Lesser Mealworm Research Articles

Lesser mealworm (Alphitobius diaperinus) protein concentrate conjugated with tannic acid improves the oxidative stability of W1/O/W2 emulsions loaded with beet by-product extract and linseed oil

For improving the oxidative stability of a polyunsaturated oil, we co-encapsulated polyphenols from a concentrated beet by-product extract (CEB) with linseed oil using W1/O/W2 emulsions produced through emulsification with dynamic membranes of tunable pore size (DMTS), a low-energy high-throughput emulsification technology. Emulsions were stabilized with lesser mealworm protein concentrate (LMPC) and with an LMPC-derived antioxidant emulsifier (LMPC conjugated to tannic acid (LMPC-TA)). Regarding productivity, values of transmembrane flux were high (above 100 m3 m−2 h−1), and of industrial interest. Regardless of the protein used, emulsions showed an encapsulation efficiency higher than 67.5 %, while droplet size (D4,3) was below 8.28 μm. All emulsions were physically stable for 16 days at 4 °C, while at 25 °C, those stabilized with LMPC-TA had a less pronounced increase in D4,3. In all cases, emulsions containing CEB and LMPC-TA inhibited oil oxidation, increasing the shelf life of the emulsions.

Biotransformation of insect processing residues: Production of lactic acid bacterial biomass and associated partial removal of proteins from chitin

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 log10 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.

Mitogenomic profiling and gut microbial analysis of the newly identified polystyrene-consuming lesser mealworm in Kenya

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.

Eryngo essential oil nanoemulsion stabilized by sonicated-insect protein isolate: An innovative edible coating for strawberry quality and shelf-life extension

New bioactive coatings with eryngo essential oil (EEO) nanoemulsions stabilized by ultrasonically-treated lesser mealworm protein isolate (LMPI) were developed to extend strawberry shelf life and quality. EEO due to high carvone (43.03 %), phenolics (87.45 mg gallic acid equivalent/g), flavonoids (13.56 mg quercetin equivalent/g), and carotenoids (635.07 mg/kg) contents exhibited a significant antioxidant activity comparable to ascorbic acid (AA) and BHT. Nanoemulsions stabilized with 9 % sonicated LMPI showed smaller droplet size, higher negative ζ-potential, and greater stability, turbidity, and encapsulation efficiency of EEO compared to those stabilized with native LMPI. The FTIR spectra showed that sonicated LMPI had structural changes enhancing its emulsifying activity, with key peaks indicating the presence of hydrogen bonds, carbonyl groups, and protein conformations in both EEO and LMPI. Strawberries coated with optimal EEO-loaded nanoemulsions showed superior quality with minimal storage-dependent physicochemical, textural, color, and sensory changes compared to control samples. This edible coating also maintained higher total monomeric anthocyanin and AA contents with lower peroxidase activity during storage than EEO-based coatings. However, no significant difference in superoxide dismutase activity between samples covered by EEO and EEO-loaded nanoemulsions over 14 days of storage was found. Bioactive nanoemulsions stabilized by insect proteins would be an eco-friendly and safe approach to upholding quality standards in stored fruits and vegetables.

Unravelling the Influence of Extraction Techniques on Protein Yield and Nutritional Value in Lesser Mealworm Larvae.

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.

Volatile compounds and quality changes of lesser mealworm larvae: effect of blanching, storage temperature and time

Abstract The impact of blanching and storage temperature (−20 °C and −80 °C) on the formation of volatile organic compounds and changes in quality characteristics of lesser mealworm (Alphitobius diaperinus) larvae was examined over seven weeks. Acid and peroxide values, pH, and colour of lesser mealworm larvae were significantly affected by the studied variables. The changes in these characteristics as well as in the volatile profile indicated occurring lipid oxidation and lipid hydrolysis processes during the storage. The intensity of these reactions was mostly influenced by blanching treatment and storage time, and a lesser extent by storage temperature. It was proposed that changes in composition and intensity of volatiles can be used for rapid quality assessment of lesser mealworm larvae during frozen storage. Thus, the selection of optimum storage conditions for lesser mealworm larvae is important for the prevention of undesirable chemical reactions and preservation of the quality of insect biomass.

Replacing soybean meal with lesser mealworm Alphitobius diaperinus improves broiler productive performances, haematology, intestinal morphology and meat quality

Abstract Insects are becoming more popular as a soybean meal substitute because they can be raised sustainably on food and feed residues, which improves farming efficiency, sustainability, and animal welfare. In the current study, we replaced 4, 8 and 12% SBM with lesser mealworm Alphitobius diaperinus (Coleoptera: Tenebrionidae) larvae and determined its effects on productive performances, blood parameters, gut morphometry and meat quality of the broiler chickens. We also compared commercially available black soldier fly Hermetia illucens (Diptera: Stratiomyidae) larvae. A total of 350 one-day-old broiler chicks (Ross 308) were randomly assigned to seven isocaloric and isonitrogenous diets (5 pens/treatment and 10 birds/pen). The results found that 12% A. diaperinus and H. illucens diets significantly () increased the live weight (LW) and average daily weight gain (ADG) while improving feed conversion ratio (FCR) in the broilers. Daily feed intake (DFI) did not show a significant difference () among all the dietary treatments. Haematology and serum biochemistry traits were significantly () improved except MCHC, monocytes, Eosinophils (EO), albumin and creatinine. The 12% A. diaperinus and H. illucens diets showed the highest villus height (Vh) and the lowest crypt depth than other diets. The meat quality traits were statistically () improved except meat pH, drip loss and shear force (). The results of the study highlight the importance of substituting SBM up to 12% with either A. diaperinus or H. illucens larvae, which improves the productive performances, blood parameters, gut morphometry and meat quality of broilers and thus can be incorporated as an alternative protein source in poultry feed.

The adaptive prowess of the lesser mealworm Alphitobius diaperinus (Coleoptera: Tenebrionidae): Insights from mouthpart morphology and mitogenomic analysis

The lesser mealworm, Alphitobius diaperinus (Panzer, 1797), is a pervasive pest known to infest stored products and poultry facilities worldwide, posing significant challenges for pest management. Understanding its adaptability to diverse environments is crucial for devising effective control strategies. This study investigated adult mouthparts and analyzed the mitogenome of A. diaperinus using specimens obtained from a cat litter box. The examination of mouthparts revealed notable intraspecific variations, suggesting potential adaptations to different ecological conditions. Analysis of the mitogenomes unveiled nucleotide variations in protein-coding genes (PCGs), ribosomal RNA genes (rRNAs), and the control region, with all mutations in PCGs being nonsynonymous, primarily occurring at the second codon positions. Evaluation of Ka/Ks ratios indicated purifying selection acting on the PCGs of A. diaperinus. Phylogenetic analyses consistently placed the newly sequenced sample within the same clade as previously sequenced A. diaperinus samples. The presence of A. diaperinus in cat litter highlights its remarkable adaptability to diverse habitats. Furthermore, intraspecific variation in mouthpart morphology and the mitogenome suggests ongoing adaptations to various food sources and environmental niches. These findings underscore the dynamic nature of A. diaperinus adaptations and emphasize the importance of continued research for effective pest management strategies.

Mentha spp. essential oils: toxicity to Alphitobius diaperinus, activity against poultry pathogenic bacteria, and Beauveria bassiana compatibility.

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.

Strong resistance to β-cyfluthrin in a strain of the beetle Alphitobius diaperinus: a de novo transcriptome analysis.

The lesser mealworm, Alphitobius diaperinus, is an invasive tenebrionid beetle and a vector of pathogens. Due to the emergence of insecticide resistance and consequent outbreaks that generate significant phytosanitary and energy costs for poultry farmers, it has become a major insect pest worldwide. To better understand the molecular mechanisms behind this resistance, we studied a strain of A. diaperinus from a poultry house in Brittany that was found to be highly resistant to the β-cyfluthrin. The strain survived β-cyfluthrin exposures corresponding to more than 100 times the recommended dose. We used a comparative de novo RNA-Seq approach to explore genes expression in resistant versus sensitive strains. Our de novo transcriptomic analyses showed that responses to β-cyfluthrin likely involved a whole set of resistance mechanisms. Genes related to detoxification, metabolic resistance, cuticular hydrocarbon biosynthesis and proteolysis were found to be constitutively overexpressed in the resistant compared to the sensitive strain. Follow-up enzymatic assays confirmed that the resistant strain exhibited high basal activities for detoxification enzymes such as cytochrome P450 monooxygenase and glutathione-S-transferase. The in-depth analysis of differentially expressed genes suggests the involvement of complex regulation of signaling pathways. Detailed knowledge of these resistance mechanisms is essential for the establishment of effective pest control.

Integrated ultrasonic-transglutaminase modification of lesser mealworm protein isolate: A pioneering cobalamin delivery vehicle in gluten-free breads

A combined approach of microbial transglutaminase (MTGase) crosslinking and high-intensity ultrasound (HIU) was implemented to improve the physicochemical, rheological, structural, and thermal properties, as well as the targeted release of vitamin B12 of lesser mealworm protein isolate (LMPI)-based gels. Prolonging HIU to 60 min significantly reduced LMPIs' size, polydispersity, zeta-potential, and fluorescence intensity while increasing surface hydrophobicity, free amino (FAGs), and sulfhydryl (FSGs) groups. The MTGase-catalyzed LMPI gels effectively decreased the content of FAGs and FSGs. LMPI gels from 60 and 75 min HIU and MTGase catalysis exhibited a shear-thinning flow behavior, superior thermal stability, and improved water retention and gel strength with the most controlled release of vitamin B12 during in vitro simulated gastrointestinal digestion. Incorporating freeze-dried gel powders from 60 min HIU-treated MTGase-catalyzed LMPI and pea protein isolate into the dough of a new gluten-free bread improved physicochemical, textural, and sensory properties, with notable vitamin B12 retention rate.

Alphitobius diaperinus larvae (lesser mealworm) as human food – An approval of the European Commission – A critical review

Abstract Due to the increasing threat of climate change and the need for sustainable food sources, human consumption of edible insects or entomophagy has gained considerable attention globally. The larvae of Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae), also known as the lesser mealworm, have been identified as a promising candidate for mass-rearing as a food source based the on evaluation on several aspects such as the production process, the microbiological and chemical composition, and the potential allergenicity to humans. As a consequence, the European Commission has recently approved the utilization of lesser mealworms as human foods. Lesser mealworms are considered a good source of protein, with a protein content ranging from 50-65% of their dry weight and containing various essential amino acids. Lesser mealworms are also rich in other essential nutrients such as iron, calcium, and vitamins B12 and B6. Furthermore, the hydrolysates of lesser mealworms are known to contain antioxidants, suggesting the therapeutic properties of the insects. To enable and ensure a continuous supply of lesser mealworms, various rearing procedures of the insects and information on optimal environmental rearing conditions have been reported. However, like other edible insects, lesser mealworms are still not commonly consumed in Western countries because of various consumer- and product-related factors. Ultimately, the European Commission’s approval of lesser mealworms as a novel food is a key milestone in the development of the insect food industry. Embracing the consumption of edible insects can help address the challenges of feeding a growing population, mitigate the environmental impact of food production, and promote a more sustainable and resilient food system for the future.

Effects of dietary exposure to plant toxins on bioaccumulation, survival, and growth of black soldier fly (Hermetia illucens) larvae and lesser mealworm (Alphitobius diaperinus)

In their natural habitat, insects may bioaccumulate toxins from plants for defence against predators. When insects are accidently raised on feed that is contaminated with toxins from co-harvested herbs, this may pose a health risk when used for human or animal consumption. Plant toxins of particular relevance are the pyrrolizidine alkaloids (PAs), which are genotoxic carcinogens produced by a wide variety of plant species and the tropane alkaloids (TAs) which are produced by a number of Solanaceae species. This study aimed to investigate the transfer of these plant toxins from substrates to black soldier fly larvae (BSFL) and lesser mealworm (LMW). PAs and the TAs atropine and scopolamine were added to insect substrate simulating the presence of different PA- or TA-containing herbs, and BSFL and LMW were grown on these substrates. Bioaccumulation from substrate to insects varied widely among the different plant toxins. Highest bioaccumulation was observed for the PAs europine, rinderine and echinatine. For most PAs and for atropine and scopolamine, bioaccumulation was very low. In the substrate, PA N-oxides were quickly converted to the corresponding tertiary amines. More research is needed to verify the findings of this study at larger scale, and to determine the potential role of the insect and/or substrate microbiome in metabolizing these toxins.

Effects of Fishmeal Substitution with Mealworm Meals (Tenebrio molitor and Alphitobius diaperinus) on the Growth, Physiobiochemical Response, Digesta Microbiome, and Immune Genes Expression of Atlantic Salmon (Salmo salar).

A 12-week growth trial was conducted to assess the effects of mealworm meals, as a substitution for fishmeal, on the growth, physiobiochemical responses, digesta microbiome, and immune-related genes expression of Atlantic salmon (Salmo salar). Twenty Atlantic salmon parr (38.5 ± 0.1 g, initial weight) were stocked into each of 16 tanks in a recirculating aquaculture system. A fishmeal-based diet (100% FM) was used as the control treatment and was compared with three test diets where: (1) fishmeal was partially (50%) replaced with defatted mealworm meal, Tenebrio molitor (50% DMM), (2) fishmeal was fully replaced with defatted mealworm meal (100% DMM), and (3) fishmeal was partially replaced with whole lesser mealworm meal, Alphitobius diaperinus (50% WMM). All substitutions were done on a crude protein basis. Each of the four experimental diets was evaluated in quadruplicate tanks as part of randomized design. The results indicated that Atlantic salmon showed high survival (greater or equal to 98.8%), and no significant difference in final growth, feed efficiency, feces stability and condition indices. Hepatosomatic index was lower in fish fed 100% DMM and 50% WMM when compared to fish fed the control diet (100% FM). Whole-body proximate and amino acid compositions were not statistically different between treatments, while essential fatty acids, including linolenic, eicosapentaenoic acid, and homo-a-linolenic, were lower in fish fed 100% DMM. Plasma parameters (total protein, alanine aminotransferase, alkaline phosphatase, and total iron-binding capacity), hepatic peroxide, and antioxidant enzymes were not significantly affected by dietary substitutions, whereas plasma immunoglobulin M showed significantly higher levels in fish fed 50% DMM and 100% DMM when compared to fish fed the control diet (100% FM). The inclusion of mealworm meals significantly impacted the overall microbiome composition but not the richness and evenness of the salmon digesta microbiomes compared to control. The most common genus in all treatments was Pseudomonas, which has been previously shown to have both commensal and pathogenic members. The relative expressions of growth (IGF-I) and protein synthesis (TIPRL) were not significantly different between the treatments, whereas immunoglobulin genes (IgM, IgD, and IgT) were significantly upregulated in fish fed the DMM diets when compared to fish fed the control diet. Overall, this study suggests that the mealworm meals tested could be suitable alternatives to fishmeal in the diet of Atlantic salmon.

Chemical composition, fatty acid profile, antioxidant content, and microbiological loads of lesser mealworm, mealworm, and superworm larvae

In the last decade, great attention was placed on insects to increase feed-food production without negatively affecting the environment. In this research study we compare three different insect species (Alphitobius diaperinus, Tenebrio molitor, and Zophobas morio - lesser mealworm, mealworm, and superworm), fed the same substrate, on the chemical composition, fatty acid (FA) profile, antioxidant content, and microbiological loads. Superworm larvae show higher dry matter (38.06%) and ether extract (17.65%) contents followed by mealworm and lesser mealworm larvae (32.77%, 27.11% and 13.86%, 10.78%, respectively). No differences were detected in the crude protein and ash content. Superworm larvae showed the highest content of SFA (41.43% vs 39.16% and 28.52% of total FA, in lesser mealworm and mealworm, respectively), while mealworm larvae were the richest in MUFA (40.61% vs 34.38% and 32.98% of total FA, in super and lesser mealworm, respectively) and PUFA (29.05% vs 22.29% and 21.21% of total FA in super and lesser mealworm, respectively). Anyhow, in all the larvae the three more representative fatty acids were oleic acid, linoleic acid, and palmitic acid. The least beneficial ratio of n-6/n-3 was detected in Alphitobius diaperinus larvae (53.84), while Zophobas morio larvae showed the healthier ratio (16.04). The antioxidant contents determination revealed a linkage to the fatty acids content. Low differences were determined in microbiological loads of the larvae. The characteristics of the insects revealed the great potential of these three species highlighting the capacities to respond to different requests derived from the food and feed sectors. Highlights Superworm larvae showed the highest content of SFA Mealworms larvae were the richest in PUFA The fat-soluble vitamin content followed the fatty acids content

Resistance to ß-cyfluthrin in populations of the pest lesser mealworm, Alphitobius diaperinus

Resistance to ß-cyfluthrin in populations of the pest lesser mealworm, Alphitobius diaperinus

The more, the better? Effect of density on the growth of the lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae)

Abstract Understanding the concept of larval density scaling in mealworm farming enables us to analyze and compare the growth patterns of these species and their overall productivity in terms of produced insect biomass. This paper explores the impact of larval density on the development of the lesser mealworm, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae). Seven different larval densities were examined in laboratory trials, ranging from 7.5 to 53 larvae per cm2, while the volumetric density per vial was consistent through the experiment at 10 larvae per cm3. The results showed a significant effect of larval density, restricted though to specific developmental traits of A. diaperinus larvae. Based on the results, the highest overall yield and biomass production was achieved at 53 larvae per cm2, however, this density resulted in prolonged development time and decreased larval growth and feed consumption metrics. It is suggested that a larval density of 30.3 larvae per cm2 could offer a favorable balance for achieving optimal biomass efficiency in terms of the time required for harvest, growth performance, feed utilization and economic feasibility. Nevertheless, to the best of our knowledge, this is the first work on the effect of larval density on the performance of A. diaperinus larvae and aims to contribute to the increase of the profitability of A. diaperinus mass-rearing production systems.

Lethal and sublethal effects of chronic exposure to insecticide residues on reared Alphitobius diaperinus

Abstract Edible insects such as lesser mealworm (Alphitobius diaperinus) are a promising new protein source for food and feed. The feed substrate on which these insects are reared may be contaminated with residues of insecticides originating from agricultural products that may impact insect performance. In this study, two generations of A. diaperinus were chronically exposed to spinosad (2.0 and 0.2 mg/kg) and imidacloprid (0.1 and 0.01 mg/kg) in the substrate. The aim was to determine sublethal effects on performance measures (total biomass (yield), mean individual weight, number of alive individuals) of larvae, pupae, and adult beetles, as well as pupation and eclosion. Exposure to spinosad at 2.0 mg/kg resulted in significant adverse effects on most performance measures of larvae, of both generations. Imidacloprid caused a reduction in yield and mean individual weight of the larvae as compared to the control at 0.1 mg/kg, while an increase in those measures was observed at 0.01 mg/kg. Significant adverse effects on adult beetles were only observed for imidacloprid at 0.1 mg/kg, and no significant effects of this insecticide on pupation and eclosion were observed. The concentrations of tested substances in larval samples were negligible for both generations, however, transfer from substrate to larval biomass was higher in the offspring generation relative to the parent generation. More research is needed to fully assess the hazard of insecticide residues to cause sublethal effects on A. diaperinus, for which method development for more cost-efficient designs is required.

Effect of temperature on the oviposition and egg hatching performance of Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae)

Abstract The commercial accessibility of insect biomass for food and feed necessitates a systematic examination of the various factors that can potentially hinder the efficiency of insect farming. This study focuses on identifying the optimal thermal requirements for the lesser mealworm, Alphitobius diaperinus (Panzer), an edible insect species of particular interest due to its significant potential as a food and feed source. Adults of the species were left to oviposit continuously for 45 days, under controlled laboratory conditions at 20, 25, 30 and 32 °C. The number of eggs laid by the adults, as well as the larval emergence was recorded during this period. Based on the findings, the reproduction output, expressed as the cumulative number of eggs per adult and the cumulative larval hatching rate, was affected by the temperature levels tested here. It has been determined that the optimal reproductive output of A. diaperinus can be attained by maintaining newly emerged adults within a temperature range of 25 to 30 °C for a period of 42 days. During this period, it is anticipated that each adult will yield an average of 73 eggs, while an estimated hatchability rate of 69 and 58% at 25 and 30 °C, respectively. Our study is one of the few that evaluate the efficacy of retaining parental adults of A. diaperinus for oviposition under commercial mass-rearing conditions, taking into account egg and larval production.

Lesser mealworm Alphitobius diaperinus (Coleoptera: Tenebrionidae) displays negative phototaxis and conditional hygrotaxis.

Arthropods use a variety of environmental cues to navigate between and locate hosts. In agricultural systems, clarifying the relevant cues and their effects on arthropod behavior can inform management practices to reduce or inhibit the activity of arthropod pests. The lesser mealworm Alphitobius diaperinus (Panzer) is a ubiquitous arthropod pest of broiler house chicken production, and while the patterns of movement and behavior of A. diaperinus are well documented, the specific environmental factors that govern these patterns are not known. We conducted behavioral assays testing the response of A. diaperinus adults and larvae to different wavelengths of light and to the presence of water. Alphitobius diaperinus displayed a significant repulsion from white, green, red, and blue light, while larvae consistently sought shelter and displayed no behavioral change in response to light. Dehydrated adult beetles displayed an attraction to water while hydrated beetles displayed a repulsion to water. Regardless of the availability of water, dehydrated beetles displayed a reduced repulsion from light. Taken together, these results indicate that A. diaperinus will hide from sources of light unless they are dehydrated. Knowledge of the environmental cues that influence the behavior of A. diaperinus could be used to improve methods of trapping, monitoring, and controlling populations of A. diaperinus in experimental and commercial settings.