Cricket Acheta Domesticus Research Articles

Assessing the potential phytosanitary threat of the house cricket Acheta domesticus

Phytosanitary threats can pose substantial risks to global agriculture and ecological systems, affecting biodiversity, human well-being, and food security. Meanwhile, global warming is projected to exacerbate these threats in the future. One in Europe already widely distributed potential phytosanitary threat that may benefit from global warming is the house cricket Acheta domesticus. This study explored the potential of A. domesticus as a relevant non-native phytosanitary threat under changing climatic conditions by conducting a series of functional response experiments across a temperature gradient (20, 25, and 30 °C). Acheta domesticus exhibited comparable patterns of seed consumption and functional responses. Seed type (millet seeds, wheat grains) and temperature increase influenced the damage inflicted on seeds, with softer and smaller seeds being more susceptible to damage, further amplified by warmer temperatures. The study's outcomes underline the phytosanitary threat that A. domesticus may pose. Considering the species' established presence and adaptable nature in urban environments exacerbates the potential for A. domesticus to transition to rural and agricultural areas. Its increasing production as a food item, paired with the here-identified potential to damage seeds, emphasizes the need for proactive and science-based strategies to address emerging phytosanitary threats driven by non-native species under changing climatic conditions. As global temperatures continue to rise, the assessment and management of potential pest species like A. domesticus will be crucial for safeguarding agriculture productivity and ecological balance.

Using AI to decode the behavioral responses of an insect to chemical stimuli: towards machine-animal computational technologies

Orthoptera are insects with excellent olfactory sense abilities due to their antennae richly equipped with receptors. This makes them interesting model organisms to be used as biosensors for environmental and agricultural monitoring. Herein, we investigated if the house cricket Acheta domesticus can be used to detect different chemical cues by examining the movements of their antennae and attempting to identify specific antennal displays associated to different chemical cues exposed (e.g., sucrose or ammonia powder). A neural network based on state-of-the-art techniques (i.e., SLEAP) for pose estimation was built to identify the proximal and distal ends of the antennae. The network was optimised via grid search, resulting in a mean Average Precision (mAP) of 83.74%. To classify the stimulus type, another network was employed to take in a series of keypoint sequences, and output the stimulus classification. To find the best one-dimensional convolutional and recurrent neural networks, a genetic algorithm-based optimisation method was used. These networks were validated with iterated K-fold validation, obtaining an average accuracy of 45.33% for the former and 44% for the latter. Notably, we published and introduced the first dataset on cricket recordings that relate this animal’s behaviour to chemical stimuli. Overall, this study proposes a novel and simple automated method that can be extended to other animals for the creation of Biohybrid Intelligent Sensing Systems (e.g., automated video-analysis of an organism’s behaviour) to be exploited in various ecological scenarios.

Venom extraction method influences venom composition and potency in the giant house spider Eratigena atrica (C. L. Koch, 1843)

Extraction is the first step when investigating venom composition and function. In small invertebrates, widely used extraction methods include electrostimulation and venom gland extraction, however, the influence of these methods on composition and toxicology is poorly understood. Using the Giant House Spider Eratigena atrica as a model, we show that electrostimulation and venom gland removal extraction methods produce different protein profiles as assessed by Coomassie-stained SDS-PAGE and significantly different potencies in the cricket Acheta domesticus.

Application of audio analysis in cultivated insect farms in Uzbekistan

Despite the merits of setting up farms to grow cultivated insects, the dramatic climate change on the planet creates some barriers to the successful maintenance of such farms and their distribution. This article discusses a method for increasing the productivity of cultivated insect farms by introducing an audio and video analysis system using artificial intelligence technologies. The prospects for the introduction of systems on farms of cultivated insects are disclosed in order to minimize the effects of adverse environmental conditions on insects, as well as to reduce production costs by minimizing the use of manual labor on the farm. The results showed that the impact of external factors on individuals of crickets Acheta Domesticus directly affects their stridulation and makes it possible to identify and timely eliminate the impact of adverse environmental conditions. It must be answered that it is critically important in the analysis of cricket stridulations to take into account such factors as: the circadian rhythm and the time of mass eating of food by crickets in the morning.

The effects of rearing density on growth, survival, and starvation resistance of the house cricket Acheta domesticus

Alternative food sources have become an important focus of research due to increased food demand coupled with reductions in traditional food productivity. In particular, substitutes for protein sources have been of increasing interest due to the unsustainability of traditional protein sources. Insects have been identified as a sustainable alternative to traditional protein sources, as they are easy to produce and contain essential proteins, fats, and minerals. However, mass-rearing insects requires similar considerations as farming traditional protein sources. To increase productively, growth and survival must be maximized at the highest possible densities while minimizing disease and food requirements. Here, we use the house cricket Acheta domesticus, a highly cultivated insect species, to investigate optimal densities for mass rearing at 14 days of age (4th instar). Nymphs were separated into density groups of 0.09, 0.19, 0.47, and 0.93 cricket/cm2 and monitored for growth and survival. Multiple regression revealed sex (p < 0.0001), density (p < 0.0001), and sex*density interaction (p = 0.0345) as predictors of growth rate. Survival to maturation was significantly reduced in both 0.47 (31%) and 0.93 (45%) cricket/cm2 groups compared to the controls. A second experiment was then conducted to investigate the starvation resistance of adult crickets reared from 14 days of age at 0.09, 0.19, 0.93, and 1.86 cricket/cm2. A second multiple regression analysis revealed only density (p < 0.0001) and to a lesser extent sex (p = 0.0005) to be predictors of starvation resistance. These results indicate that mass-rearing house crickets is most optimal at densities < 0.93 cricket/cm2, where impacts on survival and starvation are minimal. Although these results have implications for cricket mass rearing, research on other endpoints, including reproduction and the synergistic effects of other environmental factors, such as temperature and humidity, should be conducted.

Screening and identification of genes associated with flight muscle histolysis of the house cricket Acheta domesticus.

Introduction: Flight muscle histolysis, as an important survival strategy, is a widespread phenomenon in insects and facilitates adaptation to the external environment in various insect taxa. However, the regulatory mechanism underlying this phenomenon in Orthoptera remains unknown. Methods: In this study, the flight muscle histolysis in the house cricket Acheta domesticus was investigated by transcriptomics and RNA interference. Results: The results showed that flight muscle histolysis in A. domesticus was standard and peaked within 9days after eclosion of adult crickets, and there was no significant difference in the peak time or morphology of flight muscle histolysis between males and females. In addition, the differentially expressed genes between before and after flight muscle histolysis were studied, of which AdomFABP, AdomTroponin T and AdomActin were identified as candidate genes, and after injecting the dsRNA of these three candidates, only the downregulated expression of AdomFABP led to flight muscle histolysis in A. domesticus. Furthermore, the expression level of AdomFABP was compared between before and after flight muscle histolysis based on RT-qPCR. Disscussion: We speculated that AdomFABP might play a role in the degradation of flight muscle by inhibiting muscle development. Our findings laid a molecular foundation for understanding the flight muscle histolysis.

The lipidome of an omnivorous insect responds to diet composition and social environment.

Lipids are biomolecules with essential roles in metabolic processes, signaling, and cellular architecture. In this study, we investigated changes in the lipidome of the house cricket Acheta domesticus subjected to diets of different nutritional composition (i.e., protein to carbohydrate ratio) and two distinct social environments (i.e., solitary or in groups). We measured relative abundances of 811 lipid species in whole-body cricket samples using flow injection analysis coupled to tandem mass spectrometry. We assessed differences in the relative abundances of lipid species induced by diet composition and social environment in female and male A.domesticus. Additionally, we performed a functional analysis of the lipids with significant differences using a recently developed database. We found that most differences in the relative abundances of lipid species were explained by sex alone. Furthermore, the lipidome of female A.domesticus was responsive to diet composition. Females fed with the balanced diet had an even higher abundance of lipids involved in lipid storage than their counterparts fed with a protein-rich diet. Interestingly, the male cricket lipidome was not responsive to diet composition. In addition, the social environment did not induce significant changes in the lipid profile neither in female nor in male crickets.

Impact of defatting and drying methods on the overall liking and sensory profile of a cereal bar incorporating edible insect species

It is necessary to develop products with desirable sensory properties in order to increase the acceptance of insect-based products by Western consumers. In this work, the impact of defatting on the sensory properties of cereal bars with yellow mealworm (Tenebrio molitor) larvae, in addition to the impact of different drying methods and different species (T. molitor and house cricket Acheta domesticus) were assessed. A model cereal bar incorporating oats, dried and dehydrated fruits was developed as well as four additional formulations with insect flour: defatted (Soxhlet method with ethanol) mealworm (TM_D), microwave (TM_MW) or oven dried (TM_O) mealworm and oven dried cricket (AD_O). A panel of 99 consumers rated overall liking and willingness to buy (9-point scale), and profiled the bars using a Check-All-That-Apply ballot. The bars with defatted or microwaved mealworm had similar liking and willingness to eat scores in comparison with the control bar. Conversely, bars with oven-dried insects had worse evaluations and were associated with negative attributes related to odor and flavor, which were hampered by defatting or microwave-drying. This study highlights how different processing methods can be applied in order to increase the sensory liking of insect-based products and also provides information on their sensory characterization.

Small-scale breeding and harvesting of house cricket Acheta domesticus

Insectivorous animals in captivity must have access to a consistent supply of live food that is both plentiful and fresh. House crickets are a nutrient-dense source of essential amino acids, carbohydrates, fats, minerals, and water, as well as a rich source of protein. Unfortunately, because feeder crickets are not widely available commercially in India, purchasing crickets for this purpose is not yet an option. Due to the demanding maintenance needed by traditional methods, many people who try to breed crickets in a home environment fail over time. With the method described in this article, it is possible to produce large quantities of crickets affordably, consistently, and with fair ease.

Consumption of cricket (Acheta domesticus) flour decreases insulin resistance and fat accumulation in rats fed with high-fat and -fructose diet.

The consumption of cricket (Acheta domesticus, AD) has recently increased due to its high nutritional and bioactive compound contents. However, limited studies have explored the beneficial effects of AD consumption. Therefore, we aimed to evaluate the protective effect of a diet supplemented with AD flour on obesity control and its complications in an in vivo model. The chemical profiling of the AD showed an important protein content, chitin, and polyunsaturated fatty acids contents. For the in vivo study, a high-fructose and saturated fat diet (HFFD) was supplemented with AD (4% and 8%). The 8% AD supplementation reduced body weight gain (19%) and serum triglycerides (37%) in HFFD-fed rats. These benefits were related to a greater lipid excretion in feces (97%) and the partial inhibition of pancreatic lipase in vitro by the aqueous extract and the hydrolyzed proteins obtained from AD. Additionally, the 8% AD supplementation improved insulin resistance measured by the HOMA index (61%). Thus, 8% AD supplementation to HFFD-fed rats was effective in preventing obesity, dyslipidemia, and insulin resistance. PRACTICAL APPLICATIONS: Obesity is a risk factor for developing insulin resistance and dyslipidemia. Therefore, there is an increasing interest in consuming foods rich in bioactive compounds as therapeutic alternatives for managing the development of obesity and its complications. Edible insects, such as crickets, are attractive for treating obesity due to their content of protein, fiber, and polyunsaturated fatty acids. Studies have explored the effect of glycosaminoglycan (GAG)-enriched extracts from the cricket Gryllus bimaculatus against obesity. However, GAG content in crickets is low, and crickets are commonly consumed whole instead of extracts. The cricket Acheta domesticus (AD) is among the most rearing cricket species as it is easy to farm and has a better flavor. However, limited studies have explored the beneficial effects of AD consumption. This study demonstrates that AD prevents obesity and ameliorates dyslipidemia and insulin resistance. Therefore, AD is a valuable entomotherapeutic strategy to reduce the comorbidities associated with diet-induced obesity.

Viral infection changes the expression of personality traits in an insect species reared for consumption

Disease-induced personality change results from endogenous and adaptive host responses or parasitic manipulation. Within animal husbandry systems understanding the connection between behaviour and disease is important for health monitoring and for designing systems considerate to animal welfare. However, understanding these relationships within insect mass-rearing systems is still in its infancy. We used a simple repeated behavioural-emergence test to examine parasite-induced differences in group personality traits in the house cricket Acheta domesticus, by comparing the behaviours of 37 individuals infected with the Acheta domesticus densovirus (AdDV) and 50 virus-free individuals. AdDV-infected animals had a much lower emergence probability, longer times until emergence, and did not change their behaviour with experience compared to the virus-free animals. AdDV-infected animals also had lower variation in their probability of emergence within the population, most likely related to animals displaying a relatively uniform sickness response. These infected animals also had higher variation in their response to experimental trial experience; this greater variation resulted from a difference between males and females. Infected females responded to experience in a similar way as virus-free animals, while AdDV-infected males showed a response to experience in the opposite direction: i.e., while all other groups reduced emergence time with experience, infected males always increased their mean emergence time as trials progressed. Our results are important not only in the context of animal personality research, but also with regards to creating husbandry systems and disease monitoring within the insects-as-food industry that are considerate to both production traits and animal welfare.

Impact of some local organic by-products on Acheta domesticus growth and meal production

The house cricket Acheta domesticus is one of the species of major interest as alternative protein source for humans in the recent research of sustainable and nutritious sources of food. However, grain feeds, feed for poultry and soybean still represent common source of feeds for the insect industry. The aim of this study was to evaluate the influence of some agro-food by-products on the growth parameters of the crickets and the nutritional composition of the final cricket meal. Our study included five by-products (maize grain distiller, fruits and vegetables, grape marc, and two brewery’s wastes), while hen feed was used as a control diet. Substrates were analysed for their microbiological contamination prior to be provided to crickets. No Listeria and Salmonella were detected, but high microbial counts were observed. Crickets grown on the given by-products showed significant differences on the insect’s weight starting from the third week. High mortality was observed on all substrates, except on maize distiller and the control diet. The final cricket meal showed a similar protein content (66-68% as is), while the lipid content was higher in the meal from cricket reared on maize distiller (22% as is). Finally, microbiological and chemical analyses on the cricket meals did not show safety concerns for the consumers. The by-products studied, except maize grain distiller, did not support an optimal cricket rearing, but more studies are necessary to identify a mix-formulation meeting the cricket nutritional requirements.

The effects of high-monosaccharide diets on development and biochemical composition of white-eyed mutant strain of house cricket (Acheta domesticus)

Tryptophan (TRP) is one of the essential amino acids in the animal body. Its exogenicity and low concentrations mean that it can be regarded as one of the key regulatory molecules at the cellular as well as physiological level. It has been shown to have a number of essential functions, such as in the production of other biologically active molecules. The main objective of this project was to investigate the effects of a high monosaccharide diet (HMD) on a hemimetabolic insect—house cricket (Acheta domesticus) and a mutant strain with impaired visual pigment synthesis (closely related to the tryptophan and kynurenine (KYN) metabolic pathway)—white eye. This study was aimed at determining the effects of glucose and fructose on cricket development and biochemical composition. A parallel goal was to compare the response of both cricket strains to HMD. ELISA assays indicated dysfunction of the TRP-KYN pathway in white strain insects and an elevated KYN/TRP ratio. Biochemical analyses demonstrated the effects of HMD mainly on fat and glycogen content. A decrease in food intake was also observed in the groups on HMD. However, no changes in imago body weight and water content were observed. The results of the study indicate a stronger response of the white strain to HMD compared to the wild-type strain. At the same time, a stronger detrimental effect of fructose than of glucose was apparent. Sex was found to be a modulating factor in the response to HMD.

231 Applications of Insect-derived Ingredients in Animal Diets

Abstract Insects have applications in many animal feeding programs for several reasons. First, increased emphasis on sustainable ingredients supports the use of insect-derived ingredients since insects have the capacity to sustainably re-purpose waste streams from food and feed production into nutrient dense ingredients. Second, many animals would naturally consume insects, thus incorporation into feeding programs may enhance animal welfare. Third, nutrient composition and availability is generally very high for insect-derived ingredients relative to requirements and formulae needs, although this varies with insect species, stage of development, feedstock on which they are raised and processing method. In addition to the essential nutrients that can be provided by feeding insect-derived ingredients, components including chitin and proteins and fatty acids with anti-microbial activity provide additional application in animal feeding programs. These concepts will be discussed relative to current knowledge about the primary insect species being reared at commercial scale: house crickets (Acheta domesticus), yellow mealworms (Tenebrio molitor), and black soldier fly larvae (Hermetia illucens).

Entomomonas asaccharolytica sp. nov., isolated from Acheta domesticus.

Strain F2AT, isolated from the cricket Acheta domesticus, was subjected to a polyphasic taxonomic characterization. Cells of the strain were rod-shaped, Gram-stain-negative and catalase- and oxidase-positive. It did not assimilate any carbohydrates. The strain's 16S rRNA gene sequence showed highest similarity to Entomomonas moraniae QZS01T (96.4 %). The next highest similarity values were found to representatives of related genera (<93 %). The genome size of strain F2AT was 3.2 Mbp and the G+C content was 36.4 mol%. Average nucleotide identity values based on blast and MUMmer and average amino acid identity values between strain F2AT and E. moraniae QZS01T were 74.29/74.43, 83.88 and 74.70 %, respectively. The quinone system predominantly contained ubiquinone Q-8. In the polar lipid profile, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unidentified phospholipid were detected. The polyamine pattern consisted of the major compounds putrescine and spermidine. Major fatty acids were C18 : 1 ω7c and C16 : 0 and the hydroxyl acids were C12 : 0 3-OH, C14 : 0 2-OH and C14 : 0 3-OH. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. Due to its association with the only species of the genus Entomomonas but its distinctness from E. moraniae we here propose the novel species Entomomonas asaccharolytica sp. nov. F2AT (=CCM 9136T=LMG 32211T).

New insights into the flavoring potential of cricket (Acheta domesticus) and mealworm (Tenebrio molitor) protein hydrolysates and their Maillard products

Insect proteins have an earthy-like flavor and have not shown great flavor potential for food applications so far. In this study, insect proteins of cricket Acheta domesticus and mealworm Tenebrio molitor larvae were first enzymatically hydrolyzed using two peptidase preparations (Flavourzyme1000L and ProteaseA “Amano”2SD). Xylose was then added to facilitate Maillard reactions (30 min, T = 98 °C, 1% (w/v) xylose). A comprehensive sensory evaluation showed that both the hydrolysis and the Maillard reactions changed the flavor description of the samples significantly to more complex and savory-like taste profiles (27 descriptors for cricket and 39 descriptors for mealworm protein). In addition, 38 odor-active molecules were identified using gas chromatography–olfactometry (1 alcohol, 5 acids, 11 aldehydes, 5 ketones and 16 heterocyclic compounds). The results showed impressively that the flavoring potential of insect proteins was significantly enhanced with respective processing.

A multifactorial proteomics approach to sex‐specific effects of diet composition and social environment in an omnivorous insect

AbstractRearing conditions may elicit noticeable plastic responses in life‐history traits of living organisms. Diet composition and the social environment have proven to influence prominent traits such as survival, body size, fecundity, and life span. Nevertheless, the physiological mechanisms underlying such responses are largely unknown. In this study, we investigated changes in the proteome of the house cricketAcheta domesticussubjected to diets of different nutritional composition (i.e., protein to carbohydrates ratio) and two distinct social environments (i.e., solitary or in groups). We measured the relative abundances of 685 proteins identified in whole‐body cricket samples using high‐performance liquid chromatography coupled to tandem mass spectrometry. Differential expression of proteins induced by diet composition and social environment in female and maleA. domesticuswas assessed in a data‐independent proteomics approach. Additionally, we performed a functional analysis of the differentially expressed proteins using comprehensive databases (KEGG and GO). We found that sex alone explained a significant portion (40.87%) of the relative protein abundance variation. Males had a higher representation of proteins involved in metabolic pathways and locomotion. In contrast, females exhibited a higher abundance of proteins related to genetic processes regulation and nutrient catabolism. Moreover, diet composition and social environment induced sex‐specific changes in a smaller set of proteins with particular roles. Females had their protein profile affected by diet composition and social environment. The involved proteins were mainly related to several protein synthesis stages, carbohydrate metabolism, and muscle development. In contrast, males were only affected by diet composition, overexpressing proteins related to hormone production, carbohydrate metabolism, and apparently depositing excess protein in the cuticle when fed with a protein‐rich diet. Evidently, diet had a more substantial influence on the proteome of the cricketA. domesticusthan the social environment, showing that diet composition may exert profound physiological changes in insects in a sex‐specific manner.

Allergenicity assessment of the edible cricket Acheta domesticus in terms of thermal and gastrointestinal processing and IgE cross-reactivity with shrimp

The allergenic potency of the cricket Acheta domesticus, a promising edible insect, has never been assessed. This work aims to study the immunoreactivity of Acheta domesticus, and its cross-reactivity with the shrimp Litopenaeus vannamei, assessing the effect of cooking and gastrointestinal digestion on their allergenic properties. Different cricket proteins were detected by immunoblotting with shrimp-allergic patients' sera. Tropomyosin was identified as the most relevant IgE-binding protein, and its cross-reactivity with shrimp tropomyosin was demonstrated by ELISA. While shrimp tropomyosin showed scarce stability to gastric digestion, cricket tropomyosin withstood the whole digestion process. The sarcoplasmic calcium-binding protein, specifically detected in shrimp, showed exceptional stability to gastrointestinal digestion. IgE-binding proteins in a model of enriched baked products were partially protected from proteolysis. In conclusion, the ingestion of A. domesticus proteins poses serious concerns to the Crustacean-allergic population. The high stability of tropomyosin may represent a risk of primary sensitization and clinical cross-reactivity.

Virus Prospecting in Crickets—Discovery and Strain Divergence of a Novel Iflavirus in Wild and Cultivated Acheta domesticus

Orthopteran insects have high reproductive rates leading to boom-bust population dynamics with high local densities that are ideal for short, episodic disease epidemics. Viruses are particularly well suited for such host population dynamics, due to their supreme ability to adapt to changing transmission criteria. However, very little is known about the viruses of Orthopteran insects. Since Orthopterans are increasingly reared commercially, for animal feed and human consumption, there is a risk that viruses naturally associated with these insects can adapt to commercial rearing conditions, and cause disease. We therefore explored the virome of the house cricket Acheta domesticus, which is both part of the natural Swedish landscape and reared commercially for the pet feed market. Only 1% of the faecal RNA and DNA from wild-caught A. domesticus consisted of viruses. These included both known and novel viruses associated with crickets/insects, their bacterial-fungal microbiome, or their plant food. Relatively abundant among these viral Operational Taxonomic Units (OTUs) was a novel Iflavirus, tentatively named Acheta domesticus Iflavirus (AdIV). Quantitative analyses showed that AdIV was also abundant in frass and insect samples from commercially reared crickets. Interestingly, the wild and commercial AdIV strains had short, extremely divergent variation hotspots throughout the genome, which may indicate specific adaptation to their hosts’ distinct rearing environments.

MEDI: Macronutrient Extraction and Determination from invertebrates, a rapid, cheap and streamlined protocol.

Macronutrients, comprising carbohydrates, proteins and lipids, underpin many ecological processes, but their quantification in ecological studies is often inaccurate and laborious, requiring large investments of time and bulk samples, which make individual‐level studies impossible. This study presents Macronutrient Extraction and Determination from Invertebrates (MEDI), a protocol for the direct, rapid and relatively low‐cost determination of macronutrient content from single small macroinvertebrates.Macronutrients were extracted by a sequential process of soaking in 1:12 chloroform:methanol solution to remove lipid and then solubilising tissue in 0.1 M NaOH. Proteins, carbohydrates and lipids were determined by colorimetric assays from the same individual specimens.The limits of detection of MEDI with the equipment and conditions used were 0.067, 0.065 and 0.006 mg/ml for proteins, carbohydrates and lipids respectively. Adjusting the volume of reagents used for extraction and determination can broaden the range of concentrations that can be detected. MEDI successfully identified taxonomic differences in macronutrient content between five insect species.Macronutrient Extraction and Determination from Invertebrates can directly and rapidly determine macronutrient content in tiny (dry mass ~3 mg) and much larger individual invertebrates. Using MEDI, the total macronutrient content of over 50 macroinvertebrates can be determined within around 3 days of collection at a cost of ~$1.35 per sample.