Tenebrio Molitor Larvae Research Articles

Insect-based chitin and chitosan from whole body sources and rearing by-products: extraction, physicochemical, structural and bioactivity characterisation

Abstract Fractionation of edible insects and their rearing by-products can lead to expanded industrial applications and extraction of value-added products. The main goal of this study was to extract chitin and synthesise chitosan from three different insect sources – Tenebrio molitor larvae, adult Acheta domesticus and A. domesticus rearing by-products (legs and wings). Furthermore, the physicochemical, structural, and bioactive properties of insect-derived chitin and chitosan were characterised and compared to commercial crustacean-based samples. Chitin was isolated from defatted sources through chemical hydrolysis followed by decolourisation and was deacetylated with a strong alkaline solution to synthesise chitosan. Notably, A. domesticus rearing by-products yielded the highest chitin and chitosan content. Chitin and chitosan derived from insects exhibited physicochemical and structural characteristics consistent with the α-polymorphic form, similar to the commercial samples. Differences were found in surface morphology, with insect-derived samples presenting large and irregular flakes and porosity, while the crustacean-derived samples presented irregularly arranged fibres and a more regular and smoother surface. As for antioxidant activity, although all chitosan samples demonstrated poor DPPH radical scavenging activity, this study showed for the first time that insect-derived chitosan presents lipid peroxidation inhibition ability. All chitosan samples presented antimicrobial activity against different pathogenic bacteria, with K. pneumoniae being the most susceptible strain. Nevertheless, there is potential for enhancement of the biological properties through modifications on the molecular weight and deacetylation degree. This research introduces the potential of cricket-rearing by-products as sustainable sources of chitosan with functional bioactive properties.

Vismia guianensis Improves Survival of Tenebrio molitor and Mice During Lethal Infection with Candida albicans

Background/Objectives: Vismia guianensis is a vegetal species popularly used to treat fungal infections. This study evaluated the anti-Candida effect of V. guianensis extract after C. albicans lethal infection in Tenebrio molitor larvae and mice. Methods and Results: The chemical profile analysis of a hydroethanolic extract of the leaves of V. guianensis (EHVG) identified 14 compounds. Two sets of experiments used T. molitor larvae. To evaluate toxicity, the uninfected larvae were treated with EHVG or anthraquinone. We considered the following groups: the controls received PBS; ANFO B received amphotericin B (600 mg/mL); EHVG received the extract; and ANTQ received anthraquinone. The extract and anthraquinone resulted in low-level toxicity in the T. molitor larvae. Another set of experiments evaluated the EHVG effect during lethal infection with Candida albicans. The T. molitor larvae were treated intracelomically (ic/10 μL). Treatment with EHVG efficiently improved the survival of the larvae after lethal infection (60%), probably due to the reduction in CFUs. In the mice, the antifungal effect of EHVG was determined in three groups of immunosuppressed Swiss mice (cyclophosphamide, 50 mg/kg/ip) infected with C. albicans (1 × 107 CFU/ip). The control animals were infected and untreated; the ANFO B animals were infected and treated with amphotericin B (600 µg/kg/ip); and the EHVG animals were infected and treated with the extract (5 mg/kg/orally). A SHAM group (uninfected and untreated) was also included. Survival was assessed for 5 days. The extract increased the mice’s survival (60%) and life expectancy, reducing the CFU counts in the peritoneum and blood. EHVG also increased the number of blood neutrophils and peritoneal macrophages. These systemic activities are likely associated with the presence of flavonoids in the extract. Conclusions: The beneficial effects of EHVG in lethal sepsis are related to an antifungal effect, with the number of CFUs decreasing in the larvae and the mice. In addition, EHVG showed immunological activity in the mice, considering immune cell distribution and cytokine production.

Exploring the intricate studies on low-density polyethylene (LDPE) biodegradation by Bacillus cereus AP-01, isolated from the gut of Styrofoam-fed Tenebrio molitor larvae.

This study aims to investigate the biodegradation potential of a gut bacterial strain, Bacillus cereus AP-01, isolated from Tenebrio molitor larvae fed Styrofoam, focusing on its efficacy in degrading low-density polyethylene (LDPE). The biodegradation process was evaluated through a series of assays, including clear zone assays, biodegradation assays, and planktonic cell growth assessments in mineral salt medium (MSM) over a 28-day incubation period. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were employed to characterize the alterations in LDPE pellets, followed by molecular characterization. Over three months, sterile soil + LDPE pellets were treated with different concentrations of gut bacterial strain. The degradation capabilities were assessed by measuring pH, total microbial counts, carbon dioxide evolution, weight loss, and conducting phase contrast microscopy and mechanical strength tests. Results demonstrated that MSM containing LDPE as a carbon source with gut bacterial strain produced a clear zone and enhanced planktonic cell growth. FTIR analysis revealed the formation of new functional groups in the LDPE, while SEM images displayed surface erosion and cracking, providing visual evidence of biodegradation. Molecular characterization confirmed the strain as Bacillus cereus AP-01 (NCBI Accession Number: OR288218.1). A 10% inoculum concentration of Bacillus cereus AP-01 exhibited increased soil bacterial counts, carbon dioxide evolution, and pH levels, alongside a notable weight loss of 30.3% in LDPE pellets. Mechanical strength assessments indicated substantial reductions in tensile strength (7.81 ± 0.84 MPa), compression (4.92 ± 0.53 MPa), hardness (51.96 ± 5.62 shore D), flexibility (10.62 ± 1.15 MPa), and impact resistance (14.79 ± 0.94 J). These findings underscore the biodegradation potential of Bacillus cereus AP-01, presenting a promising strategy for addressing the global LDPE pollution crisis.

Safety of frozen and dried forms of whole yellow mealworm (Tenebrio molitor larva) as a novel food pursuant to Regulation (EU) 2015/2283.

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 the safety of frozen, dried and powder forms of whole yellow mealworm (Tenebrio molitor larva) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The term yellow mealworm refers to the larval form of the insect species T. molitor. The NF consists of the frozen and dried forms of the whole yellow mealworm. The frozen form mainly consists of water, crude protein, carbohydrates and fat, whereas the dried forms consist of crude protein, fat and carbohydrates. The Panel notes that the levels of contaminants in the NF highly depend on the occurrence levels of these substances in the insect feed. The Panel notes that there are no safety concerns regarding the stability of the NF if the NF complies with the proposed specification limits during its entire shelf life. The NF has a protein content that ranges between 13 and 48 g/100 g. The Panel acknowledges that the true protein content is 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 as food ingredient in various food products. The target population proposed by the applicant is the general population. Considering the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous. The Panel notes that no safety concerns arise from the toxicological information of the NF. The Panel considers that the consumption of the NF might trigger primary sensitisation to yellow mealworm proteins and may cause allergic reactions in subjects allergic to crustaceans, dust mites and molluscs. Additionally, allergens from the feed may end up in the NF. The Panel notes that allergic reactions may occur upon consumption. The Panel concludes that the NF is safe under the proposed uses and use levels.

Tenebrio molitor (Coleoptera: Tenebrionidae) as an alternative host for the study of pathogenicity in Candida auris

BackgroundCandida auris, a multidrug-resistant fungal pathogen, has emerged as a significant global health threat due to its high transmission and mortality rates, especially in healthcare settings. ObjectiveThis study aimed to establish the larvae of the coleopteran Tenebrio molitor (mealworm) as an in vivo model to evaluate the virulence of different C. auris strains. MethodsT. molitor larvae were inoculated with varying doses and strains of C. auris. Mortality rates were monitored, melanization responses, and phenoloxidase activity were assessed. Histopathological analyses were conducted to observe tissue invasion by the yeast cells. Additionally, a biofilm formation test was included as a complementary analysis to determine if biofilm production would influence the virulence of the C. auris strains. ResultsA dose-dependent increase in mortality was observed, with the highest fungal load leading to the highest mortality rates. The study also revealed significant differences in virulence among the strains, with those from Kuwait and the reference strain CBS 10913 showing the highest pathogenicity. Melanization rates were significantly higher in infected larvae, indicating an active immune response. The histopathological analysis revealed the presence of C. auris cells within the tissue of T. molitor larvae. However, the biofilm formation complementary test did not show a significant difference in virulence among the different clades of C. auris. ConclusionThe T. molitor model effectively demonstrated the pathogenic potential and virulence differences of C. auris strains. Strains from Kuwait and the reference strain CBS 10913 exhibited the highest virulence, causing 100% mortality within 24 hours. The model also highlighted significant biofilm formation and melanization responses, correlating with fungal burden. This insect model provides a valuable and cost-effective tool for preliminary virulence screening of clinical yeast strains, offering insights into host-pathogen interactions and the potential for evaluating antifungal treatments in vivo.

Rearing mealworm larvae with wheat, barley or maize grains as main source of nutrients in unbalanced or balanced substrates

Feeding conditions of mealworm (Tenebrio molitor) larvae for livestock nutrition needs to be optimized. The effects of the cereal offered as main nutrient source on growth performance and composition of T. molitor larvae were evaluated. In Experiment 1 (unbalanced diets), substrates included 80% of wheat (W1), barley (B1) or maize (M1) and 20% wheat straw. In Experiment 2 (balanced diets), substrates were formulated using wheat (W2), barley (B2) or maize (M2) as the main ingredient, combined with wheat bran or straw to contain similar N, starch and NDF contents (19.5, 520, and 270 g/kg DM, respectively). A control substrate based solely on wheat bran was also included in each experiment (C1 and C2). Each treatment was replicated four times in trays containing 24 g of substrate and 60 larvae, and the experimental period lasted for 28 (Experiment 1) or 35 (Experiment 2) days. Larval weight and residual substrate were monitored weekly, and larval chemical composition was analyzed at the end of each experiment. In Experiment 1, feed intake was greatest for B1 and W1, intermediate for C1 and lowest for M1 (P<0.001). However, larval growth was greater for C1 than for B1 and W1, with the lowest rates observed for M1 (P<0.001). Consequently, feed to gain (F:G) ratio was lowest for C1 and highest for M1 (P<0.001). Mortality was also greatest for M1 (P<0.001). In Experiment 2, feed intake (P<0.001) and larval growth (P<0.01) decreased in M2 compared to B2 and W2, which in turn showed similar growth performance to C2 (P<0.001). Larval composition followed a similar trend in both experiments, with the highest N content observed in larvae fed C1 and C2 (P<0.001), while DM and ether extract contents were higher in larvae reared on barley (P<0.001). In summary, maize-based substrates may compromise feed intake and growth performance of T. molitor larvae compared to those based on wheat or barley, regardless of the nutrient content of the diet. Apparently, larval performance does not respond to the substrate starch content but it might be influenced by the endosperm physical structure. Additionally, a lower N content in the substrate could impair growth performance, an effect that is alleviated once larval protein requirements are achieved. Larval composition was affected by the main dietary ingredient, with substrates based on wheat bran increasing the N content of larvae, whereas those based on barley resulted in increased DM and EE contents.

PHMB at 0.1% inhibits bacterial growth but does not eradicate biofilm or protect against infection in a Tenebrio molitor model

Biofilm in chronic wound is an important public health problem in several countries due its delayed healing and ineffective local treatment. Several treatments are employed to inhibit bacterial growth, among which polyhexamethylene biguanide (PHMB) stands out. PHMB is widely known for its antibacterial properties through mechanisms that include the interaction of this compound with bacterial cell walls and DNA. However, there are conflicting data regarding its activity in eradicating mature biofilm. The purpose of this study was to investigate the in vitro and in vivo anti-biofilm activity of the PHMB as well as its toxicity. Herein, we show that PHMB inhibits the bacterial growth in all concentrations, except for Klebsiella pneumoniae. We used a well-established biofilm model to quantitatively assess the eradication of organisms. PHMB at 0,1% did not eradicate biofilms of Enterococcus faecalis, Klebsiella pneumoniae and Staphylococcus aureus. In vivo testing of PHMB in Tenebrio molitor larvae infected with Enterococcus faecalis, Klebsiella pneumoniae and Staphylococcus aureus, this compound did not induce any toxicity, however it increased AST levels by around 600%. Furthermore, the PHMB did not improves larvae survival and did not reduce bacterial load in their hemolymph. We suggest that PHMB in this concentration may represent an alternative to treatment of infection in wounds, but not as a therapeutic alternative for wounds with biofilm.

Effect of Mn(II) and Co(II) on Anti-Candida Metabolite Production by Aspergillus sp. an Endophyte Isolated from Dizygostemon riparius (Plantaginaceae).

Background/Objectives: This study evaluates the effect of Mn(II) and Co(II) ions on the production of anti-Candida metabolites by the endophytic fungus Aspergillus sp., isolated from Dizygostemon riparius. The objective was to identify metal-induced secondary metabolites with antifungal potential against drug-resistant Candida species. Methods: Aspergillus sp. was cultivated in Czapek agar supplemented with MnCl₂ (400 µM) or CoCl₂ (200 µM). Metabolite profiles were analyzed using UHPLC-DAD and LC-ESI-HRMS, followed by structural elucidation via NMR. Antifungal and biofilm inhibition activities were tested against Candida albicans and Candida parapsilosis. Toxicity was assessed using Tenebrio molitor larvae. Results: Key metabolites, including pyrophen, penicillquei B, and fonsecinone B, demonstrated antifungal activity with MIC values of 4.37-280.61 µg/mL. Fonsecinone B exhibited superior biofilm inhibition, surpassing fluconazole in reducing biofilm biomass and viability. In vivo assays showed low toxicity, with survival rates above 80% at 2× MIC/kg. Conclusions: Mn(II) and Co(II) significantly modulated the production of antifungal metabolites in Aspergillus sp. Fonsecinone B emerged as a promising candidate for antifungal therapy due to its potent activity and low toxicity. These findings support further investigation into the therapeutic potential of metal-induced fungal metabolites for combating drug-resistant Candida infections.

Bread By-Product and Maize Silage as Alternative Ingredient Feeds for Production of Tenebrio molitor Larvae in High-Concentrate Substrates.

Bread by-product and maize silage as substrates for Tenebrio molitor larvae were studied in four isonitrogenous diets: a control substrate (CTL) made of wheat grain, wheat bran, and soybean meal and three diets where wheat grain and wheat bran were partly substituted with bread by-product (BBP) or with this and either a low (MSL) or high (MSH) proportion of maize silage (170 or 310 g/kg, respectively). Larval weight was weekly monitored, and the chemical composition of larvae and residual substrates was analyzed at the end of the experiment. Larvae fed CTL and BBP grew more than those fed MSL and MSH (p < 0.001). Feed intake was greatest for BBP (p < 0.001), and consequently, feed-to-gain ratio (F:G) was better for larvae fed CTL than BBP, and better for BBP than MSL and MSH (p < 0.001). Besides, total production of crude protein and ether extract were greater for CTL and BBP than for MSH and MSL (p < 0.001). The inclusion of bread by-product in the substrate did not affect growth performance, whereas diets including maize silage impaired larval growth, substrate intake, and F:G. Both by-products can be advantageously used for feeding T. molitor larvae, but the impairments in growth performance should be considered to optimize production costs.

Exploring the Potential of Yellow Mealworm (Tenebrio molitor) Oil as a Nutraceutical Ingredient.

During defatted Tenebrio molitor (TM) larvae powder production, oil is obtained as a by-product, mainly intended for feed enrichment or as a biofuel component. In 2021, EFSA authorized TM as the first insect to be a novel food. Thus, the study aimed to assess the composition, including fatty acids (FAs), tocopherols, carotenoids, phenolics, volatiles, antioxidant capacity, sensory aroma attributes, physical properties, and oxidative and hydrolytic stability of TM oil. The FAs profile was dominated by oleic-C18:19c (36.8%) and linoleic-C18:29c12c (32,4%) acids, resulting in a PUFA/SFA ratio similar to vegetable oils. Thus, TM oil was characterized by a beneficial Health Promoting Index (HPI) (2.42), which was 10-fold higher than the HPI of common animal fats. TM oil contained bioactive compounds such as carotenoids (13.65 mg/kg), tocopherols (105.8 mg/kg), and phenolic compounds (74 mg GAE/kg). A noticeable amount of apigenin was also noted among nine detected phenolic compounds. The substantial presence of lipophilic and phenolic compounds contributed to antioxidative potential. Sensory estimation revealed the dominance of fried and nutty aromas, probably because of the abundance of Strecker aldehydes and pyrazines in their volatile profile. The results indicated that the technological process needs modification to limit the formation of lipid oxidation volatile compounds such as aldehydes and eliminate some differences between batches. This preliminary study on the composition and properties of TM oil encourages its use as an ingredient for food, pharmaceutical, and cosmetics purposes.

Inclusion of Tenebrio molitor larvae meal in the diet of barbary partridge (Alectoris barbara) improves caecal bacterial diversity and composition

In this study, we investigated the influence of the inclusion of Tenebrio molitor (TM) larvae meal in the diet on the diversity and structure of the bacterial community in the caecal content of Barbary partridges. A total of 36 partridges, selected randomly for slaughter from 54 animals, were divided equally into three treatment groups, including the control group (C) with a diet containing corn-soybean meal and two experimental groups, in which 25% (TM25) and 50% (TM50) of the soybean meal protein was replaced by the meal from TM larvae. After slaughtering, the bacterial community of the 30 caecal samples (10 samples per each experimental group) was analysed by high-throughput sequencing using the V4–V5 region of the 16 S rRNA gene. Alpha diversity showed a higher diversity richness in the TM50 group. Beta diversity showed statistical dissimilarities among the three groups. Firmicutes was the dominant phylum regardless of the diet, with the predominant families Ruminococcaceae and Lachnospiraceae. Clostridia and Faecalibacterium were decreased in both TM groups, Lachnospiraceae was suppressed in the TM50 group, but still this class, genus and family were abundantly present in all samples. Several potentially beneficial genera, such as Bacillus, Ruminococcaceae UCG-009, Oscillibacter and UC1-2E3 (Lachnospiraceae) were increased in the TM50 group. The results showed a beneficial effect of the T. molitor larvae meal on the caecal microbiota of Barbary partridges, particularly in the TM50 group, which showed an increase in bacterial diversity.

Evaluating Tenebrio molitor (Coleoptera: Tenebrionidae) for the reduction of fumonisin B1 levels in livestock feed.

The yellow mealworm, Tenebrio molitor, L., can be an important component of the circular economy because of its ability to transform a variety of agricultural wastes and byproducts into valuable livestock feed. Analysis of their ability to endure toxins coupled with their potential to transfer contaminants to higher trophic levels is not complete. Fumonisins, produced primarily by Fusarium verticillioides (Hypocreales: Netriaceae) (Sacc.) Nirenberg (1976), are mycotoxins likely to be encountered by T. molitor in corn and other grain byproducts. Tenebrio molitor larvae were reared on a simulated diet of corn and other grain byproducts treated with a range of maximum recommended fumonisin B1 levels for different livestock feeds. We observed that T. molitor were able to survive, grow, and reduce by excretion and metabolism their retained fumonisin B1 levels by up to 99.7% compared to the diet they consumed. Unknown metabolic processes were inferred from the significantly reduced content of fumonisin B1 in the frass (63.1% to 73.2%) as compared to the diet and by the first report of long-chain acylated fumonisin B1 derivatives in insect frass.

Microbiota modulation by the inclusion of Tenebrio molitor larvae as alternative to fermented soy protein concentrate in growing pigs diet.

Tenebrio molitor meal represents a promising protein source for animal nutrition due to its low environmental impact and high nutritional value. To date, there is limited data in the literature regarding the effects of Tenebrio molitor meal on the modulation of gut microbiota in growing animals, with most results focusing on poultry rather than pigs. The aim of this study was to evaluate the effects of replacing fermented soy protein concentrate with Tenebrio molitor meal on gut microbiota and feed digestibility in growing pigs. A total of 14 growing pigs (80 ± 2 days old) were randomly allotted to two groups: the control group (CON) was fed a commercial diet containing 4% fermented soy protein concentrate (48% crude protein), and the treatment group (TM) was fed a basal diet containing 5% of T. molitor larvae meal formulated to be isonitrogenous and isoenergetic. The study lasted 28 days. Animals were weekly weighted and feed refuse was routinely measured. Fecal, blood samples, and rectal swabs were collected for analysis. No differences were observed in growth and diet digestibility for the protein and lipid components throughout the trial. No differences in the serum concentrations of albumin, globulin, urea, and interleukin-6 were registered in both groups, suggesting an unaltered health status. The TM group showed a significant difference in the beta diversity index considering the total duration of the trial (treatment effect evaluated with PERMANOVA, R2 0.0771, p value = 0.0099) showing an increased abundance of Elusimicrobium spp. and a decrease in Asteroplasma spp. in TM compared to the CON group (p < 0.05). Obtained findings indicate that 5% T. molitor meal can be included as a partial replacement for soy in growing pig formula without impairing pig growth and gut microbiota composition.

Nutritional ecology of a predatory stink bug: A comparative analysis of nutrient acquisition from two prey species and an artificial diet

The nutritional content of prey plays a pivotal role in shaping the predatory behavior and effectiveness of natural pest control agents like Eocanthecona furcellata. We assessed the biological performance and life history of E. furcellata on three diets, larvae of Spodoptera frugiperda, larvae of Tenebrio molitor, and an artificial diet. We also analyzed their nutritional content and quantified consumption and nutritional intake by E. furcellata. The three diets differed substantially in water, protein, and fat content. The moisture content of T. molitor larvae was significantly lower (35.0 ± 0.3 %) than that of S. frugiperda larvae (61.0 ± 0.6 %) or the artificial diet (88.7 ± 0.1 %). Female E. furcellata obtained 8.3 mg of protein per day feeding on S. frugiperda, significantly more than on T. molitor (2.4 mg) or the artificial diet (0.4 mg). 15-day fecundity ranged from 140.2 (±9.3) eggs on S. frugiperda, to 103.3 (±4.8) eggs on T. molitor, and 75.1 (±7.1) eggs on the diet. Our study provides insights into the nutritional ecology of E. furcellata and ways to improve the breeding of this beneficial species for augmentation in agricultural applications.

N -butanol fraction of Terminalia catappa possesses anti-Candida albicans properties and in vivo action on Tenebrio molitor alternative infection model

Current treatment of Candida infections is threatened by antifungal drug resistance. Thus, medicinal plants have been studied to identify new and highly effective antifungal substances with low toxicity. Here, we showed that the tannin-rich n-butanol fraction of Terminalia catappa (FBuOH) possesses antifungal and antibiofilm properties and protects Tenebrio molitor larvae against Candida albicans infection. FBuOH showed antifungal activity against Candida spp. vaginal isolates (MIC values ranged from 7 to 500 μg/mL). Moreover, a combination of FBuOH with fluconazole (FICI ≤0.5) showed considerably increased anti-yeast, anti-biofilm activity and significantly improved the survival rate (up to 100 %) of T. molitor larvae against C. albicans infection. Furthermore, FBuOH acted synergistically with fluconazole by reducing C. albicans membrane ergosterol content. These results could also explain the synergistic activity between FBuOH and fluconazole, indicating that FBuOH exerted its effects on C. albicans membrane integrity, increasing its permeability. Our findings provide insights into the antifungal activity and low cytotoxicity of FBuOH, showing its potential use as a new antimycotic.

Production, Characterization and Application of Biosurfactant for Cleaning Cotton Fabric and Removing Oil from Contaminated Sand

Biosurfactants are a group of environmentally friendly amphiphilic molecules that are applicable in numerous industries as essential biotechnology products, such as food production, cleaning products, pharmacology, cosmetics, pesticides, textiles and oil and gas fields. In this sense, and knowing the potential of these biomolecules, the aim of this work was to produce a biosurfactant, characterize it regarding its chemical and surfactant properties and investigate its potential in the removal of contaminants and in the cleaning of cotton fabrics. The biosurfactant was initially obtained from the cultivation of the microorganism Candida glabrata UCP 1002 in medium containing distilled water with 2.5% residual frying oil, 2.5% molasses and 2.5% corn steep liquor agitated at 200 rpm for 144 h. The biosurfactant reduced the surface tension of water from 72 to 29 mN/m. The toxicity potential of the biosurfactant was evaluated using Tenebrio molitor larvae and demonstrated non-toxicity. The biosurfactant was applied as a degreaser of engine oil on cotton fabric, and showed 83% (2× CMC), 74% (1× CMC) and 78% (1/2× CMC) oil removal. Therefore, the biosurfactant produced in this work has promising surfactant and emulsifying properties with potential for application in various industrial segments.

Evaluation of carrot and agroindustrial residues for obtaining Tenebrio molitor (yellow mealworm) powder enriched in bioaccessible provitamin A and colourless carotenoids

In this pilot study Tenebrio molitor larvae were fed with two residues (olive leaf meal and spent Pleurotus ostreatus substrate meal) and wheat flour (control). Carrot was used to provide a source of water and carotenoids. The objectives were to compare the effect of residues on growth and proximate composition of the flours and their carotenoid profile, by providing carotenoids and/or affecting their absorption by larvae. Additionally, the carotenoid bioaccesible content in Tenebrio molitor powder was evaluated. The powder obtained from larvae fed with the residues had a similar proximal composition to the control and residue meals tested did not affect negatively larval survival nor growth. Larvae accumulated significant amounts of carotenoids, especially when fed with olive leaf meal, followed by spent Pleurotus ostreatus substrate meal, even though the latter lacked detectable amounts of carotenoids. This suggests that the composition of the fungal substrate may favour a higher carotenoid uptake mechanism in mealworms compared to control. The colourless carotenoids phytoene and phytofluene exhibited the highest carotenoid bioaccesible content, followed by the provitamin A carotenoids β-carotene and α-carotene. Summarizing, T. molitor fed on agri-food residues can accumulate bioavailable and health-promoting carotenoids, that can contribute to alleviating global problems such as vitamin A deficiency.

From insects to mammals! Tissue accumulation and transgenerational transfer of micro/nano-plastics through the food chain

Despite extensive global attention on microplastic pollution, our understanding of the pathways underlying microplastic translocation, accumulation, and their potential impacts on ecosystems and human health through the food chain remains incomplete. To investigate the translocation and accumulation of microplastics from insects to mammals, we developed a novel oral exposure model that Tenebrio molitor larvae (yellow mealworms, invertebrate terrestrial insects) were firstly orally exposed to both micro and nanometer-sized plastics (M/NPs), and subsequently fed as a food source to mice (mammals). Our results provide clear evidence that micro/nanoplastics (M/NPs) do indeed translocate through the food chain, from lower to higher trophic levels. Fluorescence microscopy and tissue quantification revealed the accumulation of M/NPs in the digestive, somatic, and circulatory systems of the larvae. Specifically, the food chain transferred M/NPs were later detected in the digestive, respiratory, and urinary systems of mice, showcasing strong fluorescent signals in vital organs such as the lungs, liver, intestines, brain, and kidneys, as well as in embryos. These findings highlight the intricate dynamics of M/NPs contamination, emphasizing their ability to traverse biological barriers, accumulate in organisms, and potentially impact embryonic development via food chain transfer.

Whitefly‐Pathogenic Beauveria bassiana JEF‐507 as a Competitive Biopesticide, Chongchae‐Stop

ABSTRACTSilverleaf whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is a destructive insect pest damaging to diverse crops by vectoring several plant pathogenic viruses, which consequently causes economic losses in crop production. As the resistance of whiteflies to chemical insecticides is increasing, this study aimed to investigate the potential of entomopathogenic fungi as an alternative. A total of 72 entomopathogenic fungal isolates, collected from soils using Tenebrio molitor larvae as an insect baiting method, were assessed for their virulence against 2nd nymphs of whitefly. Their virulence was assayed by dipping whitefly‐infested tomato leaves in fungal conidia suspensions at 1.0 × 107 conidia/mL. Among the tested isolates, two isolates of Beauveria bassiana JEF‐462 and JEF‐507 showed high virulence. In the assessment of virulence depending on conidia concentrations, the estimated LC50 values for JEF‐462 and JEF‐507 were similarly 8.7–14.0 × 107 conidia/mL. However, B. bassiana JEF‐507 showed higher conidial productivity and thermotolerance on most of tested 12 grain substrates than B. bassiana JEF‐462, and millet was the most suitable grain substrate. Additionally, siloxane as a surfactant was able to sufficiently exhibit the insecticidal activity of JEF‐507 against whitefly nymphs compared with other surfactants. In a pot‐based greenhouse trial, JEF‐507 showed higher control efficacy than chemical insecticides, dinotefuran and spinetoram. This work suggests that B. bassiana JEF‐507 could be competitively used as a biopesticide to control silverleaf whiteflies while overcoming current resistance issues. The JEF‐507 isolate has been registered in Korea, 2022 and successfully commercialised as the name of Chongchae‐Stop in this local market to control whitefly and thrips.

Make it a standard? The creation and variability assessment of a consensus standard protocol for Tenebrio molitor larvae feeding trials

Abstract Interest in the nutrition of the yellow mealworm (Tenebrio molitor L.) larvae is on the rise, leading to an increase in publications on this topic. The absence of a standard protocol and resulting differences in experimental designs reduces comparability among studies and impedes research on mealworm nutrition. To address this, a consensus standardised protocol was developed specifically for the evaluation of mealworm larval growth and performance in feeding trials. The efficacy of this protocol was evaluated through an international ring test involving seven partners using two wheat brans as dry feed (a standard bran and a local bran) at 27 °C and 60% relative humidity. As experimental units, plastic crates filled with 2.1 kg of bran and 10,000 4-week-old larvae were used with six replicates. Agar gel was provided as wet feed ad libitum. The mean individual larval weight and the number of larvae per crate were determined weekly until either three or more replicates ran out of feed or pupation exceeded 10%. At harvest, the total larval fresh biomass and amount of frass was determined. Larval samples were taken for chemical analysis. To assess the protocol, the within (repeatability) and between (reproducibility) laboratory variability was calculated for each parameter. The repeatability was good (limit at 12% (standard) and 14% (local)). The reproducibility was poorer with a limit 2.7 times higher for the standard feed (36%) and 3.8 times higher for the local feed (55%). For both feeds, the total larval fresh harvest, amount of frass and the larval protein concentration were the most consistent both within and among laboratories. The highest variability was observed at the early life stages and for the larvae ash content. The detailed consensus standard protocol and repeatability/reproducibility estimates can be used as basis for future mealworm feeding trials, comparing results and future improvements.