Geographic variation in wing size and shape of the grasshopper Trilophidia annulata (Orthoptera: Oedipodidae): morphological trait variations follow an ecogeographical rule

Variety is the spice: The role of morphological variation of Triatoma infestans (Hemiptera, Reduviidae) at a macro-scale

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi (Chagas, 1909). One of the primary vectors of T. cruzi in South America is Triatoma infestans (Klug, 1834). This triatomine species is distributed across a huge latitudinal gradient, inhabiting domiciliary , peridomiciliary , and wild environments. Its wide geographic distribution provides an excellent opportunity to study the relationships between environmental gradients and intraspecific morphological variation. In this study, we investigated variations in wing size and shape in T. infestans across six ecoregions. We aimed to address the following questions: How do wing size and shape vary on a regional scale, does morphological variation follow specific patterns along an environmental or latitudinal gradient, and what environmental factors might contribute to wing variation? Geometric morphometric methods were applied to the wings of 162 females belonging to 21 T. infestans populations, 13 from Argentina (n = 105), 5 from Bolivia (n = 42), and 3 from Paraguay (n = 15). A comparison of wing centroid size across the 21 populations showed significant differences. Canonical Variate Analysis (CVA) revealed significant differences in wing shape between the populations from Argentina, Bolivia, and Paraguay, although there was a considerable overlap, especially among the Argentinian populations. Well-structured populations were observed for the Bolivian and Paraguayan groups. Two analyses were performed to assess the association between wing size and shape, geographic and climatic variables: multiple linear regression analysis (MRA) for size and Partial Least Squares (PLS) regression for shape. The MRA showed a significant general model fit. Six temperature-related variables, one precipitation-related variable, and the latitude showed significant associations with wing size. The PLS analysis revealed a significant correlation between wing shape with latitude, longitude, temperature-related, and rainfall-related variables. Wing size and shape in T. infestans populations varied across geographic distribution. Our findings demonstrate that geographic and climatic variables significantly influence T. infestans wing morphology.

Variation of the Tegmen and Cercus in Sinopodisma rostellocerca (Orthoptera: Acrididae: Melanoplinae) with Proposal of a New Synonym

Intraspecific variation is ubiquitous from individual traits to population level and plays an important role in a variety of fields. However, it is often ignored by systematists and comparative evolutionary biologists. In view of the limited knowledge of intraspecific variation, morphology-based identification has hindered the recognition of species borders and led to a great number of problems in the field of taxonomy and systematics. In this study, the intraspecific variation of the tegmen and cercus in Sinopodisma rostellocerca was examined, the variation patterns were summarized and the relationship between S. rostellocerca and S. hengshanica was discussed. The results showed that the intraspecific variation in the tegmen and male cercus was mainly manifested in the length and shape of the apical margin and dorso- and ventro-apical angles; this substantial variation occurred not only among intrapopulation individuals but also between the different sides of the same individuals, and all types of variation in S. hengshanica fell into the range of variation in S. rostellocerca, leading to the disappearance of the boundary between the two species. Therefore, S. hengshanica was herein considered as a new junior synonym of S. rostellocerca.

Geometric Morphometrics and Genetic Diversity Analysis of Chalcidoidea (Diglyphus and Pachyneuron) at Various Elevations

Eulophidae and Pteromalidae are parasitic wasps with a global distribution and import for the biological control of pests. They can be distributed in different altitude regions, but their morphological and genetic adaptations to different altitudes are unclear. Here, we collected specimens that belong to Eulophidae and Pteromalidae from various altitudinal gradients, based on integrated taxonomic approaches to determine the species composition, and we analyzed their body shape and size from different altitudes using geometric morphometrics. Then, we performed an analysis of the D. isaea population's haplotype genes to illustrate their genetic diversity. As a result, eight species that belong to two genera, Diglyphus Walker (Eulophidae) and Pachyneuron Walker (Pteromalidae), were identified, including two newly recorded species from China (D. chabrias and D. sabulosus). Through a geometric morphometrics analysis of body shape, we found that a narrow forewing shape and a widened thorax are the significant characteristics of adaptation to high-altitude environments in D. isaea and P. aphidis. Additionally, the body size studies showed a principal relationship between centroid size and altitude; the size of the forewings and thorax increases at higher altitudes. Next, using haplotype analysis, 32 haplotypes were found in seven geographic populations with high genetic diversity of this species. Our research provides preliminary evidence for the morphological and genetic diversity adaptation of parasitic wasps to extreme environments, and these data can provide important references for investigations on the ecological adaptability of parasitic wasps.

Insights into the mitochondrial cytochrome oxidase I (mt-COI) gene and wing morphometrics of Anopheles baimaii (Diptera: Culicidae) in malaria-endemic islands of Thailand

Anopheles baimaii (Diptera: Culicidae) significantly contributes to the transmission of parasites causing malaria in Southeast Asia and South Asia. This study examined the morphological (wing shape) and molecular (mitochondrial gene) variations of An. baimaii in four of Thailand's border islands, and also investigated the presence of Plasmodium parasites in these mosquitoes. No Plasmodium infections were detected in the samples. Significant differences in wing shape were observed in most island populations (p < 0.05). A single-linkage tree, constructed using Mahalanobis distances, clustered the populations into two groups based on geographical locations. Genetic variation in An. baimaii was also analyzed through cytochrome c oxidase subunit I (COI) gene sequences. This analysis identified 22 segregating sites and a low nucleotide diversity of 0.004. Furthermore, 18 distinct haplotypes were identified, indicating a high haplotype diversity of 0.825. Neutrality tests for the overall population revealed a significantly negative Fu's Fs value (-5.029), indicating a population expansion. In contrast, Tajima's D yielded a negative value (-1.028) that did not reach statistical significance. The mismatch distribution analysis exhibited a bimodal pattern, and the raggedness index was 0.068, showing no significant discrepancy (p = 0.485) between observed and expected distributions. Pairwise genetic differentiation assessments demonstrated significant differences between all populations (p < 0.05). These findings provide valuable insights into the COI gene and wing morphometric variations in An. baimaii across Thailand's islands, offering critical information for understanding the adaptations of this malaria vector and guiding future comprehensive research.

Effects of population variations and temperature on Chrysomya megacephala (Diptera: Calliphoridae) development: implications for estimating the postmortem interval

Forensic entomology requires knowledge of the developmental rates of the species that colonize a body after death to estimate the postmortem interval (PMI). These developmental rates may vary depending not only on the species but also on the geographic location due to population differences. Therefore, the objectives of this work were to determine the developmental duration of the forensically important fly Chrysomya megacephala under constant controlled and field condition temperatures and to compare these results, through a meta-analysis, with data reported by other authors on populations from different localities. For this, C. megacephala colonies were established in the laboratory, and the duration of the life cycle was studied at two controlled temperatures (25 °C and 27 °C) and field conditions (27.5 ± 3.2 °C). Analysis of variance was performed to determine differences in developmental time and larval length between constant laboratory temperatures and field conditions. A generalized linear model was performed with predictor variables extracted from the literature (diet, relative humidity, latitude, longitude) to evaluate the effect of population variation on developmental times. The results showed significant differences in developmental times between 25 and 27 °C. As expected, the complete life cycle of C. megacephala was shorter at 27 °C. Finally, the meta-analysis suggested differences between the developmental times of different populations, based on temperature and geographic location. The results of this study provide fundamental developmental data to use C. megacephala in PMI estimations. Finally, we suggest that, when making expert reports, information from local populations should be used to determine a more accurate and reliable PMI.

Detection of Hindwing Landmarks Using Transfer Learning and High-Resolution Networks

Hindwing venation is one of the most important morphological features for the functional and evolutionary analysis of beetles, as it is one of the key features used for the analysis of beetle flight performance and the design of beetle-like flapping wing micro aerial vehicles. However, manual landmark annotation for hindwing morphological analysis is a time-consuming process hindering the development of wing morphology research. In this paper, we present a novel approach for the detection of landmarks on the hindwings of leaf beetles (Coleoptera, Chrysomelidae) using a limited number of samples. The proposed method entails the transfer of a pre-existing model, trained on a large natural image dataset, to the specific domain of leaf beetle hindwings. This is achieved by using a deep high-resolution network as the backbone. The low-stage network parameters are frozen, while the high-stage parameters are re-trained to construct a leaf beetle hindwing landmark detection model. A leaf beetle hindwing landmark dataset was constructed, and the network was trained on varying numbers of randomly selected hindwing samples. The results demonstrate that the average detection normalized mean error for specific landmarks of leaf beetle hindwings (100 samples) remains below 0.02 and only reached 0.045 when using a mere three samples for training. Comparative analyses reveal that the proposed approach out-performs a prevalently used method (i.e., a deep residual network). This study showcases the practicability of employing natural images-specifically, those in ImageNet-for the purpose of pre-training leaf beetle hindwing landmark detection models in particular, providing a promising approach for insect wing venation digitization.

Bergmann's Rule under Rocks: Testing the Influence of Latitude and Temperature on a Chiton from Mexican Marine Ecoregions

Bergmann's rule relates the trend of increasing body size with higher latitudes, where colder climates are found. In the Mexican Pacific, three marine ecoregions are distinguishable across a latitudinal gradient. Stenoplax limaciformis is an abundant chiton species that is distributed on rocky shores in these ecoregions. Geometric morphometric analyses were performed to describe the shape and size variation of S. limaciformis between marine ecoregions that vary in sea surface temperature with latitude, thus testing Bergmann's rule. Individuals' body shape ranged from elongated to wide bodies. Although there was variation in chitons' body shape and size, the was no evidence of allometry among localities. The Gulf of California is the northernmost ecoregion evaluated in this work, where larger chitons were observed and lower sea surface temperature values were registered. The results suggest that S. limaciformis follows a trend to Bergmann's rule, such as endotherms. These mollusks do not need heat dissipation, but they do need to retain moisture. In addition, larger chitons were observed in zones with high primary productivity, suggesting that chitons do not delay their maturation due to food shortage.

Phenotypic variability in traits related to flight dispersal in the wing dimorphic species Triatoma guasayana

BACKGROUND

Triatoma guasayana is considered an emerging vector of Chagas disease in the Southern Cone of South America. The presence of a triatomine population with brachypterous individuals, in which both wings are reduced, has recently been reported for this species. The aim of the present study was to determine if flight-related traits varied across populations, if these traits could explain differences in flight capacity across populations and if flight-related traits are associated with geographic and/or climatic variation.

METHODS

The study involved 66 male T. guasayana specimens from 10 triatomine populations. Digital images of wing, head and pronotum were used to estimate linear and geometric morphometric variables. Variations in size and shape were analysed using one-way analysis of variance and canonical variate analysis (CVA), respectively. Mantel tests were applied to analyse the relationship between morphometric and geographic distances, and the association between size measurements was analysed using Pearson's correlation. We explored covariation between size and shape variables using partial least square analyses (PLS). The association of geographic and climatic variables with size measurements was tested using linear regression analyses. We performed PLS analyses for shape measurements.

RESULTS

Wing size differed significantly across triatomine populations. The CVA showed that wing shape of the brachypterous population is well discriminated from that of the other populations. The Mantel test showed a positive and significant association between wing shape and geographic distances. The heads of the brachypterous population were significantly larger than those of the other populations. Similar to wing shape, the head shape of the brachypterous population was well discriminated from those of the other populations. Pronotum width did not show significant differences across populations. Geographic and climatic factors were associated with size and shape of both the wing and head, but not with pronotum width.

CONCLUSIONS

Most of the traits related to flight dispersal varied across populations. Wing shape and head shape were found to be better markers for differentiated morphological variation across populations. Head measurements also varied in accordance with this condition. Geographic and climatic variables were associated with most of the flight-related traits.

Cold Acclimation and Supercooling Capacity of Agasicles hygrophila Adults

Agasicles hygrophila Selman and Vogt is used in the biological control of the invasive weed Alternanthera philoxeroides (Mart.) Griseb. However, with the northward establishment of A. philoxeroides in China, the weak adaptivity of A. hygrophila to cold weather has resulted in the ineffective control of A. philoxeroides in northern China. Cold acclimation can significantly enhance insect cold tolerance, enabling them to cope with more frequent climate fluctuations. To improve the biological control efficacy of A. hygrophila in cold climates, we compared the effects of rapid cold hardening and acclimation on A. hygrophila under laboratory conditions. On initially transferring adults from 26 to -10 °C for 2 h, mortality reached 80%. However, when pre-exposed to 0 °C for 2 h and then transferred to -10 °C for 2 h, adult mortality was reduced to 36.67%. These findings indicate that cold acclimation can enhance the cold tolerance of A. hygrophila under laboratory conditions. However, the beneficial cold acclimation effects waned after more than 15 min of recovery at 26 °C. Exposure to 15 °C for 24 h or gradual cooling from 0 to -10 °C at 1 °C·min^-1 also induced cold acclimation, indicating that long-term cold and fluctuating cold acclimation are also potentially effective strategies for enhancing low-temperature tolerance.

Intraspecific variation in wing geometry among Tabanus rubidus (Diptera: Tabanidae) populations in Thailand

Tabanus rubidus (Wiedemann, 1821) (Diptera: Tabanidae) is a hematophagous insect of veterinary and medical importance and is the predominant Tabanus spp. in Thailand. It is a potential mechanical vector of Trypanosoma evansi, which causes surra in domestic and wild animals. Wing geometric morphometrics is widely used as morphological markers for species identification and to assess the insect population structure. Herein, we investigated the intraspecific variation in wing geometry among T. rubidus populations in Thailand using landmark-based geometric morphometric analysis. Tabanus rubidus females were collected from five populations in four geographical regions in Thailand. The left wings of 240 specimens were removed and digitized using 22 landmarks for analysis. While wing size variations were found between some populations, wing shape variations were detected in all. These intraspecific variations in T. rubidus populations indicate an adaptive response to the local environmental conditions.

Large-Scale Geographic Size Variability of Cyprideis torosa (Ostracoda) and Its Taxonomic and Ecologic Implications

Body-size variability results from a variety of extrinsic and intrinsic factors (environmental and biological influences) underpinned by phylogeny. In ostracodes it is assumed that body size is predominantly controlled by ecological conditions, but investigations have mostly focused on local or regional study areas. In this study, we investigate the geographical size variability (length, height, and width) of Holocene and Recent valves of the salinity-tolerant ostracode species Cyprideis torosa within a large geographical area (31°–51° latitude, and 12°–96° longitude). It is shown that distant local size clusters of Cyprideis torosa are framed within two large-scale geographical patterns. One pattern describes the separation of two different size classes (i.e., morphotypes) at around ∼42° N. The co-occurrence of both size morphotypes in the same habitats excludes an environmental control on the distribution of the morphotypes but rather could point to the existence of two differentiated lineages. Generally, correlations between valve size and environmental parameters (salinity, geographical positions) strongly depend on the taxonomic resolution. While latitude explains the overall size variability of C. torosa sensu lato (i.e., undifferentiated for morphotypes), salinity-size correlations are restricted to the morphotype scale. Another large-scale pattern represents a continuous increase in valve size of C. torosa with latitude according to the macroecological pattern referred as Bergmann trend. Existing explanations for Bergmann trends insufficiently clarify the size cline of C. torosa which might be because these models are restricted to intraspecific levels. The observed size-latitude relationship of C. torosa may, therefore, result from interspecific divergence (i.e., size ordered spatially may result from interspecific divergence sorting) while environmental influence is of minor importance. Our results imply that geographical body-size patterns of ostracodes are not straightforward and are probably not caused by universal mechanisms. Consideration of phylogenetic relationships of ostracodes is therefore necessary before attempting to identify the role of environmental controls on body size variability.

Genomic shifts, phenotypic clines and fitness costs associated with cold-tolerance in the Asian tiger mosquito

Climatic variation is a key driver of genetic differentiation and phenotypic traits evolution, and local adaptation to temperature is expected in widespread species. We investigated phenotypic and genomic changes in the native range of the Asian tiger mosquito, Aedes albopictus. We first refine the phylogeographic structure based on genome-wide regions (1,901 ddRAD SNPs) from 41 populations. We then explore the patterns of cold adaptation using phenotypic traits measured in common garden (wing size and cold tolerance) and genotype–temperature associations at targeted candidate regions (51,706 exon capture SNPs) from 9 populations. We confirm the existence of three evolutionary lineages including clades A (Malaysia, Thailand, Cambodia, and Laos), B (China and Okinawa), and C (South Korea and Japan). We identified temperature-associated differentiation in fifteen out of 221 candidate regions but none in ddRAD regions, supporting the role of directional selection in detected genes. These include genes involved in lipid metabolism and a circadian clock gene. Most outlier SNPs are differently fixed between clades A and C, while clade B has an intermediate pattern. Females are larger at higher latitude yet produce no more eggs, which might favor the storage of energetic reserves in colder climate. Non-diapausing eggs from temperate populations survive better to cold exposure than those from tropical populations, suggesting they are protected from freezing damages but this cold tolerance has a fitness cost in terms of egg viability. Altogether, our results provide strong evidence for the thermal adaptation of A. albopictus across its wide temperature range.

The Comparison of Gut Bacteria Communities and the Functions Among the Sympatric Grasshopper Species From the Loess Plateau

Gut bacteria exert effects on the health and fitness of their insect hosts. Grasshoppers are an important part of the grassland ecosystem and provide important ecosystem services. As the most valuable feature in grassland ecosystem, the compositions and potential influences of gut bacterial in herbivorous grasshoppers in the same ecological environment are essential but undetermined. To facilitate such studies, we collected nine species of grasshoppers (n = 110) from a rebuild grassland on the Loess Plateau in northern Shaanxi, China, which is a representative area of ecosystem restoration model. We characterized the composition and function of the gut bacteria. We found that 326 OTUs were exhibited in all grasshoppers in which Enterobacter, Pantoea, Bacillus, and Spiroplsma are dominant. Among them, 18 OTUs were shared across all nine species of grasshoppers. The predicted function showed that the majority function of those OTUs were involved in survival dependent processes including membrane transport, carbohydrate metabolism, amino acid metabolism, and DNA replication and repair. The composition of gut bacteria is specific to each grasshopper species, and the bacteria community is most various in Trilophidia annulata. These results highlight the gut bacterial community diversity in different grasshopper species. Our findings are necessary for better understanding the relationships between this important herbivorous insect and their microbiomes and have the potential contribution of evaluating the revegetation and ecosystem management in this area.

Wing Phenotypic Variation among Stomoxys calcitrans (Diptera: Muscidae) Populations in Thailand

Stomoxys calcitrans (Linnaeus, 1758) (Diptera: Muscidae) is a cosmopolitan hematophagous ectoparasite of veterinary and medical importance. It is an important mechanical vector of several animal pathogens and can cause significant economic losses. However, the morphological variation of this species remains unknown. This study aimed to investigate the phenotypic variation in the wing size and shape of S. calcitrans populations in Thailand based on a landmark-based geometric morphometric approach. Specimens were collected from five populations in five geographical regions in Thailand. A total of 490 left wings of S. calcitrans (245 female and 245 male individuals) were used for geometric morphometric analysis. Wing size differences were detected between some populations of S. calcitrans, whereas wing shape differences were found among populations. Therefore, the phenotypic variation in S. calcitrans populations indicated that these populations are adaptive responses to local environmental pressures, suggesting the presence of phenotypic plasticity in this species.

Geometric morphology and population genomics provide insights into the adaptive evolution of Apis cerana in Changbai Mountain

Background

Exploration of adaptive evolution of organisms in response to environmental change can help to understand the evolutionary history of species and the underlying mechanisms of adaptation to local environments, thus guiding future conservation programmes. Before the introduction of Apis mellifera in China, eastern honey bees (Apis cerana) were the only species used for beekeeping in this region. In the mountains of Changbai, populations of A. cerana are considered a distinct ecotype of the species which formed through the distinct selective pressures in this area over time.

Result

We performed a measure of 300 wing specimens of eastern honey bees and obtained the geometric morphological variation in the wing of A. cerana in Changbai Mountain. A total of 3,859,573 high-quality SNP loci were yielded via the whole-genome resequencing of 130 individuals in 5 geographic regions.

Conclusion

Corresponding geometric morphology and population genomics confirmed the particularity of the A. cerana in Changbai Mountain. Genetic differentiation at the subspecies level exists between populations in Changbai Mountain and remaining geographic regions, and a significant reduction in the effective population size and an excessive degree of inbreeding may be responsible for a substantial loss of population genetic diversity. Candidate genes potentially associated with cold environmental adaptations in populations under natural selection were identified, which may represent local adaptations in populations. Our study provided insights into the evolutionary history and adaptation of A. cerana in Changbai Mountain, as well as its conservation.

Spatial population structure: patterns of adaptation in populations of the water hyacinth grasshopper Cornops aquaticum (Bruner 1906)

The water hyacinth grasshopper Cornops aquaticum (Bruner 1906) constitutes an appropriate model to assess phenotypic and karyotypic variability in the context of differentiation and adaptation of insect populations because it occurs over a wide latitudinal range. This study represents a general analysis of phenotype, karyotype and molecular variation in native populations of C. aquaticum in South America. This is also relevant because this insect is considered a promising biological control agent of water hyacinth, a native South American aquatic plant but a pest in South Africa. Along Paraná and Uruguay River Basins, body size correlated negatively with latitude, and positively so with temperature and rainfall in both sexes. To test whether the chromosomal and phenotypic patterns were adaptive, we compared them with neutral microsatellite loci variation in populations from the medium and lower course of the Paraná River. Firstly, the lack of pairwise association between karyotype and phenotype distance matrixes with that of neutral loci suggested non-neutrality. Secondly, phenotypic differentiation for all morphometric traits (PST) was significantly larger than molecular differentiation (FST), indicating a prevailing divergence selection effect on the observed phenotypic patterns. Finally, the phenotypic and genotypic spatial structures - inferred from Bayesian approaches - were discordant: neutral genetic structure clustered together most populations except for the two southernmost, downstream ones, whereas phenotypic spatial structure groups together all the deltaic populations and singles out the two northernmost ones. The results suggest directional selection leading to higher centric fusion frequencies in the downstream populations and favouring morphometric optimal differences in relation to the environment.

Conserved and Divergent Aspects of Plasticity and Sexual Dimorphism in Wing Size and Shape in Three Diptera

The ability of powered flight in insects facilitated their great evolutionary success allowing them to occupy various ecological niches. Beyond this primary task, wings are often involved in various premating behaviors, such as the generation of courtship songs and the initiation of mating in flight. These specific functions imply special adaptations of wing morphology, as well as sex-specific wing morphologies. Although wing morphology has been extensively studied in Drosophila melanogaster (Meigen, 1830), a comprehensive understanding of developmental plasticity and the impact of sex on wing size and shape plasticity is missing for other Diptera. Therefore, we raised flies of the three Diptera species Drosophila melanogaster, Ceratitis capitata (Wiedemann, 1824) and Musca domestica (Linnaeus, 1758) at different environmental conditions and applied geometric morphometrics to analyze wing shape. Our data showed extensive interspecific differences in wing shape, as well as a clear sexual wing shape dimorphism in all three species. We revealed an impact of different rearing temperatures on wing shape in all three species, which was mostly explained by plasticity in wing size in D. melanogaster. Rearing densities had significant effects on allometric wing shape in D. melanogaster, while no obvious effects were observed for the other two species. Additionally, we did not find evidence for sex-specific response to different rearing conditions in D. melanogaster and C. capitata, while a male-specific impact of different rearing conditions was observed on non-allometric wing shape in M. domestica. Overall, our data strongly suggests that many aspects of wing morphology underly species-specific adaptations and we discuss potential developmental and functional implications of our results.

Evidence of phenotypic plasticity along an altitudinal gradient in the dung beetle Onthophagus proteus

Background

High altitude insects are an ecologically specialized group and possess a suite of adaptions which allow persistence in the inhospitable conditions often associated with mountain tops. Changes in body coloration and reductions or increases in body size are thought to be examples of such adaptions. Melanic individuals, or individuals containing high levels of eumelanin, possess several traits which increase resistance to ultraviolet radiation and desiccation, while aiding thermoregulation. Trait variation is often observed in dung beetles and is associated with dimorphism and sexual selection. In this study, we identified trait changes which occur across an altitudinal gradient by measuring morphological color and body size traits in a montane insect.

Methods

Using standard digital photography and Image J, we examined individuals of Afromontane dung beetle Onthophagus proteus. Individuals were classified according to sex and color morph to identify intrasexual variance. Nine morphometric traits were measured per beetle to identify patterns of morphology across discrete 500 m altitude segments.

Results

The results of this study provide one of the first descriptions of trait changes associated with elevation in an African dung beetle. We suggest that color polymorphism in Onthophagus proteus might be at least partly driven by environmental factors as there is significantly increased melanism with increasing elevation and significant differences in color hues between altitude bands. We also suggest changes in horn length are density dependent, as we observed an increase in cephalic horn length at high elevations where O. proteus is the most abundant species.

Molecular and morphometric identification of pistachio psyllids with niche modeling of Agonoscena pistaciae (Hemiptera: Aphalaridae)

Species of Agonoscena (Hemiptera: Aphalaridae) are key pests of pistachio in all of the most important pistachio producing countries in the Old World. The efficiency and accuracy of DNA barcoding for the identification of Agonoscena species were tested using mitochondrial cytochrome c oxidase subunit 1 (mtCO1) and cytochrome b (cytb) gene sequences. Moreover, morphometric sexual dimorphism was studied. Finally, the potential geographical distribution of Agonoscena pistaciae, the most important pistachio pest, was calculated using the MaxEnt model. Similar relationships of clustering were found in the morphometric analysis and the molecular analyses with mtCO1 and cytb genes, with A. bimaculata and A. pistaciae being closely related, and A. pegani constituting their sister group. Although the results showed that the cytb gene is a better marker for barcoding in this group, the mtCO1 gene clearly separates the three psyllid species making mtCO1 suitable for diagnostic purposes. A geometric morphometric analysis showed that the distance between landmark number 7 (bifurcation of vein M) to the fore margin of the forewing, and the distance between landmarks number 6 (apex of vein Cu1b) and 11 (wing base), are the most important geometric characters for diagnosing the studied species. Moreover, the forewing shape of males vs females is similar in A. pistaciae and A. bimaculata but differs significantly in A. pegani. In the ecological niche modeling of the distribution of A. pistaciae, the most important contribution was made by the variable 'minimum temperature of coldest period'. The most suitable areas for A. pistaciae are restricted to Eastern, Southern and some parts of Central Iran.

The Effects of Locality and Host Plant on the Body Size of Aeolothrips intermedius (Thysanoptera: Aeolothripidae) in the Southwest of Poland

Aeolothrips intermedius is a thrips predator often found in phytocoenoses worldwide. Both the adults and larvae of this species prey on small invertebrates, including phytophagous species from Thysanoptera group. The aim of this study was to determine the morphological variability of the A. intermedius relative to the locality and, indirectly, to the species of host plant. Insects were collected from five localities in southwest Poland and five different host plants. For each of the sexes, six morphometric features were assessed: body length, length of antennae, wing length, head length, head width and length of pronotum. Additionally, the body mass for each individual was estimated. The findings revealed that in females, both the locality and host plant had a significant impact on almost all of these features. In males, the morphometric features under study correlated strongly with locality and only moderately with the host plant. Certain differences were observed between males and females, mainly in terms of antennae length. The results show that A. intermedius exhibits significant variability in this respect, which is indicative of the species’ phenotypic plasticity. The body length was the trait with the most distinct response to the locality and host plant.

The Prevalence of Single-Specimen/Locality Species in Insect Taxonomy: An Empirical Analysis

Although about two million species have been named, our knowledge about the biodiversity of many taxonomic groups remains inadequate and incomplete. There has been increased taxonomic effort for the discovery of more species and their geographical distribution information. During this process, species collected only from a single specimen/locality often appear. However, there are very few empirical data available to understand the current situation of single specimen/locality species in insect taxonomy. In this paper, we collected 1261 articles containing 4811 insect species from ZooKeys between 2009 and 2017, and we extracted data, including the publication date, number of specimens/locality, and DNA usage. Our analyses demonstrated that 21.53% and 21.74% of new species were described from only one specimen and one locality, respectively, and approximately half of all new species were published based on fewer than five specimens. Meanwhile, the rate of single-specimen species in papers with or without DNA data was 15.06% and 23.43%, respectively, which indicates that incorporating DNA data in species descriptions might effectively decrease the occurrence of single-specimen species. We suggest that taxonomists should adopt more beneficial practices, such as increasing specimen diversity, incorporating DNA data, and improving international collaboration, in the description of new species.

Changes in the Body Size of Carabid Beetles Along Elevational Gradients: A Multispecies Study of Between- and Within-Population Variation

Geographic variation in body size has fascinated biologists since the 19th century as it can provide insight into the evolution of the body size of various organisms. In this study, we investigated body size variation in eight carabid species/subspecies (Coleoptera: Carabidae) along elevational gradients in six Central European mountain ranges. First, we examined elevational variation in body size and whether female and male body sizes differed in their responses to elevation. Second, we examined intrapopulation variation in body size along an elevational gradient, and we compared the degrees of intrapopulation variation between males and females. The investigated species either followed a converse Bergmann's cline (Carabus auronitens auronitens Fabricius 1792; Carabus linnei Panzer 1810; Pterostichus melanarius (Illiger, 1798); Pterostichus pilosus (Host, 1789)) or their size was unaffected by elevation (Carabus auronitens escheri Palliardi, 1825; Carabus sylvestris sylvestris Panzer, 1796; Carabus sylvestris transsylvanicus Dejean, 1826; Pterostichus burmeisteri Heer, 1838). Females were the larger sex in all the investigated species, but the degree of sexual size dimorphism differed between species. In general, the degree of sexual size dimorphism showed no change with elevation. The degree of intrapopulation variation in body size slightly increased with elevation in C. sylvestris sylvestris and P. pilosus. Overall, the intrapopulation variation in body size significantly differed among the investigated carabid species. The existing literature on intrapopulation variation in the body size of insects is limited, but further investigation of this issue could provide a better understanding of the mechanisms that generate geographical clines.

Morphological Variation Tracks Environmental Gradients in an Agricultural Pest, Phaulacridium vittatum (Orthoptera: Acrididae)

Invertebrate pests often show high morphological variation and wide environmental tolerances. Knowledge of how phenotypic variation is associated with environmental heterogeneity can elucidate the processes underpinning these patterns. Here we examine morphological variation and relative abundance along environmental gradients in a widespread agricultural pest, native to Australia, the wingless grasshopper Phaulacridium vittatum (Sjöstedt). We test for correlations between body size, wing presence, and stripe polymorphism with environmental variables. Using multiple regression and mixed-effects modeling, body size and stripe polymorphism were positively associated with solar radiation, and wing presence was positively associated with foliage projective cover (FPC). There were no associations between body size or morphological traits with relative abundance. However, relative abundance was positively associated with latitude, soil moisture, and wind speed, but was negatively associated with FPC. Therefore, sites with low relative abundance and high forest cover were more likely to contain winged individuals. Overall, our results suggest that environmental and climatic conditions strongly influence the relative abundance and the distribution of morphotypes in P. vittatum, which is likely to affect dispersal and fitness in different landscapes. This knowledge is useful for informing how environmental change might influence the future spread and impact of this agricultural pest.

Identification, sexual dimorphism, and allometric effects of three psyllid species of the genus Psyllopsis by geometric morphometric analysis (Hemiptera, Liviidae)

Jumping plant lice (Hemiptera: Psylloidea) are considered important vectors of plant diseases and also economically important pests in agriculture and forest ecosystems. Three psyllid species Psyllopsisrepens Loginova, 1963, Psyllopsissecuricola Loginova, 1963, and Psyllopsismachinosus Loginova, 1963 associated with the ash tree Fraxinus are morphologically very similar. So far, their distinction has been possible only by comparing their male and female genitalia. In this research, forewing shape and size characteristics, sexual dimorphism and their allometric effects, using geometric morphometric analysis, were examined for identification purposes. The results showed significant differences in wing shape and size between the species studied. Based on the results, two species P. machinosus and P.securicola can be differentiated with the vein M1+2, as in P.securicola the vein M1+2 is located between Rs and M3+4 veins, but the vein M1+2 is closer to the vein M3+4 in P.machinosus; also, P.repens can be differentiated from the two species P.machinosus and P.securicola by vein M. Hence, the veins M1+2, M3+4, Rs and M were the most important wing characters for discrimination of the three species, especially in the field. The analysis also showed significant differences in wing shape and size between male and female of the three species, and the allometric analysis showed that significant shape differences still remain in constant size in P. machinosus and P.repens. Geometric changes in the forewings of both sexes for the three species are illustrated.

spalt is functionally conserved in Locusta and Drosophila to promote wing growth

Locusta has strong fly wings to ensure its long distance migration, but the molecular mechanism that regulates the Locusta wing development is poorly understood. To address the developmental mechanism of the Locusta flying wing, we cloned the Dpp target gene spalt (sal) and analyzed its function in wing growth in the Locusta. The Locusta wing size is apparently reduced with vein defects when sal is interfered by injection of dsRNA, indicating that sal is required for locust wing growth and vein formation. This function is conserved during the Drosophila wing development. To better understand sal’s function in wing growth, we then used Drosophila wing disc as a model for further study. We found that sal promotes cell proliferation in the whole wing disc via positive regulation of a microRNA bantam. Our results firstly unravel sal’s function in the Locusta wing growth and confirm a highly conserved function of sal in Locusta and Drosophila.