Two-spotted Cricket Gryllus Bimaculatus Research Articles

Characterization and bioactive protein hydrolysates from two-spotted cricket (Gryllus bimaculatus De Geer) and short-tail cricket (Brachytrupes portentosus Lichtenstein)

Characterization and bioactive protein hydrolysates from two-spotted cricket (Gryllus bimaculatus De Geer) and short-tail cricket (Brachytrupes portentosus Lichtenstein)

Cutting-edge exploration of insect utilization in ruminant nutrition-feature and future: a systematic review and meta-analysis.

There has been a growing interest in using insects as sustainable protein sources for ruminant feed, such as the adults of the two-spotted cricket (Gryllus bimaculatus), larvae of the mealworm beetle (Tenebrio molitor), black soldier fly (Hermetia illucens), and pupae of the silkworm (Bombyx mori). The advantages of these insects over other plant materials lie in their elevated levels of crude protein and fat. However, this interest lacks a comprehensive understanding of the impact of insects on the ruminal fermentation processes, including digestibility and gas production, as well as the impact on animal performance and related health aspects. This review offers a comprehensive analysis of ruminal fermentation indices across diverse insect species. Employing descriptive and meta-analysis methodologies, we examined the impact of incorporating insect-derived meals in ruminants' diets. Moreover, we evaluated the growth performance and biochemical parameters of blood in ruminants when species such as Tenebrio molitor, Hermetia illucens, Oriental Hornet (Vespa Orientalis), and Bombyx mori were incorporated into ruminants' diets. The meta-analysis was performed on a limited dataset of 14 in vitro and eight in vivo trials, investigating insect meal as a potential feed source. A comparison is drawn between these insect-based feeds and conventional dietary sources such as soybean meal, alfalfa hay, and commercial concentrate diets. Our meta-analysis revealed that incorporating Gryllus bimaculatus and Hermetia illucens to partially replace protein sources in ruminants' diet did not adversely affect digestibility, ruminal fermentation, and ruminant production, supporting the feasibility as a feed ingredient for ruminant animals. In addition, the oriental hornet showed an overall higher outcome on the final BW, ADG, digestibility, and volatile fatty acid (VFA) production, suggesting the promising effect of this insect for future use in ruminants. The data also indicates that dietary insect inclusion levels should not exceed 30% (DM basis) to achieve an optimal ruminal fermentation profile. Furthermore, it offers comparative insights into the nutritional value of these insects, which warrant further investigation at the in vivo level. Ultimately, the existing understanding of the nutritional utilization potential of these insects by ruminants, particularly concerning macro- and micronutrients, is evaluated and revealed to be significantly constrained.

Impact of temperature on the bionomics and geographical range margins of the two-spotted field cricket Gryllus bimaculatus in the world: Implications for its mass farming.

Gryllus bimaculatus (Orthoptera: Gryllidae) is widely considered an excellent nutrient source for food and feed. Despite its economic importance, there is limited information on the impact of temperature on the bionomics of this cricket to guide its effective and sustainable mass production in its geographical range. The biological parameters of G. bimaculatus were investigated at eight different temperatures ranging from 20-40˚C. The Insect Life-Cycle Modelling (ILCYM) program was used to fit linear and non-linear functions to the data to describe the influence of temperature on life history parameters and its farmability under the current and projected climate for 2050. Our results revealed that G. bimaculatus was able to complete its lifecycle in the temperature range of 20°C to 37°C with a maximum finite rate of population increase (= 1.14) at 35°C. The developmental time of G. bimaculatus decreased with increasing temperature. The least developmental time and mortality were attained at 32°C. The highest wet length and mass of G. bimaculatus occurred at 32°C. The lowest temperature threshold for G. bimaculatus egg and nymph development was approximated using linear regression functions to be at 15.9°C and 16.2°C with a temperature constant of 108.7 and 555.6 degree days. The maximum fecundity (2301.98 eggs per female), net reproductive rate (988.42 daughters/ generation), and intrinsic rate of natural increase (0.134 days) were recorded at 32°C and the shortest doubling of 5.2 days was observed at 35°C. Based on our findings G. bimaculatus can be farmed in countries with temperatures ranging between 20 and 37°C around the globe. These findings will help the cricket farmers understand and project the cricket population dynamics around the world as influenced by temperature, and as such, will contribute to more efficient farming.

Structural Differences Between Hot Air-Dried and Freeze-Dried Two-Spotted Cricket (Gryllus bimaculatus), House Cricket (Acheta domesticus), and Silkworm (Bombyx mori) Larvae and Their Effect on Powder Properties After Grinding

Structural Differences Between Hot Air-Dried and Freeze-Dried Two-Spotted Cricket (Gryllus bimaculatus), House Cricket (Acheta domesticus), and Silkworm (Bombyx mori) Larvae and Their Effect on Powder Properties After Grinding

Identification and Expression Analysis of a cDNA Encoding Cyclophilin A from Gryllus bimaculatus (Orthoptera: Gryllidae)

Cyclophilin A (CypA), a cytosolic binding protein of cyclosporine A, is an immunosuppressive drug. In this study, CypA cDNA was cloned from the two-spotted cricket Gryllus bimaculatus (gCypA). The protein encoded by gCypA comprises 165 amino acids with a molecular mass of 19.23 kDa and an isoelectric point of 9.38 and possesses three N-glycosylation sites and 17 phosphorylation sites. The secondary and tertiary structures of gCypA were identified, and homology analysis revealed that it shares around 73%-81% sequence identities with other CypA proteins. When the researchers analyzed the expression levels of gCypA mRNA in various tissues, they found that the foregut exhibited nearly the same expression level as that of the dorsal longitudinal flight muscle (the control). However, gCypA mRNA expression in the fat body, Malpighian tubes, and midgut was less than half of that in the dorsal longitudinal flight muscle. Under endoplasmic reticulum stress conditions, gCypA mRNA expression was highest in Malpighian tubules (about two times higher than the expression in the control). Under starvation conditions, gCypA mRNA expression increased to three times that of the dorsal longitudinal flight muscle 6 days after starvation. Nonetheless, its expression levels decreased in Malpighian tubules under all starvation conditions. This study provides insights into the physiological role of gCypA in G. bimaculatus.

Segmental expression of two ecdysone pathway genes during embryogenesis of hemimetabolous insects

Signaling networks are redeployed across different developmental times and places to generate phenotypic diversity from a limited genetic toolkit. Hormone signaling networks in particular have well-studied roles in multiple developmental processes. In insects, the ecdysone pathway controls critical events in late embryogenesis and throughout post-embryonic development. While this pathway has not been shown to function in the earliest stage of embryonic development in the model insect Drosophila melanogaster, one component of the network, the nuclear receptor E75A, is necessary for proper segment generation in the milkweed bug Oncopeltus fasciatus. Published expression data from several other species suggests possible conservation of this role across hundreds of millions of years of insect evolution. Previous work also demonstrates a second nuclear receptor in the ecdysone pathway, Ftz-F1, plays a role in segmentation in multiple insect species. Here we report tightly linked expression patterns of ftz-F1 and E75A in two hemimetabolous insect species, the German cockroach Blattella germanica and the two-spotted cricket Gryllus bimaculatus. In both species, the genes are expressed segmentally in adjacent cells, but they are never co-expressed. Using parental RNAi, we show the two genes have distinct roles in early embryogenesis. E75A appears necessary for abdominal segmentation in B. germanica, while ftz-F1 is essential for proper germband formation. Our results suggest that the ecdysone network is critical for early embryogenesis in hemimetabolous insects.

Effect of astaxanthin isomer supplementation on their accumulation in edible orthopterans: migratory locusts and two-spotted crickets

The effects of an all-E-isomer-rich astaxanthin diet (E-AST-D) andZ-isomer-rich astaxanthin diet (Z-AST-D) supplementation on astaxanthin accumulation and isomer composition in the edible orthopterans, migratory locust (Locusta migratoria) and two-spotted cricket (Gryllus bimaculatus), were investigated.Z-Isomer-rich astaxanthin was prepared from the all-E-isomer via thermal treatment in corn oil at 160 °C for 30 min, increasing the totalZ-isomer ratio from 1.3 to 57.7%. Supplementation with E-AST-D and Z-AST-D toL. migratoria had little effects on astaxanthin concentration and isomer composition in the body. In contrast, astaxanthin supplementation toG. bimaculatus significantly improved the astaxanthin concentration, and when Z-AST-D was fed, the astaxanthin concentration was approximately eight times higher than that of supplementation with E-AST-D. This suggests thatL. migratoria exhibits very low astaxanthin isomer bioavailability, whereasG. bimaculatus can absorb astaxanthin isomers from its diet.L. migratoria may synthesise astaxanthin endogenously regardless of dietary astaxanthin content. TheZ-isomers were more bioavailable than the all-E-isomer inG. bimaculatus. Furthermore, astaxanthin isomer ratios in the faeces of both species were different from the dietary sources, suggesting that these ratios were modulated during digestion. These findings are important for increasing the added value of insect foods and for elucidating the mechanism of astaxanthin isomerisation in insects.

Experimental investigation of hybrid thermoelectric evaporative air-cooling system for crickets rearing process

<span lang="EN-US">Due to the effects of the change in temperature that have resulted in dramatic changes in the livelihoods of crickets. Hence, the implementation of cooling technologies is an important factor for alleviating these negative consequences. This research presents the experimentally investigate the feasibility of employing a thermoelectric cooler in combination with an evaporative air-cooling system for two-spotted cricket (Gryllus bimaculatus) rearing process. The proposed cooling system has been installed to reduce the temperature that appropriate for the cricket rearing. The experimental results show that the product air temperature of cricket rearing pens with thermoelectric evaporative air-cooling system decreases form ambient air. The average temperature of the cricket rearing pens with thermoelectric evaporative air-cooling system is 29.66 °C, with the highest temperature at 31.40 °C. While the average temperature of the cricket rearing pens without thermoelectric evaporative air-cooling system is 33.75 °C, with the highest temperature at 37.10 °C. Furthermore, this research also shows that this proposed system can improve cricket survival rate. The crickets that reared in the prototype system have a survival rate of 88.5%, while survival rate of crickets in an uncontrolled pen is 67.2%. This paper provides a potential of applying thermoelectric evaporative air-cooling for cricket farming.</span>

Effects of Substituting the Two-Spotted Cricket (Gryllus bimaculatus) Meal for Fish Meal on Growth Performances and Digestibility of Striped Snakehead (Channa striata) Juveniles.

This study aimed to investigate the potential of using field two-spotted cricket Gryllus bimaculatus as the main protein source in fish feed for striped snakehead (Channa striata) juveniles. A 10-week feeding effect on growth performance, feed utilization, digestibility of major nutrients, including amino acids, and physiological outputs of nitrogen and phosphorus were determined. A total of 225 C. striata juvenile fish (Initial weight, 15.0 ± 0.1 g) were randomly distributed into three dietary groups in triplicate (25 fish per rectangular aquarium within a semi-recirculating system). Each group was hand-fed one of the experimental diets containing the graded level of a cricket meal (CM) replacing 0%, 50%, and 100% (CM0%, CM50%, and CM100%, respectively) of fish meal (FM) protein component. The results showed that growth performance and protein retention tended to increase with increasing dietary CM levels, whereas the waste outputs of nitrogen (N) and phosphorus (P) decreased. Apparent net protein utilization (ANPU) and P retention values increased with increasing levels of cricket meal inclusion level in the diet. There was a significant reduction in both N and P solid waste and dissolved waste output for snakehead with increased CM inclusion. There were significant effects of CM level on fish whole-body composition in terms of elevated protein and fat content. In conclusion, the CM is a viable alternative protein source for aquaculture feeds and can be included up to 100% as a replacement for FM without compromising the growth performance of striped snakehead Channa striata juveniles. This may also have a more favorable impact, with the potential to reduce N and P loading to the environment.

Best Practices for Comprehensive Annotation of Neuropeptides of Gryllus bimaculatus.

Genome annotation is critically important data that can support research. Draft genome annotations cover representative genes; however, they often do not include genes that are expressed only in limited tissues and stages, or genes with low expression levels. Neuropeptides are responsible for regulation of various physiological and biological processes. A recent study disclosed the genome draft of the two-spotted cricket Gryllus bimaculatus, which was utilized to understand the intriguing physiology and biology of crickets. Thus far, only two of the nine reported neuropeptides in G. bimaculatus were annotated in the draft genome. Even though de novo assembly using transcriptomic analyses can comprehensively identify neuropeptides, this method does not follow those annotations on the genome locus. In this study, we performed the annotations based on the reference mapping, de novo transcriptome assembly, and manual curation. Consequently, we identified 41 neuropeptides out of 43 neuropeptides, which were reported in the insects. Further, 32 of the identified neuropeptides on the genomic loci in G. bimaculatus were annotated. The present annotation methods can be applicable for the neuropeptide annotation of other insects. Furthermore, the methods will help to generate useful infrastructures for studies relevant to neuropeptides.

Surrounding gas composition affects the calling song development in the two-spotted cricket (Gryllus bimaculatus).

Male crickets emit acoustic signals (i.e., songs) by chirping using their forewings. Although the mechanisms and adaptive functions of these songs are well studied, knowledge about how songs develop within a generation is relatively scarce. Our previous work demonstrated a stable peak frequency at 5.7 kHz in the calling songs recorded from mature adult male crickets (Gryllus bimaculatus). In the present study, we monitored changes in the frequency component over time from the sexual maturity stage (early adult stage). We recorded 300 calling songs from a pool of 122 adults. The peak frequency distribution was lower and unstable (i.e., greater coefficient of variance) in the early adult stage. The mean peak frequency was 4.9 kHz on day 3, but gradually converged to 5.8 kHz over the 2-week adult stage. Immature adult males (emitting immature songs) produced an appropriately tuned song with a peak frequency of 5.8 kHz in an environment of 80% helium and 20% oxygen. These results suggest that the frequency component of the calling song is acquired during the early to mid-adult stage, and may be related to sexual maturation in males. Findings from the helium substitution experiment revealed that physical resistance from surrounding gas molecules negatively affect the stability of male singing, and that muscle development and forewing hardening may contribute to the maturation of singing, suggesting that females may adaptively select sexually mature males based on song traits.

Toll signalling promotes blastema cell proliferation during cricket leg regeneration via insect macrophages.

Hemimetabolous insects, such as the two-spotted cricket Gryllus bimaculatus, can recover lost tissues, in contrast to the limited regenerative abilities of human tissues. Following cricket leg amputation, the wound surface is covered by the wound epidermis, and plasmatocytes, which are insect macrophages, accumulate in the wound region. Here, we studied the function of Toll-related molecules identified by comparative RNA sequencing during leg regeneration. Of the 11 Toll genes in the Gryllus genome, expression of Toll2-1, Toll2-2 and Toll2-5 was upregulated during regeneration. RNA interference (RNAi) of Toll, Toll2-1, Toll2-2, Toll2-3 or Toll2-4 produced regeneration defects in more than 50% of crickets. RNAi of Toll2-2 led to a decrease in the ratio of S- and M-phase cells, reduced expression of JAK/STAT signalling genes, and reduced accumulation of plasmatocytes in the blastema. Depletion of plasmatocytes in crickets using clodronate also produced regeneration defects, as well as fewer proliferating cells in the regenerating legs. Plasmatocyte depletion also downregulated the expression of Toll and JAK/STAT signalling genes in the regenerating legs. These results suggest that Spz-Toll-related signalling in plasmatocytes promotes leg regeneration through blastema cell proliferation by regulating the Upd-JAK/STAT signalling pathway.

Larval Rearing Methods for Two Endangered Species of Diving Beetle, Cybister chinensis Motschulsky, 1854 and Cybister lewisianus Sharp, 1873 (Coleoptera: Dytiscidae), Using Laboratory-Bred Food Prey

To facilitate ex-situ conservation of predaceous endangered insect species large numbers of live prey organisms are typically collected from the natural environment, potentially exacerbating biodiversity decline. To address this issue, two endangered beetle species (Cybister chinensis Motschulsky, 1854 and Cybister lewisianus Sharp, 1873) were reared using only laboratory-bred food. The beetle larvae were provided with laboratory-bred two-spotted cricket (Gryllus bimaculatus DeGeer; Orthoptera: Gryllidae) larvae as prey. The survival rates of the beetle larvae were as follows: C. chinensis, first instar larvae, 100% (n = 25), second instar larvae, 100% (n = 25), and third instar larvae, 92% (n = 23); C. lewisianus, first instar larvae 96% (n = 24), second instar larvae 92% (n = 23), and third instar larvae 92% (n = 23). The body length of adult insects fed laboratory-bred crickets did not significantly differ compared to the body length of field-collected adults.

Naturally-derived protein extract from Gryllus bimaculatus improves antioxidant properties and promotes osteogenic differentiation of hBMSCs.

Naturally-derived proteins or peptides are promising biopolymers for tissue engineering applications owing to their health-promoting activity. Herein, we extracted proteins (~90%) from two-spotted cricket (Gryllus bimaculatus) and evaluated their osteoinductive potential in human bone marrow-derived mesenchymal stem cells (hBMSCs) under in vitro conditions. The extracted protein isolate was analyzed for the amino acid composition and the mass distribution of the constituent peptide fraction. Fourier transform infrared (FTIR) spectroscopy was used to determine the presence of biologically significant functional groups. The cricket protein isolate (CPI) exhibited characteristic protein peaks in the FTIR spectrum. Notably, an enhanced cell viability was observed in the presence of the extracted proteins, showing their biocompatibility. The CPI also exhibited antioxidant properties in a concentration-dependent manner. More significant mineralization was observed in the CPI-treated cells than in the control, suggesting their osteoinductive potential. The upregulation of the osteogenic marker genes (Runx2, ALP, OCN, and BSP) in CPI treated media compared with the control supports their osteoinductive nature. Therefore, cricket-derived protein isolates could be used as functional protein isolate for tissue engineering applications, especially for bone regeneration.

The complete mitochondrial genome of the two-spotted cricket Gryllus bimaculatus (Orthoptera: Gryllidae) from South Korea

The complete mitochondrial genome of a two-spotted cricket Gryllus bimaculatus (Orthoptera: Gryllidae) from South Korea is determined and characterized in this study. The circular genome is 16,075 bp long, which consists of 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, 22 transfer RNA genes, and an A + T−rich region. It has a base composition of A (40.35%), G (9.09%), C (16.80%), and T (33.76%). The gene order is identical to the ancestral gene arrangement pattern generally shown in arthropods, with the exception of an inversion of trnN-trnS1-trnE into trnE - trnS1 - trnN . The maximum likelihood (ML) tree supports that G. bimaculatus is a distinct member of the monophyletic family Gryllidae.

CDNA Cloning and Expression Analysis of Troponin C from Gryllus bimaculatus (Orthoptera: Gryllidae)

Few reports have described the effect of starvation on insect muscle physiology and development. This study examined the role of troponin C (TnC) in the skeletal muscles and digestive tracts of the two-spotted cricket (Gryllus bimaculatus; Orthoptera: Gryllidae) during starvation and re-feeding. The TnC gene of G. bimaculatus (GrybiTnC) was cloned and found to encode a 153-amino-acid protein with a theoretical isoelectric point of 4.02 and molecular weight of 17,368.23 Da. Homology analyses revealed that GrybiTnC exhibited high amino acid similarities with TnCs from other insects, showing sequence identities ranging from ∼54 to 75%. GrybiTnC has two Ca2+-binding sites and five EF-hand motifs, similar to most TnC proteins. GrybiTnC gene expression was examined under starvation and re-feeding conditions in three different skeletal muscle and digestive tract regions. During starvation, GrybiTnC gene expression was unchanged in muscle but upregulated in the foregut and hindgut. Whereas GrybiTnC gene expression in muscle was similar under re-feeding and starvation conditions, it was upregulated in the foregut and midgut by re-feeding with carbohydrates and lipids and downregulated in the hindgut by re-feeding with carbohydrates, proteins and lipids.

Patents on Insect-based Feeds for Animals Including Companion Animals, and Terrestrial and Aquatic Livestock in Korea.

The demand for alternative protein sources by the livestock industry has increased substantially. Therefore, insects are being promoted as a novel nutrient source in animal feed. As detailed in this review, eleven patents related to feeding insects to terrestrial animals including livestock and companion animals have been commercially applied. Six and eight of the patents have been used to produce poultry and fish, and crustacean feed, respectively. The most promising species for industrial feed production was the black soldier fly (Hermetia illucens), the mealworm (Tenebrio molitor), and the two-spotted cricket (Gryllus bimaculatus). Regarding research areas of the patents reviewed here, studies on the composition and optimal mixing ratio of feeds and on insect rearing, harvesting, and post-harvest technologies were mainly performed for the industrial mass production of safe and functional animal feeds containing insects. Continuous scientific innovations and improved processing technologies will aid further advancements in this field. Therefore, this review offers insights to identify directions of future research and provides information on different insect-based feedstuffs for animals including terrestrial livestock, fish and shellfish, and companion animals, as also discussed in various patents.

(±)-Kituramides A and B, pairs of enantiomeric dopamine dimers from the two-spotted cricket Gryllus bimaculatus

Two-spotted cricket Gryllus bimaculatus is one of many cricket species, and it is widely used as a food source for insectivorous animals. Moreover, this species is one of the edible insects approved by the Korea Food and Drug Administration (KFDA). (±)-Kituramides A (1) and B (2), which are pairs of novel enantiomeric dopamine dimers possessing a formamide group, were isolated from the two-spotted cricket, together with four other known biosynthetically related compounds (3-6). The chemical structures of 1 and 2 were elucidated using a combination of 1D and 2D NMR spectroscopic experiments and HR-ESIMS data. Compounds 1 and 2 were identified as racemic mixtures; the enantiomers (+)-1/2 and (-)-1/2 were successfully separated by utilizing a chiral HPLC column. The absolute configurations of (±)-1 and (±)-2 were unambiguously delineated by the application of quantum chemical ECD calculations. Further, these insect-derived substances were evaluated to understand their effects on cytokine expression in adipocytes. Treatment with (-)-1, (+)-2, and (-)-2 during adipocyte differentiation significantly promoted the expression of Leptin and IL-6, which resembles the actions of dopamine.

Function of myosuppressin in regulating digestive function in the two-spotted cricket, Gryllus bimaculatus

Myosuppressin is one of essential peptides controlling biological processes including feeding behavior. Here we identified and characterized the cDNAs that encode myosuppressin precursor and its receptor in the two-spotted cricket Gryllus bimaculatus. The presence of the mature peptide (Grybi-MS) was confirmed by direct measurement of adult brain. RT-PCR revealed the tissue distribution of these transcripts; myosuppressin is expressed predominantly in the brain and central nervous system, whereas its receptor is ubiquitously expressed in the cricket body. To address the function of Grybi-MS, we performed several bioassays to test concerning feeding behavior and digestive function upon exposure to Grybi-MS. Administration of synthetic Grybi-MS resulted in increased feeding motivation, accompanied by an increase in food intake. Meanwhile, the hemolymph lipid and carbohydrate titers were both elevated after Grybi-MS injection. As the intestinal contraction is significantly inhibited by the exposure to Grybi-MS, the upregulating feeding index might be complicated in the cricket body. The current data indicate that Grybi-MS modulates feeding behavior to control the physiological processes in the cricket.

Immediate-Early Promoter-Driven Transgenic Reporter System for Neuroethological Research in a Hemimetabolous Insect.

Genes expressed in response to increased neuronal activity are widely used as activity markers in recent behavioral neuroscience. In the present study, we established transgenic reporter system for whole-brain activity mapping in the two-spotted cricket Gryllus bimaculatus, a hemimetabolous insect used in neuroethology and behavioral ecology. In the cricket brain, a homolog of early growth response-1 (Gryllus egr-B) was rapidly induced as an immediate-early gene (IEG) in response to neuronal hyperexcitability. The upstream genomic fragment of Gryllus egr-B contains potential binding sites for transcription factors regulated by various intracellular signaling pathways, as well as core promoter elements conserved across insect/crustacean egr-B homologs. Using the upstream genomic fragment of Gryllus egr-B, we established an IEG promoter-driven transgenic reporter system in the cricket. In the brain of transgenic crickets, the reporter gene (a nuclear-targeted destabilized EYFP) was induced in response to neuronal hyperexcitability. Inducible expression of reporter protein was detected in almost all neurons after neuronal hyperexcitability. Using our novel reporter system, we successfully detected neuronal activation evoked by feeding in the cricket brain. Our IEG promoter-driven activity reporting system allows us to visualize behaviorally relevant neural circuits at cellular resolution in the cricket brain.