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Ecology and Evolution May 2024The expansion of forest cover and intensification of agriculture represent the main threats to the bush cricket , currently listed as Vulnerable globally by the IUCN and...
The expansion of forest cover and intensification of agriculture represent the main threats to the bush cricket , 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 population size in relation to environmental variables and prey availability and (2) predict abundance of in our study area for future monitoring in nearby territories. We found that the population of in our study area consists of 197 (±115) individuals with a detection probability of 21.01% (±11.09). Detection probability of further decreases on windy days. Moreover, we found that the investigated population of occupies suboptimal areas, as highlighted not only by the predicted abundances but also by the association between 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 is linked) into small and fragmented patches that are suboptimal and insufficient to host viable populations.
PubMed: 38770125
DOI: 10.1002/ece3.11381 -
Biology Open Jun 2024Trait polymorphisms are widespread in nature, and explaining their stable co-existence is a central problem in ecology and evolution. Alternative reproductive tactics,...
Trait polymorphisms are widespread in nature, and explaining their stable co-existence is a central problem in ecology and evolution. Alternative reproductive tactics, in which individuals of one or more sex exhibit discrete, discontinuous traits in response to reproductive competition, represent a special case of trait polymorphism in which the traits are often complex, behavioural, and dynamic. Thus, studying how alternative reproductive tactics are maintained may provide general insights into how complex trait polymorphisms are maintained in populations. We construct a spatially explicit individual-based model inspired from extensively collected empirical data to address the mechanisms behind the co-existence of three behavioural alternative reproductive tactics in males of a tree cricket (Oecanthus henryi). Our results show that the co-existence of these tactics over ecological time scales is facilitated by the spatial structure of the landscape they inhabit, which serves to equalise the otherwise unequal mating benefits of the three tactics. We also show that this co-existence is unlikely if spatial aspects of the system are not considered. Our findings highlight the importance of spatial dynamics in understanding ecological and evolutionary processes and underscore the power of integrative approaches that combine models with empirical data.
Topics: Male; Gryllidae; Animals; Sexual Behavior, Animal; Reproduction; Biological Evolution; Phenotype
PubMed: 38738657
DOI: 10.1242/bio.060307 -
ZooKeys 2024The songs of seven grasshopper species of subfamily Gomphocerinae from Russia, Ukraine, Georgia, and Kazakhstan were studied. We analysed not only the sound, but also...
The songs of seven grasshopper species of subfamily Gomphocerinae from Russia, Ukraine, Georgia, and Kazakhstan were studied. We analysed not only the sound, but also the stridulatory movements of the hind legs to more entirely describe the songs. In , , and , the legs are moved in a relatively simple pattern; four other species, , , , and demonstrate more complex leg movements. In six of the seven species studied, the courtship songs contain more sound elements than the calling songs. The highest number of courtship sound elements was found in and The different parts of a remarkably long stridulatory file in are thought to participate in the production of different sound elements. The songs in are shown for the first time. This species produces sound not only by common stridulation but also by wing beats. A relationship of to some other species of the genus , which are able to crepitate, is discussed. We also analyse the frequency spectra of the songs. A maximum energy of the song power spectra in six species studied lies in ultrasound range (higher than 20 kHz). In only , the main peaks in the song power spectra lie lower than 20 kHz. The courtship behaviour in , , and was shown to include conspicuous visual display (movements of antennae, palps and the whole body).
PubMed: 38736699
DOI: 10.3897/zookeys.1200.118422 -
PloS One 2024Cricket Frass Fertilizer (CFF) was tested for its efficiency and potential as a fertilizer on the growth of green beans (Phaseolus vulgaris L.) in central Madagascar...
Cricket Frass Fertilizer (CFF) was tested for its efficiency and potential as a fertilizer on the growth of green beans (Phaseolus vulgaris L.) in central Madagascar from April 2020 to October 2020. We grew green beans experimentally for 93 days with seven different fertilizer treatments: NPK 200 kg/ha (0.47 g of N/plant), GUANOMAD (guano from bat) 300 kg/ha (0.26 g of N/ plant), CFF 100 kg/ha (0.12 g of N/plant), CFF 200 kg/ha (0.24 g of N/plant), CFF 300 kg/ha (0.38 g of N/plant), CFF 400 kg/ha (0.52 g of N/plant), and no fertilizer (0 g of N/plant). Three plant traits were measured: survival proportion, vegetative biomass, and pod biomass. The survival proportion of plants treated with the highest dose of CFF (400 kg/ha, 88.1%), NPK (79.8%), and GUANOMAD (81.2%) were similar, but plants treated with the former yielded significantly higher vegetative (35.5 g/plant) and pod biomass (11 g/plant). These results suggest that fertilizing green beans with CFF at a 400 kg/ha dose is sufficient for plant survival and growth, and improves pod production. In Madagascar where soil quality is poor, dependence on imported chemical fertilizers (NPK) and other organic fertilizer (GUANOMAD) can be reduced. Cricket Frass Fertilizer can be used as an alternative sustainable fertilizer for beans.
Topics: Fertilizers; Phaseolus; Biomass; Madagascar; Animals; Gryllidae
PubMed: 38722876
DOI: 10.1371/journal.pone.0303080 -
Philosophical Transactions of the Royal... Jun 2024Night-time light can have profound ecological effects, even when the source is natural moonlight. The impacts of light can, however, vary substantially by taxon, habitat...
Night-time light can have profound ecological effects, even when the source is natural moonlight. The impacts of light can, however, vary substantially by taxon, habitat and geographical region. We used a custom machine learning model built with the Python package to investigate the effects of moonlight on the calling activity of neotropical forest katydids over multiple years. We prioritised species with calls that were commonly detected in human annotated data, enabling us to evaluate model performance. We focused on eight species of katydids that the model identified with high precision (generally greater than 0.90) and moderate-to-high recall (minimum 0.35), ensuring that detections were generally correct and that many calls were detected. These results suggest that moonlight has modest effects on the amount of calling, with the magnitude and direction of effect varying by species: half of the species showed positive effects of light and half showed negative. These findings emphasize the importance of understanding natural history for anticipating how biological communities respond to moonlight. The methods applied in this project highlight the emerging opportunities for evaluating large quantities of data with machine learning models to address ecological questions over space and time. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.
Topics: Forests; Animals; Vocalization, Animal; Machine Learning; Light
PubMed: 38705184
DOI: 10.1098/rstb.2023.0110 -
PloS One 2024Gryllus bimaculatus (Orthoptera: Gryllidae) is widely considered an excellent nutrient source for food and feed. Despite its economic importance, there is limited...
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.
Topics: Animals; Gryllidae; Temperature; Female; Male; Life Cycle Stages
PubMed: 38687812
DOI: 10.1371/journal.pone.0300438 -
Animals : An Open Access Journal From... Apr 2024Sympatric closely related species may experience interspecific trophic competition due to ecological similarity; they may isolate in terms of diet or habitat use as a...
Sympatric closely related species may experience interspecific trophic competition due to ecological similarity; they may isolate in terms of diet or habitat use as a strategy to avoid competition. The body tissues of consumers contain stable isotope signatures information that can be applied to infer their dietary information. In this study, δC and δN stable isotopes were analyzed to determine the dietary information and trophic niches of sympatric coexisting and . The results showed that the food sources of and were from six orders, including Orthoptera, and the cumulative contribution rate was 99.97%, with the two species eating similar diets but at different rates. The larger δC of indicates that it had a wider range of habitats for feeding, while the difference in δN values was not significant ( > 0.05), indicating that both species feed on similar nutrient levels. As determined by Bayesian ellipses, the isotopic niches of and were differentiated; the isotopic niche width of is 2.69‱, which was larger than that of (0.73‱), indicates that differentiation between the two species in diet or habitat use reduced competition. Trophic niche differentiation and differences in foraging proportions may be the principal resource allocation mechanisms behind and coexistence.
PubMed: 38672294
DOI: 10.3390/ani14081146 -
Scientific Data Apr 2024The pygmy grasshoppers, which belong to the superfamily Tetrigoidea, exhibit remarkable environmental adaptability. However, no study has yet reported a reference genome...
The pygmy grasshoppers, which belong to the superfamily Tetrigoidea, exhibit remarkable environmental adaptability. However, no study has yet reported a reference genome for this group. In this study, we assembled a high-quality chromosome-scale genome of Eucriotettix oculatus, which survive in the environment heavily polluted by heavy metals, achieved through Illumina and PacBio sequencing, alongside chromosome conformation capture techniques. The resulting genome spans 985.45 Mb across seven chromosomes (range: 71.55 to 266.65 Mb) and features an N50 length of 123.82 Mb. Chr5 is considered to be the single sex chromosome (X). This genome is composed of 46.42% repetitive elements and contains 14,906 predicted protein-coding genes, 91.63% of which are functionally annotated. Decoding the E. oculatus genome not only promotes future studies on environmental adaptation for the pygmy grasshopper, but also provides valuable resources for in-depth investigation on phylogeny, evolution, and behavior of Orthoptera.
Topics: Animals; Grasshoppers; Genome, Insect; Chromosomes, Insect; Phylogeny
PubMed: 38670991
DOI: 10.1038/s41597-024-03276-2 -
Toxics Mar 2024The present study applied a non-invasive method to analyse anthropogenic particles and prey items in white stork () pellets. Pellets ( = 20) were obtained from white...
The present study applied a non-invasive method to analyse anthropogenic particles and prey items in white stork () pellets. Pellets ( = 20) were obtained from white stork nests during the 2020 breeding season from two sites in Croatia. In total, 7869 anthropogenic particles were isolated. The majority of particles were fragments, while previous studies on other birds often reported fibres. An ATR-FTIR polymer analysis detected glass and construction and building materials, as well as several compounds associated with plastic masses. Polymer investigation revealed the presence of dotriacontane and octacosane, which are by-products of polyethylene (PE) degradation and transformation. Additionally, the detection of vinylidene chloride (VDC) highlights the historical contribution of polyvinylidene chloride (PVDC) to plastic pollution. Significant variation in particle quantity and size between the sampling sites was detected, with larger particles found at sites associated with the metal mechanical engineering industry and agriculture. Prey assessment revealed chitin remains of large insects such as Orthoptera and Coleoptera. This research confirms the potential of pellet analysis as a valuable tool for assessing the presence of anthropogenic particles in the environment. However, further research is needed to fully understand the extent of particle ingestion, particle sources and potential impact.
PubMed: 38668458
DOI: 10.3390/toxics12040236 -
Insects Mar 2024The pygmy grasshopper, , is a Chinese endemic species with an exceedingly limited distribution and fragile population structure, rendering it vulnerable to extinction....
The pygmy grasshopper, , is a Chinese endemic species with an exceedingly limited distribution and fragile population structure, rendering it vulnerable to extinction. We present a high-continuity, chromosome-scale reference genome assembly to elucidate this species' distinctive biology and inform conservation. Employing an integrated sequencing approach, we achieved a 970.40 Mb assembly with 96.32% coverage across seven pseudo-chromosomes and impressive continuity (N50 > 220 Mb). Genome annotation achieves identification with 99.2% BUSCO completeness, supporting quality. Comparative analyses with 14 genomes from Orthoptera-facilitated phylogenomics and revealed 549 significantly expanded gene families in associated with metabolism, stress response, and development. However, genomic analysis exposed remarkably low heterozygosity (0.02%), implying a severe genetic bottleneck from small, fragmented populations, characteristic of species vulnerable to extinction from environmental disruptions. Elucidating the genetic basis of population dynamics and specialization provides an imperative guideline for habitat conservation and restoration of this rare organism. Moreover, divergent evolution analysis of the CYP305m2 gene regulating locust aggregation highlighted potential structural and hence functional variations between Acrididae and Tetrigidae. Our chromosomal genomic characterization of advances Orthopteran resources, establishing a framework for evolutionary developmental explorations and applied conservation genomics, reversing the trajectory of this unique grasshopper lineage towards oblivion.
PubMed: 38667352
DOI: 10.3390/insects15040223