Search Results (48)

Crickets use the pulse pattern of the species-specific calling song as a primary cue for mate recognition. Here we combined transcriptome profiling of brain regions with network-based analyses in Gryllus bimaculatus exposed to silence or pulse trains known to elicit strong or weak phonotactic attraction. Acoustic stimulation triggered specific transcriptional changes in the brain, with the anterior protocerebrum showing the most pronounced and selective responses to the calling song pattern, characterized by enrichment in neuromodulatory and neurotransmitter-related pathways. Weighted gene co-expression analysis identified a specific cluster of highly co-expressed genes in the anterior brain (termed the calling song-responsive module) that responded selectively only to the calling song stimulus. Genetic network topology analysis revealed six highly connected key hub genes within the calling song-responsive module—GbOrb2, Gbgl, Gbpum, GbDnm, GbCadN, and GbNCadN. These genes showed extensive interactions with many other genes in the network, suggesting their central regulatory role in response to calling song in female crickets. These findings support the anterior brain as a central integrator of cricket auditory mate recognition cues and point to a core molecular network that likely underpins this behavior. Full article

The scarlet gene encodes an ATP-binding cassette transporter involved in eye pigmentation across various insect species. In this study, we functionally characterized the scarlet homolog (Gbst) in the cricket Gryllus bimaculatus, a hemimetabolous model organism. Clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9-mediated knockout of Gbst generated a stable yellow-eyed mutant line (Gbst^−/−) with changed pigmentation evident from embryogenesis through adulthood. Quantitative real-time PCR analysis showed that scarlet expression was extremely low in Gbst^−/−, and the transcript levels of white and brown were also reduced. Histological sections of the compound eyes showed that both WT and Gbst^−/− mutant possessed complete and well-defined ommatidial structures, indicating that the scarlet gene does not affect compound eye structure. In addition, reproduction tests showed that knockout of the Gbst gene did not affect egg production or embryonic viability. These findings demonstrate that Gbst is a key factor involved in eye pigmentation in G. bimaculatus, and has potential for application as a visual transgenic marker gene. Full article

As demand for sustainable protein intensifies, edible crickets offer a promising solution to food insecurity and environmental strain, particularly in regions like Madagascar. This study investigated the effects of two rearing temperatures (28 °C and 30 °C) on life-history traits of three edible cricket species—Gryllus bimaculatus, Gryllodes sigillatus, and Teleogryllus lemur—under controlled laboratory conditions. Growth, survival, development time, and biomass yield were quantified for each species (n = 150 per temperature treatment) and analyzed using t-tests, chi-squared tests, and ANOVA. Results revealed distinct species-specific thermal responses. G. bimaculatus exhibited accelerated development and higher biomass at 30 °C without significant survival loss. G. sigillatus maintained high survival but developed more slowly at 30 °C, suggesting thermal sensitivity. In contrast, T. lemur demonstrated substantial growth gains at 30 °C but suffered a 50% reduction in survival, indicating heat intolerance. Development time and biomass yield varied significantly across species and temperature treatments (p < 0.0001). These findings highlight critical trade-offs between growth efficiency and survival in insect farming systems. G. bimaculatus emerges as a strong candidate for high-yield, thermally resilient farming, while T. lemur requires cooler rearing environments. This work informs species selection and environmental optimization for scalable, climate-adaptive cricket farming in tropical regions. Full article

Insect phonotaxis is influenced by various external and internal factors related to the environment and to the inner states of an organism. Previously, we found that flight, a natural behavior common among insects, significantly enhances the subsequent phonotactic response of female crickets (Gryllus bimaculatus) via serotonergic mechanisms. It is known that phonotaxis is also present in male crickets. However, the natural factors influencing phonotaxis in males and the neurochemical mechanisms behind these effects remained unknown. Our goal was to clarify these points and to compare phonotaxis of freely moving male and female crickets using a recently developed experimental paradigm. First, we found that freely moving male and female crickets demonstrate similar phonotactic response, quantitatively evaluated based on the time that animals spent near the source of calling song, their average distance to it and the number of approaches to it. We also found that the experience of previous flight increased phonotaxis in male crickets as it does in females. Also, as in females, this effect was associated with serotonergic neurotransmission. Thus, the manifestation of phonotactic behavior in freely moving male and female crickets, as well as the behavioral and monoaminergic modulation of phonotaxis in both sexes, appear to be quite similar in our experimental paradigm. Full article

This study aimed to evaluate the effects of three drying methods, namely sun drying, microwave–vacuum drying, and hot-air-oven drying, on the physical and nutritional properties of cricket powder for use in poultry feed. The results showed that the drying method significantly affected color parameters (L*, a*, and b*; p < 0.05), and particle size distribution at 850 µm and 250 µm (p = 0.04 and p = 0.02, respectively). Microwave–vacuum drying produced the lightest powder with a higher proportion of coarse particles, while sun drying resulted in a darker color and greater particle retention at 850 µm. Hot-air-oven drying yielded the lowest moisture content (1.99%) and the highest gross energy (6126.43 kcal/kg), with no significant differences observed in crude protein (p = 0.61), ether extract (p = 0.08), crude fiber (p = 0.14), ash (p = 0.22), or amino acid profiles (p > 0.05). These findings indicate that all drying methods preserved the nutritional value of cricket powder, and based on the overall results, hot-air-oven drying is the most suitable method for producing high-quality cricket meal with optimal physical properties and feed value, while also providing a practical balance between drying efficiency and cost. Full article

Watermeal (Wolffia globosa) is an emerging sustainable feed ingredient, valued for its rapid growth, high protein content, and rich nutrient profile, offering great potential to improve the efficiency and sustainability of edible cricket production systems through efficient resource use and reduced environmental impact. This study aimed to evaluate the effects of replacing commercial cricket feed with dried watermeal and to determine the optimal substitution level for the production performance of two-spotted crickets (Gryllus bimaculatus). Seven dietary treatments were tested, namely 0% (control; T1), 10% (T2), 25% (T3), 50% (T4), 75% (T5), 90% (T6), and 100% (T7). Crickets were reared for four weeks in an open system with 6 replicates per treatment, with each containing 120 nymphs. Body weight, feed intake, and survival rate were recorded weekly, and a production index was calculated at the end of the trial. Results showed average growth rates ranging from 7.40 to 28.20 mg/day, feed conversion ratios (FCR) between 1.03 and 1.68, survival rates of 29.28% to 69.73%, and production index values from 24.00 to 128.30. A significant decline in production efficiency (p < 0.05) was observed at substitution levels of 75% and above, with the 100% watermeal group showing the lowest production efficiency (p < 0.05), likely due to nutrient imbalances and indigestible compounds. Segmented regression analysis identified 36.7% as the optimal level of watermeal supplementation. In terms of body composition, crickets fed diets containing up to 50% watermeal (10%, 25%, and 50%) showed crude protein, crude fat, crude fiber, and ash contents comparable to those fed the commercial diet. This finding suggests that dried watermeal can replace up to 50% of the commercial cricket feed without negatively affecting growth performance, survival, or nutritional quality, with 36.7% identified as the optimal replacement level for maximizing production efficiency. Full article

To mitigate consumer aversion toward edible insects, it is essential to determine the optimal level of insect powder by considering consumer acceptability. In this study, gluten-free (GF) chocolate cookies were manufactured using 3D printing with varying concentrations (0, 3, 6, 9, 12, and 15%) of Gryllus bimaculatus (GB) powder. Physicochemical properties, sensory perception using rate-all-that-apply questions, and consumer acceptability using survival analysis were evaluated. The effects of GB powder concentration on the proximate composition, pH, color attributes, physical properties, 3D printing performance, and post-processing of the cookies were analyzed and discussed. As the concentration of GB powder increased, crude protein, ash, crude fat, a*, and mechanical force increased, while L*, b*, and the pH of both the dough and cookies decreased. Consumer tests showed a negative correlation between GB concentration and consumer acceptability, with cookies containing 3% GB receiving the highest overall liking scores. Principal component analysis and partial least squares regression showed that lower GB levels enhanced positive sensory attributes such as sweetness, chocolate flavor, and moistness, whereas higher levels intensified bitter taste and astringency, contributing to reduced acceptability. According to survival analysis, the GB concentration at which 50% of consumers were predicted to reject the product was estimated at 5.23%, indicating the necessity to limit GB incorporation below this threshold to ensure consumer acceptance. This study provides a comprehensive understanding of the quality characteristics and consumer acceptability of insect-based GF cookies, offering valuable insights for future product development and market applications. Full article

Background/Objectives: Obesity-related metabolic complications contribute to musculoskeletal disorders and are often associated with muscular fat accumulation. The AMP-activated protein kinase (AMPK) is a therapeutic target that can mitigate these effects. Methods: An in vivo study was conducted to understand the effects of Gryllus bimaculatus (GB), a potent AMPK activator, on metabolic and muscular homeostasis in diet-induced obesity (DIO). Six-week-old male C57BL/6J mice were fed either a normal diet or a high-fat diet (HFD) for eight weeks to induce DIO. Subsequently, HFD-fed mice were divided into four groups: HFD only, HFD with 100 mg/kg/day GB, HFD with 200 mg/kg/day GB, and HFD with 400 mg/kg/day GB for 16 weeks. To assess the effects of GB, we evaluated insulin resistance, muscle strength, muscular fat accumulation, and AMPK activation using an oral glucose tolerance test, grip strength test, histological assessments, serum lipid analyses, western blotting, and quantitative reverse transcription–polymerase chain reaction. Results: The low- and mid-dose GB groups showed a trend toward improved insulin resistance. GB significantly reduced muscle fat accumulation and increased muscle strength. The mid- and high-dose GB groups showed a significantly upregulated expression of the molecular markers of mitochondrial biogenesis and fatty acid oxidation in muscle tissues. Additionally, the high-dose GB group activated AMPK and inhibited the activity of acetyl-CoA carboxylase in the skeletal muscle. Conclusions: The results suggest that GB may serve as a nutraceutical candidate for the management of obesity-associated metabolic complications. Full article

Background/Objectives: Crickets are recognized as an alternative source of chitosan. This study aimed to assess the potential of cricket-derived chitosan as a natural source to develop chitosan nanoparticles (CNPs). Methods: Chitosan were isolated from different cricket species, including Gryllus bimaculatus, Teleogryllus mitratus, and Acheta domesticus. The isolated chitosan were characterized by their functional groups, crystallographic and thermal properties, molecular structure, morphology, water solubility, molecular weight, binding capacity, irritation potential, and cytotoxicity in comparison to commercial shrimp-based chitosan. CNPs were developed through an ionotropic gelation method, followed by the evaluation of particle size, polydispersity index (PDI), and zeta potential. Results: The findings of this study indicate that chitosan can be successfully isolated from the three cricket species, with yields ranging from 4.35% to 5.22% w/w of the dried material. The characteristics of cricket-based chitosan were similar to those of commercial chitosan, except that the cricket-based chitosan displayed a higher crystallinity and a lower molecular weight. Additionally, CPNs were successfully produced from cricket-based chitosan using sodium citrate as a crosslinking agent. All cricket-based chitosan exhibited no irritation or cytotoxicity. Chitosan derived from A. domesticus however was found to be the most suitable to develop CPNs, as it produced the smallest particle size (522.0 ± 12.1 nm) with a comparatively narrow PDI (0.388 ± 0.026) and an acceptable positive zeta potential (34.2 ± 4.4 mV). Conclusions: Cricket-derived chitosan compares favorably with crustacean-derived chitosan and showed potential for a range of applications, including the use as a nanocosmeceutical delivery system in topical and cosmetic formulations. Full article

The potential range and distribution of insects are greatly impacted by climate change. This study evaluates the potential global shifts in the range of Gryllus bimaculatus (Orthoptera: Gryllidae) under several climate change scenarios. The Global Biodiversity Information Facility provided the location data for G. bimaculatus, which included nineteen bioclimatic layers (bio01–bio19), elevation data from the WorldClim database, and land cover data. For the near future (2021–2040) and far future (2081–2100) under low (SSP1-2.6) and high (SSP5-8.5) emission scenarios, the Beijing Climate Center Climate System Model (BCC-CSM2-MR) and the Institute Pierre-Simon Laplace Coupled Model Intercomparison Project (IPSL-CM6A-LR) were used. Assessing habitat gain, loss, and stability for G. bimaculatus under potential scenarios was part of the evaluation analysis. The results showed that the main environmental parameters affecting the distribution of G. bimaculatus were mean temperature of the driest quarter, mean diurnal temperature range, isothermality, and seasonal precipitation. Since birds, small mammals, and other insectivorous insects rely on G. bimaculatus and other cricket species as their primary food supply, habitat loss necessitates management attention to the effects on the food web. The spread of G. bimaculatus as a sentinel species in the food chain and its use in animal feeds are both impacted by habitat loss and gain. Full article

Unconventional protein sources are currently extensively studied as food ingredients. This study aimed to evaluate the effect of 1.5% and 3% field cricket powder (GB) and 2–8% of its mixture (1:1) with spirulina powder (S) on the nutritional value, physicochemical properties, and sensory characteristics of corn extrudates. Additionally, 2% baking powder (BP) was added to assess its impact on the properties of the enriched extrudates. The results showed that both GB and GB + S improved nutritional value, with protein content increasing by up to 46% and higher levels of essential amino acids, particularly leucine and valine. However, these ingredients decreased the expansion ratio (by up to 15%), colour lightness (by up to 30%), and yellowness (by up to 47%) and increased the hardness (by up to 25%) of the corn extrudates. The S addition positively influenced product storage stability but decreased its sensory acceptance, especially aroma and taste. The BP addition mitigated the negative effects of higher GB and GB + S concentrations, particularly on sensory characteristics. In conclusion, incorporating up to 6% of the GB + S mixture provides a higher protein content with only minor changes to the product’s characteristics compared to GB. Ratings exceeding 4.2 points indicate the good acceptability of these snacks. Full article

This study aimed to determine the influence and optimal conditions of incubation temperature and relative humidity (RH) on the egg hatchability patterns of two-spotted (Gryllus bimaculatus) and house (Acheta domesticus) crickets. Experiment I involved 100 cricket eggs per hatching box for each species, with six replications for each controlled incubation temperature of 23, 25, 27, 29, 30, 31, 32, and 33 °C at 70% RH. Experiment II used all the same procedures as Experiment I, except for incubation temperatures of 29, 30, 31, and 32 °C tested with varied RH levels of 65%, 70%, and 75%. In Experiment I, two-spotted crickets (9.47 ± 1.99 days) exhibited faster hatching than house crickets (13.70 ± 2.78 days). Additionally, the onset of hatching decreased with higher incubation temperatures for both types of crickets. In Experiment II, an incubation temperature of 31 °C and 70% RH resulted in a hatching rate of 79.75% for two-spotted crickets, with hatching beginning in 6 days. For house cricket eggs, the optimal conditions of 30 °C and 65–75% RH led to a peak daily hatching rate of 62.00–65.50% and hatching onset in 12 days. Thus, this study established the optimal incubation temperature and RH for egg hatching of two-spotted and house crickets. Full article

Food safety for cricket production is a crucial factor in producing edible crickets with safety for consumers and sustainability for two-spotted (Gryllus bimaculatus) as well as house (Acheta domesticus) cricket production. This study was conducted by simultaneously rearing two cricket species, comprising two-spotted crickets (G. bimaculatus) and house crickets (A. domesticus). A total of 16 rearing crates were used for the present study, which were allocated into 8 rearing crates for each studied cricket species, including paper egg cartons. Cricket eggs were incubated in the rearing crates. Once the crickets hatched, tap water and powdered feed were provided ad libitum throughout the experiment. At the end of this study (35 and 42 days for the two-spotted and house crickets, respectively), all crickets were harvested, rinsed in tap water, and boiled in water for 5 min. During the rearing and harvesting processes, samples were collected from various potential contamination points for bacteria, including E. coli and Salmonella spp. There were samples of the initial input (feed, drinking water, and staff hands), rearing environment (water pipe, crate wall, living cartons, frass, and cricket surface), and harvesting crickets (harvested, washed, and boiled crickets), with a 2-week sampling interval, except for the last round of sampling for the two-spotted crickets. Subsequently, all samples were submitted to isolate and identify contaminated bacteria. The samples from the last round of sampling for both kinds of crickets were submitted to quantify the level of contamination for E. coli and Salmonella spp., including antimicrobial resistance by the disk diffusion method for the positive isolate. The results showed that bacterial contamination was found in the rearing of both cricket species, primarily involving Klebsiella spp. and Enterobacter spp., mainly found in prepared drinking water and the water pipes of drinking water supply equipment, which are potential sources of contamination with cricket frass. E. coli was found in 4.8% and 4.3% of the two-spotted and house crickets, respectively, while no presence of Salmonella spp. was detected in any submitted samples. The quantification of E. coli and Salmonella spp. indicated E. coli contamination near the water pipe and the frass of two-spotted crickets, but Salmonella spp. was undetectable in both two-spotted and house crickets. The antimicrobial resistance of isolated E. coli mainly involved penicillin G, amoxicillin, ampicillin, erythromycin, lincomycin, and tiamulin. Thus, good farm management with proper sanitation practices (such as cleaning and keeping the environment dry), as well as boiling crickets during the harvesting process, may help ensure the safety of edible cricket production. Full article

Cordyceps militaris, well known for its therapeutic potential in managing type-2 diabetes through the inhibition of α-amylase and α-glucosidase enzymes, was the central focus of this research, which investigated the influence of various cultivation substrates on its enzymatic inhibitory properties and bioactive compound content. Previous studies have primarily focused on the general pharmacological benefits of C. militaris but have not thoroughly explored how different substrates affect its bioactive profile and enzyme inhibitory activities. This study aimed to evaluate the impact of substrate selection on the enzyme inhibition activities and the levels of bioactive compounds such as cordycepin and adenosine in C. militaris, demonstrating that substrate selection markedly affects both these enzymes’ inhibition activities and bioactive compound levels. Particularly, C. militaris fruiting bodies grown on Brihaspa atrostigmella showed the highest concentrations of cordycepin (2.932 mg/g) and adenosine (1.062 mg/g). This substrate also exhibited the most potent α-glucosidase inhibition with an IC₅₀ value of 336.4 ± 16.0 µg/mL and the most effective α-amylase inhibition with an IC₅₀ value of 504.6 ± 4.2 µg/mL. Conversely, C. militaris cultivated on the solid residues of Gryllus bimaculatus displayed the strongest xanthine oxidase (XOD) inhibition, with the lowest IC₅₀ value of 415.7 ± 11.2 µg/mL. These findings highlight the critical role of substrate choice in enhancing the medicinal properties of C. militaris, suggesting that optimized cultivation can enhance the bioactive properties for more effective natural therapies for diabetes and other metabolic disorders. This study not only extends the understanding of C. militaris’ pharmacological potential but also illustrates its applicability in developing customized treatment options. Full article

We have recently shown that experience of flight remarkably enhanced subsequent terrestrial phonotaxis in females in response to the male calling song. Here, we elucidated the possible roles of octopamine and serotonin in the enhancing effect of flying on phonotactic behavior. Octopamine is known to be released into the hemolymph during flight in insects; however, the octopamine receptor antagonist epinastine did not abolish the effects of flight in our study. On the contrary, the drug significantly potentiated the influence of flying on phonotactic behavior. The octopamine receptor agonist chlordimeform, at a concentration of 2 mM, which was previously found to activate aggression in crickets, dramatically reduced the phonotactic response. However, at a 10-times-lower dose, chlordimeform produced a light but significant decrease in the time that females took to reach the source of the calling song. A similar effect was produced by octopamine itself, which hardly passes the blood–brain barrier in insects. The effect of flight was completely abolished in female crickets treated with alpha-methyl tryptophan (AMTP). AMPT suppresses the synthesis of serotonin, decreasing its content in the nervous systems of insects, including crickets. An activation of the serotonin synthesis with 5-hydroxytryptophan mimicked the effect of flight by increasing the number of visits to and the time spent in the zone near the source of the calling song. The 5-HT content in the third thoracic ganglion was significantly higher in flyers compared to the control group. In contrast, no changes in the octopamine level were observed in the third thoracic ganglion, which is known to play a crucial role in decision-making involved in intraspecific interactions. Therefore, the results suggest that although octopamine is known to be released into the hemolymph during flight, it is likely to inhibit rather than activate the central mechanisms related to phonotaxis. The weak facilitating effect of a low dose of chlordimeform can be attributed to the activation of peripheral octopaminergic receptors. Our results suggest that the serotoninergic system may contribute to the facilitation of female phonotactic behavior by flying. We suggest that both flying and serotonin enhance sexual motivation in females and, by these means, impact their behavioral response to the male calling song. Full article