological analysis. Using TupeTrap devices, we counted lesser mealworm 40 days after treatment. The treatments did not alter biochemical variables, and did not cause histopathological lesions in liver. The treatments with C. zeylanicum 5% oil with one and two sprays efficiently reduced lesser mealworm infestation compared with solvent control. Cypermethrin treatment had no effect. Discussion: Many of the commercial products present low effectiveness in the control of A. diaperinus, since the target organisms develop resistance to the product. In the present study, we used a higher cypermethrin dose than that recommended by the manufacturer, in order to increase efficacy in the face of possible resistance. Even so, cypermethrin did not efficiently control the organism. The effectiveness of the essential oil of C. zeylanicum tested can be attributed to the compounds found in greater quantity in the oil composition, such as cinnamaldehyde (41.27%), linalool (13.05%) and methyl eugenol (10.87%), characterized as responsible for the action of oil repellency. Monoterpenoid compounds found in essential oils extracted from plants have insecticidal action acting on the central nervous system of insects, which impairs their development, being characterized as neurotoxic compounds. The results found with the essential oil of C. zeylanicum are of great importance, since the control of A. diaperinus is not efficient because this organism has behavior that favors reinfestation in the poultry houses, such as shelter in cracks, in the draperies, below the feeders and in the soil. The biochemical analyzes of the blood can as important tools to assist in the monitoring of broilers health, in the diagnosis and treatment of diseases, and therefore the results presented are of great importance since they assist in the search for alternative methods for the control of A. diaperinus, where we can affirm that the essential oil of C. zeylanicum does not cause toxicity to broilers. Based on these results we can affirm that essential oil of Cinnamomum zeylanicum, 5%, is an effective substitute for existing commercially-available insecticides. [ABSTRACT FROM AUTHOR]

ABSTRACT: Diatomaceous earth (DE) is an inert powder obtained from milling the fossilized deposits of diatoms. Mainly composed of silica dioxide, DE is highly hygroscopic and is recommended for use in poultry houses as an evironmental conditioner, with a secondary action being the reduction of lesser mealworm populations Alphitobius diaperinus (Panzer). This study aimed to characterize and assess the insecticidal activity of a new environmental conditioner for poultry houses (Poultry Sec®, Vet Science Bio Solution, Maringá, Paraná, Brazil) in the laboratory. The study was conducted by adding DE to poultry feed (1, 2 and 3 g DE/kg feed), as well as by applying the DE to the poultry litter (86 and 172 g DE/m2), with A. diaperinus adults (26°C in the dark for 10 days). DE samples were analyzed by optical microscopy to measure and count the frustules and to identify the genera of the components. The insecticidal action of the product was observed. When applied to the litter, the DE caused between 83 and 85% mortality. With respect to the qualitative analysis of the diatoms, we estimated the concentration of 1.2 × 106 individuals/g of the product, distributed in nine distinct genera, with Brachysira Kützing being the predominant genus (40%).

The main aim of the presented paper is to assess the potential repellent effect of selected essential oils (EOs) against the lesser mealworm (Alphitobius diaperinus), which can cause economic losses in storage and in the poultry industry. Due to the development of pesticide resistance in A. diaperinus populations, as well as an attempt to limit extensive use of potentially harmful pesticides in food-related industries, there is a strong need for the development of alternative methods of dealing with A. diaperinus infestations. Because of their cost-effectiveness, availability and low vertebrate toxicity, EOs are promising agents in pest management. In the presented paper four off-the-shelf EOs: mint, vanilla, lemon and citronella (and mixtures of them) were tested as potential repellents. Moreover, a novel preference assay, providing an extended analysis of the preference and the locomotor response, was used. The most effective EOs were: citronella and lemon. EOs mixtures were generally more repellent than individual EOs, with the lemon and vanilla 1:1 mixture acting as the strongest repellent. A few of the tested EOs caused significant alterations to the locomotor activity, although no direct relation was observed. In conclusion, EOs can be potentially used as repellent agents in A. diaperinus management. Additionally, data on the locomotor activity may lead to designing better push-pull strategies in pest management.

O crescimento da produção avícola provocado pela alta demanda do mercado acarreta um aumento da criação de aves em confinamento, o que resulta em um aumento da densidade das aves dentro do galpão. Em função disso, há um incremento da umidade da cama aviária, proveniente tanto das excretas das aves, como da água dos bebedouros, que favorece o crescimento de populações do coleóptero Alphitobius diaperinus, popularmente conhecido como cascudinho. O contato direto do inseto com a cama das aves, assim como a alimentação a partir de aves moribundas e mortas, faz do A. diaperinus um veiculador de diversos patógenos, sendo destacados bactérias, protozoários e vírus que causam imunossupressão nas aves. Além da relação com os patógenos, os cascudinhos podem provocar danos nas instalações avícolas, pois, na fase larval, escavam túneis no material isolante para empuparem e destroem a proteção de poliuretano usada para isolamento térmico dos galpões em países de clima frio, a qual precisa ser trocada a cada dois ou três anos. Outro fator prejudicial às aves é a substituição da ração balanceada por larvas e adultos do coleóptero, uma vez que afeta o ganho de peso, principalmente, das mais jovens. Frente ao exposto, a presença do cascudinho em instalações avícolas torna-se um problema, tanto sanitário, como financeiro. O controle do A. diaperinus é considerado difícil, e inseticidas químicos são comumente utilizados em aviários, mas apresentam desvantagens, pois deixam resíduos na carcaça, bem como no meio ambiente. A presença de alta quantidade de matéria orgânica nos aviários provoca a diminuição da efetividade dos inseticidas químicos. Vários estudos vêm sendo desenvolvidos na busca de alternativas, como, por exemplo, nematoides e fungos entomapatogênicos, mas até o momento não são produzidos em escala comercial. Outra linha de pesquisa é a utilização de terra diatomácea, um pó-inerte que não deixa resíduos na carne de frango e no ambiente.The growth in poultry production because of the high market's demand causes an increase in the confinement raising, which increases the density of birds in poultry houses. As a result of this function, there is moisture increase in broiler litter, both from the excreta and drinkers, which favors the growth of the coleopterons Alphitobius diaperinus, popularly known as darkling beetle. The direct contact of the insects with the broiler litter as well as their feeding from dead and sick broilers make the A. diaperinus a vehicle for various pathogens, especially bacteria, protozoa and viruses. Besides the relationship with the pathogens, the darkling beetle can cause damage to poultry house, because at the larva stage they tent to burrow in to the insulating material and destroying the protection of polyurethane used for thermal insulation of poultry houses in countries with cold climate, which have to be changed every two or three years. Another harming factor to the broilers is the replacement of theirs balanced diet for larvae and adults of coleopterons, which affect the weight gain, mainly within younger individuals. Due to this factor, the presence of darkling beetle in poultry installations becomes a health as well as financial problem. The control of A. diaperinus is regarded as difficult and the use of chemical insecticides is common in poultry raising, even though it has disadvantages because it leaves residue in the carcass and in the environment. The presence of high amount of organic matter in poultry causes the decrease of the effectiveness of chemical insecticides. Several studies have been developed in research for alternatives, such as nematodes, fungi entomopathogenics, but they are not yet available commercially. Another line of research is the use of diatomaceous earth, an inert and non toxic powder which leaves no residues in chicken meat or in the environment.

This study aimed to investigate the potential accumulation of mycotoxins in the lesser mealworm (Alphitobius diaperinus, LMW) and black soldier fly (Hermetia illucens, BSF) larvae. Feed was spiked with aflatoxin B1, deoxynivalenol (DON), ochratoxin A or zearalenone, and as a mixture of mycotoxins, to concentrations of 1, 10, and 25 times the maximum limits set by the European Commission for complete feed. This maximum limit is 0.02 mg/kg for aflatoxin B1, 5 mg/kg for DON, 0.5 mg/kg for zearalenone and 0.1 mg/kg for ochratoxin A. The mycotoxins and some of their metabolites were analysed in the larvae and residual material using a validated and accredited LC-MS/MS-based method. Metabolites considered were aflatoxicol, aflatoxin P1, aflatoxin Q1, and aflatoxin M1, 3-acetyl-DON, 15-acetyl-DON and DON-3-glycoside, and α- and β-zearalenol. No differences were observed between larvae reared on mycotoxins individually or as a mixture with regards to both larvae development and mycotoxin accumulation/excretion. None of the mycotoxins accumulated in the larvae and were only detected in BSF larvae several orders of magnitude lower than the concentration in feed. Mass balance calculations showed that BSF and LMW larvae metabolized the four mycotoxins to different extents. Metabolites accounted for minimal amounts of the mass balance, except for zearalenone metabolites in the BSF treatments, which accounted for an average maximum of 86% of the overall mass balance. Both insect species showed to excrete or metabolize the four mycotoxins present in their feed. Hence, safe limits for these mycotoxins in substrates to be used for these two insect species possibly could be higher than for production animals. However, additional analytical and toxicological research to fully understand the safe limits of mycotoxins in insect feed, and thus the safety of the insects, is required.

O objetivo deste trabalho foi avaliar a interferência dos métodos de bioensaios nos resultados de seleção de fungos entomopatogênicos, com a utilização de quatro isolados de Beauveria bassiana e adultos de Alphitobius diaperinus. Quanto à forma de inoculação, foram testados os seguintes métodos: imersão do inseto em suspensão de conídios; pulverização da suspensão sobre insetos; e tratamento de superfície com a suspensão em oito concentrações. Para avaliar a interferência do tempo de imersão sobre a mortalidade, os insetos foram colocados em suspensão de conídios por 1, 10, 20, 30, 40, 50 e 60 segundos. Conídios produzidos em arroz, insetos e meio sintético foram utilizados para avaliar a influência do substrato na virulência dos isolados. Os isolados UNIOESTE 4 e CG 152 foram os mais virulentos pelos métodos imersão e pulverização, respectivamente; em tratamento de superfície, a mortalidade foi baixa para todos os isolados. Observou-se que a mortalidade dos insetos é proporcional ao tempo em que ficam imersos, com tendência a se estabilizar após 40 segundos. Os isolados CG 71 e CG 152, produzidos sobre insetos, foram menos virulentos. Os métodos utilizados podem influenciar os resultados de bioensaios de seleção de fungos para o controle de insetos.The objective of this work was to evaluate the interference of bioassay methods on the entomopathogenic fungi selection, using four Beauveria bassiana isolates and Alphitobius diaperinus adults. Regarding the inoculation form on insect mortality, the following methods were tested: insects immersion in a conidia suspension; spraying of a suspension over the insects; and surface treatment with eight concentrations. In order to evaluate the interference of immersion time on mortality, insects were immersed in a fungal suspension for 1, 10, 20, 30, 40, 50, and 60 seconds. Conidia produced on rice, insects, and synthetic medium were used to evaluate the influence of substrate on the virulence of the isolates. UNIOESTE 4 isolate and CG 152 were the most virulents for the methods immersion and spray, respectively; however, mortality was low in all isolates for the surface treatment. Mortality was proportional to the time during which insects stayed immersed, with a tendency to become stable after 40 seconds. Conidia from isolates CG 71 and CG 152 produced on insects were less virulent. The methods may influence bioassay results in the fungi selection for insects control.

Among all Tenebrionidae beetles Alphitobius diaperinus is considered a good choice for high-scale facility production of feed and food. It is widely considered that studies regarding the impact of the different dietary components on growth performances are very few and focused only on certain aspects, e.g. problems connected to the harmfulness of this species for stored products (rearing to test insecticides, studies about dietary preferences regarding different cereals). The real role of the different dietary components was never evaluated in order to better comprehend how to project diets that maximize productivity (maximum number of specimen as function of time). Research on the role of proteins and carbohydrates ascertained that a high protein content is required to obtain the best growth performances for this species. Carbohydrates also play a key role, though secondary to proteins. The diets thus obtained establish an important starting point for future formulations aimed at obtaining useful insects for feed and also for human consumption, soon to be legalized worldwide. [ABSTRACT FROM AUTHOR]

In the recent years, insect meals have been studied as alternative feed ingredients for aquafeeds, due to their adequate nutrient composition and low ecological footprint. These studies involve nutrient digestibility measurements, as they provide valuable information on the ability of fish to utilize insect meal efficiently. In this context, the current study evaluated the nutrient digestibility in European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) fed diets with five different insect meals. For this investigation, diets including 19.5 % of each insect meal from yellow mealworm (Tenebrio molitor – TM), black soldier fly (Hermetia illucens – HI), common housefly (Musca domestica – MD), super worm (Zophobas morio – ZM) or lesser mealworm (Alphitobius diaperinus – AD) and a control fish meal (FM) diet were tested. In European sea bass, TM and MD diets showed similar dry matter, protein, fat, energy, and organic matter ADCs among each other as well as with the FM diet (P > 0.05). However, adjusted protein ADC of TM and ZM diets (93.4 – 93.6 %) were significantly higher (P < 0.05) compared to the FM diet (91.9 %). Fat ADC was similar in all dietary groups (88.6–92.4 %; P > 0.05). The HI diet exhibited significantly lower dry matter, protein and organic matter ADCs compared to the FM diet (P < 0.05). Moreover, the AD diet presented significantly lower digestibility coefficients of dry matter, organic matter and energy than the FM diet (P < 0.05). The dietary contents of crude fiber and ash, and the inclusion of plant feedstuffs correlated negatively with various ADCs (P < 0.05). Regarding gilthead sea bream, the ADCs of dry matter, organic matter, protein, adjusted protein and energy were not affected by the different dietary treatments (P > 0.05). Fat ADC of the TM diet (73.6 %) was significantly lower compared to the other five diets (78.9–84.3 %; P < 0.05). The individual amino acid ADCs values were found to be very high in all experimental diets (90.9 – 98.0 % for European sea bass and 88.9 – 97.2 % for gilthead sea bream). In sea bass, the variation in crude protein and adjusted protein ADCs was strongly reflected on the individual amino acid ADCs. Nevertheless, the "true protein digestibility" as expressed by the sum of amino acids was not affected by the insect inclusion compared to the FM diet (P > 0.05), while a significant difference was observed between the ZM and HI diets (95.9 % and 94.1 % respectively; P < 0.05). In sea bream, the sum of amino acids and the individual amino acid ADC values did not differ among the experimental diets (P > 0.05) except for methionine (P < 0.05). Conclusively, in sea bream all diets exhibited similar overall digestibility. In sea bass, compared to the FM diet, TM and MD diets had similar or even slightly better digestibility, whilst diets HI and AD presented lower overall digestibility. • In sea bream overall digestibility was not affected by the different insect meals. • Diets with Tenebrio molitor or Musca domestica performed equally well in sea bass. • Hermetia illucens or Alphitobius diaperinus diets had lower digestibility. • Insect meal inclusion did not affect true protein digestibility. [ABSTRACT FROM AUTHOR]

This study aimed to identify and quantify the compounds present in the abdominal glands of Alphitobius diaperinus Panzer, 1797 (Coleoptera: Tenebrionidae) and to evaluate the influence of these compounds on its behavior. The extraction of volatiles present in the abdominal glands was made by dissection (10 individuals per sex) and by air entrainment (200 insects per sex), and they were analyzed by gas chromatography-flame ionization detector, gas chromatograph-mass spectrometer, and gas chromatograph- electroantennography detector (GC-EAD). The influence of these volatiles on the behavior of conspecifics was evaluated in a four-arm olfactometer. Twenty-three compounds were identified from male and female abdominal gland extracts, of which six were quinones: the 2-methyl-1,4-benzoquinone and the 2-ethyl-1,4-benzoquinone were the major components, and 1,4 benzoquinone and three hydroquinones were registered for the first time for this species. The GC-EAD analysis using the crude extracts from abdominal glands showed that male and female antennae responded to the three major benzoquinones. For the olfactometer bioassays, both genders were repelled either by the abdominal gland extracts or by synthetic solutions containing the three benzoquinones. The results suggest that the 1,4-benzoquinones play a role as a repellent to A. diaperinus. [ABSTRACT FROM AUTHOR]

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