Search Results (40)

The utilization of insects as a source of essential nutrients holds considerable promise, with the potential to serve as both feed and food. Consequently, there is a necessity to develop control systems, as the undeclared addition of insects to food products and/or non-compliance with labelling regulations may pose health risks and result in financial losses for consumers. This review describes methods for identifying and detecting insect species by targeting biomolecules such as DNA, proteins, saccharides, and metabolites, with a particular focus on DNA-based approaches. This review provides a detailed overview of the application of polymerase chain reaction (PCR) and DNA sequencing methods that are suitable for the analysis of edible and forage insects. The main focus is on identifying species that are approved for use as novel foods or insect feeds within the European Union (e.g., house cricket (Acheta domesticus), common mealworm (Tenebrio molitor), migratory locust (Locusta migratoria), lesser mealworm (Alphitobius diaperinus), black soldier fly (Hermetia illucens), banded cricket (Gryllodes sigillatus), field cricket (Gryllus assimilis), silkworm (Bombyx mori)). However, insect species of global relevance are also discussed. The suitability of DNA analysis methods for accurate species identification, detection of (un)labeled contaminants, and monitoring of genetic diversity has been demonstrated. Full article

The scientific interest in edible insects as an alternative source of high-value protein for the human diet has increased drastically over the last decade. Edible insects harbour enormous potential in terms of planetary health. Their lower water and land use, lower feed conversion ratios, and overall lower global warming potential paired with a high nutritional value compared with conventional livestock are key drivers towards an environmentally sustainable diet. However, low consumer acceptance, as well as regulatory challenges, have slowed down the success of edible insects in Western countries, despite edible insects being consumed regularly all over the world. To date, four edible insect species have been approved as novel foods in the European Union—namely yellow mealworm (Tenebrio molitor), migratory locust (Locusta migratoria), house cricket (Acheta domesticus), and lesser mealworm (Alphitobius diaperinus). Depending on the species, they have a high protein content (48–67%), with a beneficial indispensable amino acid profile, high fat content (21–39%), with a high content of unsaturated fatty acids based on the dry matter, and contain reasonable amounts of minerals and vitamins. Unlike other animal-based foods, edible insects contain dietary fibre. Data on the bioavailability of nutrients in humans are scarce. Although numerous publications have investigated the nutritional profiles, environmental impacts, and future perspectives of edible insects, here, those findings are reviewed critically, as some publications were partially contradictory or related to selected species only. In this narrative review, we emphasise that edible insects could play a key role in a changing world with a steadily increasing demand for nutritionally valuable food and the depletion of natural resources. Full article

Insect-based dog food is increasingly becoming available in pet food markets, potentially offering environmental and nutritional benefits, depending on insect species and how they are reared, processed, and utilized. However, there is limited understanding of dog owners’ attitudes towards the use of insects as protein alternatives for dogs. An online survey was conducted to explore Australian dog owners’ (n = 201) attitudes towards insect-based pet food, segmenting participants according to their food neophobia, previous insect consumption, and dog-human relationship. Participants’ dog food purchases were highly influenced by perceived health/nutrition, palatability, and product quality, with these factors being of most importance to ‘dog people’ (i.e., participants with closer relationships with their dogs). Participants were reasonably accepting of insect-based pet food made from mealworms and crickets and slightly accepting of products made from black soldier fly larvae. In contrast, participants’ responses to plant-based pet foods were neutral. Food neophiles, and to a lesser extent, insect-eating consumers (i.e., those who had previously eaten insects), were found to be more willing to feed their dogs insects in comparison to non-neophiles and non-insect-eating consumers. Overall, Australian dog owners appear to be supportive of feeding their dogs diets supplemented with insect protein. Insights from this study will help inform the development and marketing of insect-based pet foods. Full article

The lesser mealworm (Alphitobius diaperinus) is a significant pest in poultry facilities, transmitting pathogens such as Salmonella and causing structural damage in poultry operations. Challenges such as insecticide resistance and environmental concerns associated with the widespread use of traditional insecticides underscore the need for sustainable alternatives. This review examines biological and sustainable management strategies for managing the lesser mealworm, including entomopathogenic fungi, bacteria, nematodes, plant essential oils-extracts, pheromones, and diatomaceous earth. These eco-friendly approaches highlight fungi and nematodes for their effectiveness in larval control and essential oils for their insecticidal and repellent properties. The application of pheromones and diatomaceous earth further complements other methods within integrated pest management (IPM) systems. Integrating these biological tools into IPM offers a sustainable and effective solution for reducing A. diaperinus populations, addressing both health and environmental concerns. Full article

The lesser mealworm, Alphitobius diaperinus, is a widespread pest in poultry farming, causing economic losses and facilitating the spread of pathogens. Current control methods rely heavily on synthetic insecticides, which raise environmental concerns and contribute to resistance. This study investigated the insecticidal potential of Moringa oleifera seed preparations, including an aqueous extract (AE), a protein-enriched fraction (PF), and an isolated lectin (WSMoL), against A. diaperinus. Contact assays demonstrated that AE and PF reduced adult survival by up to 90% and 100%, respectively, while WSMoL was effective only against larvae, causing 48% mortality. Ingestion assays showed that AE and PF reduced adult survival by 60% and 30%, respectively; impaired diet utilization; and caused significant weight loss. WSMoL exhibited antinutritional effects, including a 94% reduction in trypsin-like activity, but did not cause lethality, although it may impair long-term survival. Midgut histological analysis revealed epithelial disorganization, vacuolization, and nuclear condensation in the treated insects. These findings suggest that M. oleifera seed preparations are promising candidates for sustainable pest control, offering both lethal and sublethal effects on A. diaperinus. Future research should focus on the development of formulations and long-term impact assessments on pest populations and non-target organisms, paving the way for eco-friendly alternatives in integrated pest management. Full article

In the veterinary field, particularly in the poultry farming sector, Alphitobius diaperinus (Panzer, 1797) (Coleoptera: Tenebrionidae) is a significant pest that causes economic losses and acts as a vector for various pathogens. This study is the first to evaluate the efficacy of the entomopathogenic nematode Steinernema feltiae Filipjev, 1934 against both the larval (fifth instar) and imago (adult) of A. diaperinus from various Turkish populations. The insects were collected from six poultry farms in the provinces of Balikesir, Bolu, Canakkale, Manisa, and Izmir in Türkiye, bred, and then tested at concentrations ranging from 25 to 200 infective juveniles (IJs) per milliliter. Mortality was monitored over a five-day period. The findings revealed that larvae were much more susceptible to S. feltiae nematodes compared to adults, with LC₅₀ values of larvae ranging from 33.17 to 83.12 IJs/mL. The Manisa population was the most susceptible, while the Izmir population was the most resistant. These results suggest that S. feltiae could be an effective biological control agent for managing A. diaperinus in Turkish poultry farms, reducing the reliance on chemical insecticides. Full article

In the present work, chemical and enzymatic assisted techniques were compared for protein extraction from lesser mealworm larvae (LM, Alphitobius diaperinus), recently approved as a novel food in the European Union. All extracts showed appreciable nutritional quality, with quantities of essential amino acids above the reference standard. Conventional alkali extraction allowed the isolation of only 73% of the protein, preserving the amino acid composition but potentially causing denaturation or racemisation. The “stepwise” method, following the Osborne fractionation, improved protein recovery to 91% by isolating four fractions with different solubility properties. Additionally, enzymatic hydrolysis using Bacillus licheniformis proteases was also tested, and it provided hydrolysates with an average degree of hydrolysis of 14%, making them a potential hypoallergenic solution. Overall, these findings indicate the ability to tailor the composition of LM protein to meet specific needs, offering promising prospects for the use of insect protein ingredients in various applications. Full article

Waste from non-degradable packaging materials poses a serious environmental risk and has led to interest in developing sustainable bio-based packaging materials. Sustainable packaging materials have been made from diverse naturally derived materials such as bamboo, sugarcane, and corn starch. In this study, we made a sustainable packaging film using chitosan extracted from the biomass of yellow mealworm (Tenebrio molitor) shell waste. The extracted chitosan was used to create films, cross-linked with citric acid (CA) and with the addition of glycerol to impart flexibility, using the solvent casting method. The successful cross-linking was evaluated using Fourier-Transform Infrared (FTIR) analysis. The CA cross-linked mealworm chitosan (CAMC) films exhibited improved water resistance with moisture content reduced from 19.9 to 14.5%. Improved barrier properties were also noted, with a 28.7% and 10.2% decrease in vapor permeability and vapor transmission rate, respectively. Bananas were selected for food preservation, and significant changes were observed over a duration of 10 days. Compared to the control sample, bananas packaged in CAMC pouches exhibited a lesser loss in weight because of excellent barrier properties against water vapor. Moreover, the quality and texture of bananas packaged in CAMC pouch remained intact over the duration of the experiment. This indicates that adding citric acid and glycerol to the chitosan structure holds promise for effective food wrapping and contributes to the enhancement of banana shelf life. Through this study, we concluded that chitosan film derived from mealworm biomass has potential as a valuable resource for sustainable packaging solutions, promoting the adoption of environmentally friendly practices in the food industry. Full article

The highly prevalent pest Alphitobius diaperinus (Coleoptera: Tenebrionidae) causes significant structural damage in poultry farms. Despite previous investigations on its carriage of pathogenic microorganisms, our understanding of its microbiome remains limited. This study aimed to analyze the diversity of culturable gut microbiota in A. diaperinus obtained from laboratory breeding. Fifteen seventh instar larvae underwent a 24-h starvation period, followed by surface disinfection. Dissected midguts were homogenized and plated on nutrient agar (NA), brain heart infusion agar (BHI), and Bacillus cereus agar (BC). The cultured isolates were subjected to gram staining, phylogenetic analysis, biochemical property evaluation, and metabolic activity assessment. Bacterial counts were higher in BHI (2.51 × 10⁵ CFU/gut) than in NA (2.25 × 10⁵ CFU/gut), possibly due to nutrient richness. NA exhibited a dominant colony morphology of gram-negative bacilli, while BHI displayed additional distinct colonies of gram-positive cocci. Surprisingly, yeast-like colonies were observed on BC plates. Based on 16S rRNA gene sequences, eight bacterial isolates were identified as Enterobacter sp., and two as Staphylococcus sp. Using RNA gene ITS region sequences, two yeast isolates were identified as Debaryomyces sp. and Hyphopichia sp. A preliminary species-level identification of bacteria (Enterobacter cloacae, Staphylococcus gallinarum, and Staphylococcus succinus) was achieved using API systems and complementary biochemical tests. Discrepancies between phylogenetic analysis and phenotypic data suggest the potential existence of new species or subspecies. Further comprehensive studies are required to confirm this hypothesis. Full article

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. Full article

In this study, we evaluated the susceptibility of Alphitobius diaperinus larvae and adults to saline extract (SE), lectin-rich fraction (FR), and isolated lectin (MvRL) from Microgramma vacciniifolia rhizomes. To determine immediate effects, larvae and adults were exposed to SE (10.5 mg/mL), FR (7.5 mg/mL), or MvRL (1.0 mg/mL) for 48 h. Live insects were evaluated for acetylcholinesterase (AChE) activity. The delayed effects of SE (10.5 mg/mL), FR (7.5 mg/mL), and MvRL (0.2 and 0.4 mg/mL) were checked by incubating the adults for 16 days with a diet containing the preparations. In vitro effects on gut digestive enzymes were investigated. All preparations showed immediate larvicidal effect but had no effect on adult survival. Extracts from FR-treated larvae showed higher AChE activity than control insects. In the delayed effect assay, the adults lost biomass after consuming SE and FR. FR was the most effective inhibitory agent of trypsin-like and amylase activities (88% and 65% inhibition, respectively). All preparations inhibited endoglucanase activity in 94–98%, while SE and FR inhibited exoglucanase activity in 93.2 and 94.1%, respectively. In conclusion, M. vacciniifolia rhizomes contain compounds (including MvRL) that affect the survival and physiology of A. diaperinus, acting as potential natural insecticides for controlling this pest. Full article

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. Full article

Several studies have shown that mealworms (Tenebrio molitor L.) could provide animals and humans with valuable nutrients. Tenebrio molitor larvae were studied to determine whether their rearing diets affected their fat and fatty acid content and to ascertain if it is possible to detect the changes in the larval fat composition using near-infrared reflectance spectroscopy (NIRS). For this reason, a standard control diet (100% wheat bran) and an experimental diet, consisting of wheat bran and the supplementation of a different substrate (coconut flour, flaxseed flour, pea protein flour, rose hip hulls, grape pomace, or hemp protein flour) were used. The results showed lesser weight gain and slower growth rates for larvae raised on diets with a high fat content. A total of eight fatty acids were identified and quantified, where palmitic, oleic, and linoleic acids were the most prevalent and showed a correlation between larval content and their content in the rearing diets. There was a high content of lauric acid (3.2–4.6%), myristic acid (11.4–12.9%), and α-linolenic acid 8.4–13.0%) in mealworm larvae as a result of the high dietary content of these fatty acids. NIR spectra were also influenced by the fat and fatty acid composition, as larval absorbance values differed greatly. The coefficient of the determination of prediction (R²_P) was over 0.97, with an RPD value of 8.3 for the fat content, which indicates the high predictive accuracy of the NIR model. Furthermore, it was possible to develop calibration models with great predictive efficiency (R²_P = 0.81–0.95, RPD = 2.6–5.6) for all fatty acids, except palmitoleic and stearic acids which had a low predictive power (R²_P < 0.5, RPD < 2.0). The detection of fat and fatty acids using NIRS can help insect producers to quickly and easily analyze the nutritional composition of mealworm larvae during the rearing process. Full article

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. Full article

The ultrasound-assisted extraction (UAE) of oil from lesser mealworm (Alphitobius diaperinus L.) larvae powders (LMLPs) using ethanol/isopropanol as the superior solvent was optimized. The evaluation of time (9.89–35.11 min), solvent-to-LMLPs (2.39–27.61 v/w), and temperature (16.36–83.64 °C) showed that the highest extraction efficiency (EE, 88.08%) and in vitro antioxidant activity (IVAA) of reducing power (0.651), and DPPH free-radical scavenging capacity (70.79%) were achieved at 22.5 v/w solvent-to-LMLPs and 70 °C for 22.64 min. Optimal ultrasound conditions significantly improved the EE than n-hexane extraction (60.09%) by reducing the electric energy consumption by ~18.5 times from 0.637 to 0.035 kWh/g. The oil diffusivity in ethanol-isopropanol during the UAE (0.97 × 10⁻⁹ m²/s) was much better than that of n-hexane (5.07 × 10⁻¹¹ m²/s). The microstructural images confirmed the high efficiency of ethanol-isopropanol in the presence of ultrasounds to remove oil flakes from the internal and external surfaces of LMLPs. The improved IVAA was significantly associated with the total phenolic (4.306 mg GAE/g, r = 0.991) and carotenoid (0.778 mg/g, r = 0.937) contents (p < 0.01). Although there was no significant difference in the fatty acid profile between the two extracted oils, ethanol-isopropanol under sonication acceptably improved oxidative stability with lower peroxides, conjugated dienes and trienes, and free fatty acids. Full article