Tettigoniidae Research Articles

A review of the Use of Acoustic Organs in Insects in Terms of Predatory Behaviors

Acoustic organs, generally involved in sound generation and hearing, play a crucial role in insects, particularly in communication and mating behaviors. However, although rare, they also contribute to predatory behaviors. Some well-known examples include parasitism in various parasitic flies like Emblemasoma sp., aggressive mimicry in bush crickets (Chlorobalius leucoviridis), which imitate the female cicadas response song, and the use of stridulation by myrmecophilous social parasites like butterflies (Maculinea sp.) and beetles (Paussus sp.) to infiltrate ant nests. Despite the significance of these behaviors, research in this area is limited due to barriers such as lack of facilities and difficulties in collecting samples. Consequently, few studies have been conducted on acoustic behaviors in predatory contexts compared to other major uses like mating. This article will review several general studies on these three aspects, summarizing the methods and findings. The studies indicate that playback experiments and observations play a crucial role, that these behaviors are highly specialized for survival, and that challenges such as limited sample collections remain

Inferring long‐distance movements of insects using combined hydrogen isotope and genetic analyses: A case study of the African edible bush‐cricket

Abstract The degree to which individuals within populations vary in whether, how far and what direction they disperse is central in order to understand many foundational questions in ecological entomology, including factors determining population and invasion dynamics, species' ability to respond to climate change or when designing conservation strategies for threatened species. This study combined stable hydrogen isotope analysis of nymphal and adult wing chitin with population genetic analysis of the cytochrome c oxidase subunit I (COI) gene to understand long‐distance movements of African edible bush cricket (Ruspolia differens) in East Africa. Results revealed that at most 77% of non‐swarming adults and 85% swarming adults originated locally, that is, within a range of a few hundred kilometres. In contrast, non‐local adults captured in Uganda likely originated from Ethiopia, Kenya or South Sudan based on the H isotopic evidence. Genetic analysis revealed 150 COI haplotypes with no significant differentiation among geographic source regions and no evidence of genetic isolation by movement distance. The observed frequent long‐distance movements, together with the historical records, which indicate that the swarm movements can be irregular in their direction, suggest that the movements represent nomadism rather than regular long‐distance migration. Our results thus provide a valuable case study of what characterizes nomadic movements in insects, which have been one of the outstanding open questions in movement ecology of animals.

Opportunities, challenges and policy gaps for sustainable consumption of edible long-horned grasshopper, Ruspolia differens, in Uganda: a review

Opportunities, challenges and policy gaps for sustainable consumption of edible long-horned grasshopper, Ruspolia differens, in Uganda: a review

Bio-ecology of the bush cricket Tarbinskiellus portentosus (Lichtenstein, 1796) (Insecta: Orthoptera: Gryllidae): a relished edible insect in Nagaland, India

Tarbinskiellus portentosus (Lichtenstein, 1796) (bush cricket), also called “viituo” in the Angami dialect, belongs to the order Orthoptera and the family Gryllidae. It is one of the most common edible insects found in Nagaland and is a potential source of animal protein and other nutrients. Despite being highly preferred as food and relished, studying their ecology, biology, and market potential is nonexistent, at least in Nagaland, India. Therefore, the present study was conducted to fill the knowledge gap on the biology and market potential of T. portentosus. Insects were collected from the wild and reared as stock at 20–25 °C. The results show that T. portentous undergoes seven nymphal instars to fully develop into an adult with an average growth rate of 9.94 ± 2.43 mg/day. T. portentosus is found in the grassland vegetation in burrows up to 800 mm depth. Adult males weigh about 2940 ± 93.0 mg, and females weigh 2980 ± 200 mg. The incubation period of eggs was 33.8 ± 0.96 days and showed a moderate percent of hatching efficiency (45.20 ± 0.28). In laboratory conditions, this cricket completed its life cycle in 341 ± 4.29 days. Collection of adults involves handpicking and pouring water, cleaning involves a gut removal process through head pulling, and preparation for consumption is done by cooking with local spices, fried or roasted. T. portentosus are sold in the local market at INR 300/- for 250–300 g. With scanty information on growth and reproduction, the present study serves as a baseline for future studies on the biology of T. portentosus that may uplift the local market through mass rearing.

Vendors' handling practices of edible long-horned grasshoppers (Ruspolia differens) products and implications on microbial safety.

Edible grasshopper, Ruspolia ruspolia, has nutritional and cherished cultural and economic importance to people from diverse cultures, particularly in over 20 African countries. It is consumed at home or commercially traded as sautéed, deep-fried, or boiled products. However, there is limited information on the hygiene practices of the vendors and the implications on the microbial safety of the final product. This research aimed at assessing the food safety knowledge, handling practices and shelf life of edible long-horned grasshopper products among vendors and the microbial safety of ready-to-eat products sold in 12 different markets in Uganda. Samples of raw, deep-fried and boiled grasshoppers were randomly collected from 74 vendors (62% street and 38% market vendors) and subjected to microbial analysis. Over 85% of the vendors surveyed had no public health food handler's certificate and >95% had limited post-harvest handling knowledge. Total aerobic bacteria (7.30-10.49 Log10 cfu/g), Enterobacteriaceae (5.53-8.56 Log10 cfu/g), yeasts and molds (4.96-6.01 Log10 cfu/g) total counts were significantly high and above the acceptable Codex Alimentarius Commission and Food Safety Authority of Ireland (FSAI) limits for ready-to-eat food products. Eight key pathogenic bacteria responsible for foodborne diseases were detected and these isolates were characterized as Bacillus cereus, Hafnia alvei, Serratia marcescens, Staphylococcus aureus, S. xylosus, S. scuiri, S. haemolyticus, and Pseudomonas aeruginosa. Findings from this study highlight the urgent need to create local and national food safety policies for the edible grasshopper "nsenene" subsector to regulate and guide street and market vending along the value chain, to prevent the transmission of foodborne diseases to consumers.

Ecology and abundance of a relict population of the bush cricket Saga pedo in the Northern Apennines, Italy.

The expansion of forest cover and intensification of agriculture represent the main threats to the bush cricket Saga pedo, currently listed as Vulnerable globally by the IUCN and included in Annex IV of the European Union Habitats Directive. Gathering information on its ecology and population size is challenging due to its low abundance and localized distribution. Additionally, the elusive and cryptic behavior of this species reduces the likelihood of its detection, potentially resulting in population underestimations. Thus, in this study, we aimed to (1) estimate S. pedo population size in relation to environmental variables and prey availability and (2) predict abundance of S. pedo in our study area for future monitoring in nearby territories. We found that the population of S. pedo in our study area consists of 197 (±115) individuals with a detection probability of 21.01% (±11.09). Detection probability of S. pedo further decreases on windy days. Moreover, we found that the investigated population of S. pedo occupies suboptimal areas, as highlighted not only by the predicted abundances but also by the association between S. pedo and other subfamilies of orthoptera that are ecologically very distant from our target species and mostly linked to mesophilic biotopes. Most of the individuals we observed are concentrated in small clearings completely within wooded matrices and therefore isolated from each other. Based on our results, it is possible that forest expansion toward open meadows represents the main threat to this population, transforming the clearings and xeric meadows (to which S. pedo is linked) into small and fragmented patches that are suboptimal and insufficient to host viable populations.

New for Russia bush crickets (Orthoptera: Tettigoniidae) from Crimea and Caucasus

Three species of bush crickets, Conocephalus conocephalus (Linnaeus, 1767), Incertana incerta (Brunner von Wattenwyl, 1882), and Parapholidoptera georgiae Massa, Buzzetti et Fontana, 2009, are recorded from Russia for the first time.

Microgeographic speciation in a complex of Anatolian bush crickets facilitated by fast evolution of reproductive isolation.

Identifying the drivers of microgeographic speciation (i.e., speciation over small, local geographic scales) is key to understand the origin of speciose groups. Here, we use genomic data to infer the demographic processes underlying diversification in Poecilimon luschani (Orthoptera: Tettigoniidae), a species complex belonging to the most diverse genus of bush crickets from the Mediterranean region (>170 taxa) that comprises three recognized subspecies with small allopatric distributions in the topographically complex Teke Peninsula, southwestern Anatolia. Phylogenomic reconstructions that include all other taxa within the species group confirmed that subspecies of P. luschani originated from a common ancestor during the Pleistocene, supporting recent (<1 Ma) diversification within a small geographical area (ca. 120 × 80 km). Genetic clustering analyses corroborated the distinctiveness of each subspecies and the cohesiveness of their respective populations, with abrupt genetic discontinuities coinciding with contemporary range boundaries. Indeed, our analyses uncovered the presence of two sympatric cryptic sister lineages that diverged <300 ka ago and do not admix despite being co-distributed. Collectively, these results support that all lineages within the complex represent independently evolving entities corresponding to full-fledged species. Statistical evaluation of alternative models of speciation strongly supports a scenario of divergence in isolation followed by a period of limited gene flow during the last glacial period, when all lineages experienced marked expansions according to demographic reconstructions. Our study exemplifies how localized allopatric divergence and fast evolution of reproductive isolation can promote microgeographic speciation and explain the high rates of endemism characterizing biodiversity hotspots.

Understudied regions and messy taxonomy: Geography, not taxonomy, is the best predictor for genetic divergence of the Poecilimon bosphoricus species group

AbstractThe complex and dynamic history of the Anatolian Peninsula during the Pleistocene set the stage for species diversification. However, the evolutionary history of biodiversity in the region is shrouded by the challenges of studying species divergence in the recent, dynamic past. Here, we study the Poecilimon bosphoricus (PB) species group to understand how the bush crickets' diversification and the regions' complex history are coupled. Specifically, using sequences of two mitochondrial and two nuclear gene segments from over 500 individuals for a comprehensive set of taxa with extensive geographic sampling, we infer the phylogenetic and geographic setting of species divergence. In addition, we use the molecular data to examine hypothesized species boundaries that were defined morphologically. Our analyses of the timing of divergence confirm the recent origin of the PB complex, indicating its diversification coincided with the dynamic geology and climate of the Pleistocene. Moreover, the geography of divergence suggests a history of fragmentation followed by admixture of populations, suggestive of a ring species. However, the evolutionary history based on genetic divergence conflicts with morphologically defined species boundaries raising the prospects that incipient species divergences may be relatively ephemeral. As such, the morphological differences observed in the PB complex may not to be sufficient to have prevented homogenizing gene flow in the past. Alternatively, with the recent origin of the complex, the lack of time for lineage sorting may underlie the discord between morphological species boundaries and genetic differentiation. Under either hypothesis, geography—not taxonomy—is the best predictor of genetic divergence.

Identification and virulence screening of fungal and bacterial entomophathogens of the edible long-horned grasshopper Ruspolia differens (Orthoptera: Tettigoniidae) from Uganda

Natural enemies are major challenges in laboratory rearing of grasshoppers, but the identity and virulence of these towards the edible long-horned grasshopper Ruspolia differens (Serville) is scarcely known. In this study, fungi and bacteria were isolated from R. differens collected from Mbarara, Masaka, Hoima, Kampala and Kabale districts in Uganda in 2018, cultured on standard microbial media, identified using molecular techniques and screened for virulence against the insect in laboratory bioassays. Fourteen and nine species of fungi and bacteria were isolated from R. differens, respectively, with the number of isolates varying based on collection site. The most prevalent entomopathogenic fungal species were Aspergillus flavus Link (27.3%), Fusarium equiseti (Corda) (24.2%), Mucor fragilis Fresen (12.1%), Clonostachys rosea (Link) (6.0%) and Aspergillus tamarii Kita (6.0%); whereas the most prevalent bacterial isolates were Serratia marcescens Bizio (38.1%), Bacillus thuringiensis (Berliner) (14.3%) and Enterobacter cloacae (Jordan) (14.3%). Nine of the fungal species namely Clavispora lusitaniae Rodrigues de Miranda, Lichtheimia corymbifera (Cohn), Trichoderma koningii Oudem, F. equiseti, M. fragilis, Aspergillus niger van Tieghem, Epicoccum sorghinum (Saccardo), C. rosea, Penicillium commune Charles Thom; and five bacterial species (Proteus penneri Hickman, S. marcescens, B. thuringiensis, Staphylococcus sciuri Kloos and Enterococcus faecalis (Andrewes and Horder)) were ~5–7-fold and ~4–5-fold, more lethal to third instars of R. differens than untreated controls, respectively. This study is the first to report C. lusitaniae, Exserohilum mcginnis Padhye and Ajello, E. sorghinum, P. penneri and E. cloacae as insect pathogens. The results suggest a need to quarantine field collected R. differens before introducing them into the insectary, as well as performing antimicrobial practices during rearing of the insect to prevent entomopathogen-based mortality.

Nanofiber embedded bioinspired strong wet friction surface.

Robust and reversible wet attachments are important for medical engineering and wearable electronics. Although ultrastrong capillarity from interfacial nano-thick liquid bridges creates tree frog's strong wet friction, its unstable nano-liquid characteristic challenges further wet friction enhancement. Here, unique hierarchical micro-nano fibrous pillars have been discovered on Chinese bush crickets exhibiting a robust wet friction ~3.8 times higher than tree frog's bulk pillar. By introducing a nano-fibrous pillar array covered with thin films (NFPF), the pillar's separation position switches from the rear to front side compared with bulk pillars, indicating the interfacial contact stress shifting from compressing to stretching. This largely decreases the interfacial separation stress to form more stable and larger nano-liquid bridges. The NFPF array with self-splitting of interfacial liquid and contact stress further guards such interfacial stress shifting to ensure a ~1.9 times friction enhancement. Last, the theories are established, and the applications on wearable electronics are validated.

Shelf life of the preheated and ready-to-eat long-horned grasshopper Ruspolia differens Serville

Abstract Ruspolia differens is an edible insect delicacy in sub-Saharan Africa, majorly harvested from the wild, with a very short shelf life (24 hours depending on the handling conditions). Combinations of preheating, roasting and drying, and storage at refrigerated and room temperature were used to prolong its shelf life. Product quality was evaluated using sensory, microbial and chemical analyses. To allow transportation from the harvesting areas to the market, preservation up to 9 hours at room temperature was possible using only preheating (boiling at 100 °C for 6 minutes). Combinations of preheating and roasting (for 25 and 35 minutes at 165 °C) resulted in moisture contents of 21.3 and 10.4% with shelf life at refrigeration temperature of 25 and 54 days, respectively. Aroma was the main factor determining the shelf life. Further drying of preheated and roasted grasshoppers resulted in a product with 4.5% moisture. In combination with vacuum packaging, storage at room temperature was possible for at least 20 weeks. This research therefore contributes to long term storage of the surplus harvested R. differens, and thus to increased food security.

Farmland biodiversity benefits from small woody features

Farmland biodiversity benefits from small woody features

Nontarget catches of traps with chemical lures may refer to the flower‐visitation, probable pollination, and feeding of bush crickets (Ensifera: Tettigoniidae)

AbstractThe diurnal bees, lepidopterans, and other pollinators are among the most studied flower‐visiting insect taxa. They mostly play distinct functions in temperate grasslands and ecotones of grassland‐forest mosaics (such as in forest steppes). Although orthopterans are widely distributed in these habitats, however, their flower visitation is nearly unknown, especially in the temperate zone. During the development of traps with chemical lures to catch Lepidoptera pests, large numbers of Orthoptera were caught that provide a chance for studying the flower visitation and odor and indirectly the host plant preference of seven temperate zone Tettigoniidae species. Data on the attractivity of isoamyl alcohol‐based semisynthetic lures for Meconema thalassinum and efficiency of phenylacetaldehyde‐based lures on Leptophyes albovittata and Phaneroptera falcata were reported for the first time. Additionally, analysis of nature photos collected from internet sources, as part of a passive citizen science also supports the revealed preference of these species. Based on photos, the studied orthopterans mainly visit Asteraceae species including the most preferred Tanacetum vulgare, Pulicaria dysenterica, Achillea millefolium, Solidago canadensis, and Centaurea scabiosa. Based on catches of volatile traps, the first data were recorded on the attractivity of phenylacetaldehyde‐ and isoamyl alcohol‐based lures on three temperate zone Orthoptera species. Results of a passive citizen science study strengthen these results that may increase the knowledge on the host plant and habitat preference of Orthoptera species.

Can protected areas and habitats preserve the vulnerable predatory bush cricket Saga pedo?

Inconspicuous species challenge conservationists when it comes to delineate long-term conservation planning or assess their status, particularly when their actual distribution is poorly known. Invertebrates in particular feature among the less represented taxa in conservation assessments. Here we follow a multidisciplinary approach for assessing the conservation coverage and address future management of the threatened orthopteran Saga pedo across Europe, shedding light on its ecological preferences and associations with protected habitats at continental and regional scales. When assessing coverage by Natura2000 and Nationally Protected Areas, we found that ca. 30% of the known populations of the species are currently not protected across Europe. However, this value is likely to be an underestimate as our species distribution models showed that ca. 70% of the potential range is not protected. At regional scale, we disclose that the species is more likely to occur in legally protected dry grassland habitat types than in non-protected grassland, yet not all protected habitats seem to represent an effective tool for the species’ conservation.Implications for insect conservationTaken together, our results provide an effective framework for addressing knowledge gaps and evaluate the conservation coverage not only of our target species, but more in general of poorly investigated species, at the same time pointing at the urgent need of transnational, coordinated, and increased efforts in monitoring and conserving insects, particularly in the case of threatened species.

Cannibalism among adult bush crickets (Ruspolia differens) when fed on different insect preys and artificial diets

Edible bush cricketsRuspolia differens have received considerable interest in recent years primarily due to their widespread consumption across Sub Sahara Africa. Currently, these pseudo grasshoppers are only available in large quantities twice a year during the rainy seasons. Therefore, there is great research interest in studying their farming potential for possible mass rearing. However, due to their cannibalistic behaviours, such attempts have proven an uphill task. This study evaluated measures that may reduce cannibalism by providing alternative prey to rearedR. differens. Ten young adults of either females or malesR. differens were kept separately in well-aerated cages (50×50×50 cm). Then, two sets of experiment were set up as follows: in the no-choice set-up, twenty live or dead second instar (L2) larvae each ofHermetia illucens,Chilo partellus,Bactrocera invadens, andSchistocerca gregaria were administered separately to both male and female cages for six successive days. In the choice set-up, a mixture of twenty live or dead L2 larvae of the insects mentioned above was fed for twelve consecutive days. The control diets included an artificial diet only or artificial diet + corn leaves and were provided for six days consecutively to both males and females separately. In each case, the proportion of cannibalism and the possibility of hunting behaviour byR. differens was recorded. Cannibalism was significantly reduced in both male and femaleR. differens cages where prey was administered compared to the control diets. Besides, cannibalism was significantly reduced in both male and femaleR. differens cages when live insect prey was provided compared to dead insect prey. There were indications of a hunting behaviour exhibited byR. differens as they tended to feed more on living than on dead insect prey. Our findings show that the addition of live insect prey could reduce the prevalence of cannibalism duringR. differens, thus preventing colony collapse due to cannibalism and also providing a safe means to eliminate insect pests, which could serve as prey.

Nutritional profile of a novel artificial diet and the effect of photoperiod on the fitness parameters of rearedRuspolia differens

The tettigoniid,Ruspolia differens, is a widely consumed grasshopper across Sub Sahara Africa (SSA), mainly where periodic large swarms occur during the rainy months. The present wild harvesting of this grasshopper species is not sustainable and limits the yearlong presence of these delicacies. One method to circumvent this is developing mass-rearing technologies for this nocturnal and omnivorous insect within SSA. However, to mass-rear this species on a large scale, the optimal diets and light regimes need to be established. Complete nutritional profiles of edible insect diets are rare. In our study, using a newly formulated artificial diet we assessed multiple performance traits forR. differens reared at two light regimes. A complete dark (&lt;1 h light, 5:95 L:D) and 50% light (~12 h light, 50:50 L:D) from newly hatched nymphs to death of the adults. Proximate composition of this novel artificial diet was carbohydrates: 53.5%, crude protein: 21.0%, ash: 7.0%, fat: 5.0%, crude fibre: 4.5%. All essential amino acids and mineral elements were also present. It took on average 8-9 moults to reach adults in the light-reared insects as opposed to 6-7 moults for those reared in the dark. Adult longevity in the dark-reared insects was also significantly longer (37±3.7 days) compared to the light-reared ones (10±3 days). These findings strongly support the nocturnal behaviour of these bush crickets and suggest rearing them in a predominantly dark environment would seem a profitable venture, as fewer energy demands in terms of lighting are required. Such a diet, when fully optimised will facilitate automation and reduce labour for feeding them in mass-rearing programs.

Dinarippiger gen. nov. (Tettigoniidae: Bradyporinae: Ephippigerini), a new saddle bush-cricket genus for Ephippiger discoidalis Fieber, 1853 from the Dinaric karst.

A new genus of the tribe Ephippigerini, Dinarippiger Skejo, Kasalo, Fontana et Tvrtković gen. nov., is described based on the characters of occiput coloration, tegmina coloration, cerci and pronotum shape. The new genus is morphologically intermediate between the genera Ephippiger Berthold, 1827 and Uromenus Bolívar, 1878, and presently includes only Dalmatian Saddle Bush Cricket, Dinarippiger discoidalis (Fieber, 1853) comb. nov., hitherto known as Ephippiger discoidalis Fieber, 1853. The species inhabits NE Italy (mainly Carso Triestino), SW Slovenia, Croatia, Bosnia & Herzegovina, and Montenegro, i.e., islands and karst habitats along the eastern Adriatic coast, with isolated findings in Albania and Italy. Its prominent variation in size and coloration has already produced many synonyms (= limbata Fischer, 1853, = limbata var. major Krauss, 1879, = limbata var. minor Krauss, 1879, = selenophora Fieber, 1853, = sphacophila Krauss, 1879), which may suggest that what is currently regarded as a single species could represent a complex of distinct species with restricted distributions. This study also presents an annotated distribution map and a bioacoustic analysis of D. discoidalis comb. nov. Further research, especially adopting molecular methods, is necessary to assess possible cryptic diversity within the genus Dinarippiger gen. nov. and elucidate its evolutionary history.

Variability in nutrient composition of the edible long-horned grasshopper (Ruspolia differens) in Uganda and its potential in alleviating food insecurity.

Ruspolia differens Serville (Orthoptera: Tettigonidae) is a highly nutritious and luxurious insect delicacy that is consumed as a food source in many African countries. However, the nutrient profile of R. differens in different geographical regions have received limited research interest. Here, we provide comprehensive evidence of geographical impact on the nutrient profile of R. differens and its potential to meet the recommended dietary intake of the population. Our results demonstrated that proximate composition, fatty acids, amino acids, minerals, vitamins, and flavonoid contents of R. differens collected from five districts in Uganda varied considerably. The crude protein (28-45%), crude fat (41-54%), and energy (582-644 Kj/100 g) contents of R. differens exceed that reported from animal origins. The highest crude protein, crude fat, and carbohydrate contents of R. differens were recorded in Kabale, Masaka, and Kampala, respectively. A total of 37 fatty acids were identified with linoleic acid (omega-6 fatty acid) being the most abundant polyunsaturated fatty acid in R. differens from Kabale, Masaka, and Mbarara. All essential amino acids were recorded in R. differens, particularly histidine with values exceeding the daily requirement for adults. Mineral and vitamin content differed significantly across the five districts. The highest quantity of flavonoids was recorded in R. differens from Hoima (484 mg/100 g). Our findings revealed that R. differens could be considered as functional food ingredients capable of supplying essential macro- and micronutrients that are critical in curbing the rising food insecurity and malnutrition in the regions.

A new species of Dasylabris Radoszkowski, 1885 (Hymenoptera: Mutillidae) from India.

We report the complete mitochondrial genome of the Cretan bush cricket Poecilimon cretensis. The mitogenome consists of 13 protein-coding regions, 22 tRNAs, two rRNAs, and one control region. The length of mitogenome in P. cretensis varies between15477 and 15631 bp, mainly due to variability in control region. The start and stop codons of protein coding genes exhibit the general pattern in Phaneropterinae. Phylogenetic tree constructed with the mitogenome obtained during this study and 12 mitogenomes of Phaneropterinae downloaded from GenBank, placed P. cretensis in Barbitistini as sister group to Poecilimon luschani. Data indicate that the gene overlapping pattern exhibit strong phylogenetic signals.