Male Wing Research Articles

Helen's twins in the Balkans: discovery of two new Paraptychoptera Tonnoir, 1919 species closely related to P.helena Peus, 1958, with systematic revision of the "lacustris" group (Diptera, Ptychopteridae).

Ptychopteracastor Keresztes & Kappert, sp. nov. and P.pollux Keresztes & Török, sp. nov. both belong to the subgenus Ptychoptera (Paraptychoptera)Tonnoir (1919) and are described from boggy headwaters in the south Balkan area. These new species are closely related to the range-restricted P.helena Peus, 1958, which is known only from Oiti village, Mount Oeta, Phthioitis region, Greece and, together with P.lacustris, forms a morphologically well-defined unit in the subgenus Paraptychoptera. Based on cladistic analyses of 53 different morphological characters using the male antenna, wing, and genital structures, a general revision of the “lacustris” group is proposed with a dichotomous key of Paraptychoptera species.

Sexual selection on population-level mating opportunities drives morph ratios in a fig wasp with extreme male dimorphism

BackgroundAlternative mating tactics are widespread in animals and associated with extreme morphological polymorphism in some insects. Some fig wasps have both highly modified wingless males and dispersing winged males. Wingless males mate inside figs before females disperse, while winged males mate elsewhere after dispersal. Hamilton proposed a model for this system with morphs determined by alternative alleles. This has an equilibrium where the proportion of winged males equals the proportion of females dispersing unmated; i.e. the proportion of matings that they obtain. Previously, we have shown qualitative support for this prediction across nine wing-dimorphic fig wasp species. Here I test the quantitative prediction in the fig wasp Pseudidarnes minerva. In addition, some fig wasp species that lack winged males, but have two wingless morphs, show a conditional strategy with morph determination influenced by the number of wasps developing in a patch. I also test for this alternative pattern in the wing-dimorphic P. minerva.ResultsI sampled 114 figs that contained a mean of 2.1 P. minerva wasps from 44 trees across four sites in Sydney, Australia. At the whole population level, the proportion of winged males (0.84 or 0.79 corrected for sampling bias) did not differ significantly from the proportion of unmated females (0.84), providing strong quantitative support for the prediction of Hamilton’s model. In addition, there was no evidence for other factors, such as local mate competition or fighting between wingless males, that could violate simplifying assumptions of the model. Meanwhile, the proportion of winged males was not correlated with the number of wasps per fig, providing no evidence for a conditional strategy.ConclusionThe morph ratio in P. minerva is consistent with Hamilton’s simple Mendelian strategy model, where morph ratios are set by average mating opportunities at the population level. This contrasts with some fig wasps from another subfamily that show conditional morph determination, allowing finer scale adaptation to fig-level mating opportunities. However, these conditional cases do not involve wing polymorphism. Male polymorphism is common and variable in fig wasps and has evolved independently in multiple lineages with apparently different underlying mechanisms.

Exploratory Analysis of Color Forms' Variability in the Invasive Asian Lady Beetle Harmonia axyridis (Pallas 1773).

Simple SummaryIn the following study, methods of geometric morphometrics were used to identify invasive forms of Harmonia axyridis. The study confirms the efficiency of geometric morphometrics as a tool for identifying minimal shape plasticity in wing shape and patterns of sexual shape dimorphism among invasive forms. Although more detailed studies are needed for further clarity, the study demonstrates that these methods can analyze phenotypic differences among the forms and reveal subtle phenotypic changes that explain genetic alterations within an invasive H. axyridis species.The Asian ladybird (Harmonia axyridis Pallas), native to Asia, is one of the 100 most invasive species in the world and has spread worldwide. This study aimed to characterize color forms of H. axyridis in Croatia and to analyze the variability of wing shape between populations and indicated forms. Geometric morphometric methods were used to analyze a total of 129 left and right wings in males and 126 left and right wings in females of H. axyridis collected from four different sites in Croatia. The results show a significant difference in wing shapes between the studied forms. Each form had its own specific morphotype that likely originated under the influence of genetic changes in the species. This study demonstrates that the use of geometric morphometric analysis is effective in studying the variability in H. axyridis populations. As this study is the first of its kind, for further clarity, it is necessary to conduct additional studies on a larger number of sites and an equal number of individuals of all forms.

Male Chemical Signalling to Recruit Females in the Greater Short-Nosed Fruit Bat Cynopterus sphinx

Mate attraction via chemosignalling is common in group-living mammals. In the greater short-nosed fruit bats, Cynopterus sphinx, it remains unclear whether males use chemosignals to attract females. Here, we use field observations to describe patterns of male chemosignalling in this species, then use preference test in captivity to infer the function of chemosignals. We observed that males engage in chemosignalling through wing fanning after marking their leaf ‘tent' roosts with saliva. The male fanned each wing alternatively and vigorously and performed frequent tongue flicks to the wing membrane. Such behaviour is exhibited towards females that returned to the tent. Afterwards, the male embraced the female with both wings. Wing fanning and tent marking occurred more often during the mating season than the non-mating season. To infer the role of chemosignals in recruiting females, we performed two different choice tests. In the first test, we tested whether females preferred the tent containing cotton balls that were rubbed gently and repeatedly on the ventral side of the plagiopatagium of the male, versus a control tent without any conspecific odour. In the second test, we tested whether females preferred a tent that was marked by a male's saliva versus a control tent without such markings. The result of both tests indicated that females recognized the saliva and ‘scent’ from the wings of males, since females always preferred tents with male chemosignals over the controls. Our findings suggest that the recruitment of females and subsequent formation of a harem in the greater short-nosed fruit bats is influenced by male chemosignals.

Key and atlas to the genus Trichocera MEIGEN in Europe (Diptera, Trichoceridae)

The key presents all 59 species of the genus Trichocera MEIGEN which occur in Europe. Four subgenera are represented: Trichocera MEIGEN 1803 (five species), Metatrichocera DAHL 1967 (seven species), Saltrichocera KRZEMIÑSKA 2002 (35 species), and Staryia KRZEMIÑSKA & GORZKA 2016 (13 species). The type material of two species, one from North America and one from Asia, are described (Trichocera columbiana ALEXANDER, 1927 and T. arctica LUNDSTRÖM, 1915), whose identities cause some problems and whose presence in the northern regions of Europe is possible. Two new species are described, Trichocera ( Saltrichocera ) longa, n. sp., and T. (Staryia) oulankae, n. sp. Trichocera versicolor is resurrected from synonymy; T. limpidipennis is synonymized with T. regelationis. There are separate keys to males and females; species are illustrated with camera pictures of diagnostic features: genitalia, antennae, and male tarsal claws, and additionally, wings and thoraces when only one sex is known, to enable further search. The state of knowledge of the genus in Europe and in the world is discussed.

Revealing the effects of cerium dioxide nanoparticles through the analysis of morphological changes in Chironomus riparius

Due to their many practical applications, engineered cerium dioxide (CeO2) nanoparticles (NPs) are commonly used today, although there are justified concerns about the environmental risks of their usage. Studies to date have shown that CeO2 NPs do not pose a lethal hazard to hydrobiocenoses at environmentally relevant concentrations, but that they induce significant negative sublethal effects. Therefore, intensive work is being done on the adaptation of standard ecotoxicological tests with the development of new, sublethal biomarkers. The present study aims to examine the sublethal effects of prolonged exposure to CeO2 NPs (2.5; 25; 250 and 2500 mg of CeO2 NPs per 1 kg of sediment) on the morphological features of the non-biting aquatic midge Chironomus riparius. Morphological variation was examined by means of two approaches: (1) Deformity rate analysis (analysis of visible morphological malformations) and (2) Geometric morphometric analysis (analysis of differences in the size and shape of the larval mandibles and mentums, as well as adult male and female wings). Changes in all the morphological structures examined were observed using a geometric morphometric approach at low and very high concentrations of CeO2 NPs (2.5 and 2500 mg of CeO2 NPs per 1 kg of sediment). The potential reduction of sexual dimorphism resulting from downsizing of the wings in females was observed. These results indicate that the sublethal changes observed in chironomids exposed to CeO2 NPs are significant and may potentially lead to further changes in metabolism, diet and behavior, which may lead to repercussions of as yet unexamined proportions. Considering our findings, and the advantages of geometric morphometrics (precision, uniformity, accurate qualification, quantification, and visualization of fine morphological changes), this approach is proven to be an exceptional assessment tool, with great applicative potential in the ecotoxicological testing of nanoparticles.

Contributions to the knowledge of Neotropical Lycaenidae: taxonomy of Johnsonita/ Salazar amp; Constantino, 1995 with descriptions of seven new species (Theclinae: Eumaeini).

The Transandean-Andean genus Johnsonita Salazar Constantino, 1995 is revised on the basis of wing and genitalia morphology. Apart from eight species formerly placed in Johnsonita (Thecla assula Draudt, 1919; Thecla auda Hewitson, 1867; Thecla catadupa Hewitson, 1869; Thecla chaluma Schaus, 1902, Thecla chlamydem Druce, 1907; Thecla pardoa d'Abrera, 1995; Johnsonita johnsoni Salazar Constantino, 1995 and Johnsonita johnbanksi Bálint, 2003), seven new species are described: Johnsonita carpia Bálint, Boyer Pyrcz, sp. n. (Ecuador), Johnsonita iacinta Bálint, Boyer Pyrcz, sp. n. (Peru), Johnsonita ianusca Bálint, Lorenc-Brudecka Pyrcz, sp. n. (Ecuador), Johnsonita oxalida Bálint, Boyer Pyrcz, sp. n. (Peru), Johnsonita subcunicula Bálint, Cerdeña Pyrcz, sp. n. (Peru), Johnsonita turquisca Bálint, Boyer Pyrcz, sp. n. (Ecuador) and Johnsonita zubkova Bálint, Boyer Lorenc-Brudecka, sp. n. (Peru). One species, erroneously recorded from Bolivia under the name Thecla chaluma Schaus, 1902, is not formally described due to insufficient material. An identification key, type material revision, descriptions or redescriptions, and diagnosis for all the taxa recognized are given. Lectotypes for the nominal species Thecla assula Draudt, 1919 and Thecla chlamydem Druce, 1907 are designated. Male secondary wing characters are tabulated. A brief discussion on classification, life-history and male secondary characters of Johnsonita is presented.

Heat-distribution in the body and wings of the morpho dragonflyZenithoptera lanei(Anisoptera: Libellulidae) and a possible mechanism of thermoregulation

AbstractAnimals that live in hot environments must deal with extreme temperatures and overcome the constraints imposed by overheating. Some species exhibit remarkable adaptations to control body temperature, usually in the form of structures that act as thermal windows to cool down the body by dissipating heat. Here, we describe the case of the dragonfly Zenithoptera lanei, which inhabits open areas in the Neotropical Savannah and the Amazon. Males have striking and unique adaptations on the wings, not known in any other insect. The wings are covered with wax nanocrystals that reflect ultraviolet light and infrared radiation. Furthermore, the wing membrane is permeated by an intricate system of tracheae, another unique trait in Insecta. We hypothesized that these adaptations might be important not only for intraspecific communication, but also for thermoregulation. We analysed male body and wing temperatures and compared them with another dragonfly with common translucent wings. The results suggest that the dorsal wing surface acts as a cooling system, whereas the ventral surface might serve to elevate body temperature. Therefore, we conclude that Z. lanei possesses adaptations that are unique in nature; a complex system of thermoregulation with the dual function of cooling down or elevating body temperature, depending on wing position.

Images of Australian Odonata wings

A recently finished project has created an openly accessible, high-resolution, photographic library of wings of Australian dragonflies and damselflies, order Odonata. The library is an open resource for identification and research. Both male and female wings of 318 species of dragonfly and damselfly have been photographed with a specialist set-up using identified museum collection material. In general, both wings were removed from the insect body to produce an image with a minimum of visual artefacts. Each resulting image shows a pair of right wings, a scale, an identifying taxonomic name and sex.

Variación alar en los machos de la cucaracha cubana Byrsotria fumigata (Guérin-Méneville, 1857) (Blattodea: Blaberidae)

Byrsotria fumigata (Guérin-Méneville, 1857) is an endemic cockroach from Cuba which presents a remarkable variability in the male wings. This contribution addresses the differences in size and wing shape of males, previously reported on the literature. Brachypterous individuals are illustrated and the wing variation is quantified. The distribution of the species is expanded with two new localities.

How aware are swingers about their swing sex partners\u2019 risk behaviours, and sexually transmitted infection status?

BackgroundSwingers are members of a heterosexual couple who, as a couple, have sex with others. They constitute a hidden subpopulation that is at risk for sexually transmitted infections (STIs). This study aimed to determine swingers’ level of awareness about the STI risk (indicators: bisexual behaviour, number of sex partners, and STI status) of their swing sex partners (i.e. alters).MethodsIn this cross-sectional study, data were collected from a convenience sample of swingers who visited our STI clinic. The sample consisted of 70 participants (i.e. egos) and their 299 swing sex partners (i.e. alters) who had undergone an STI test at our clinic. We compared network data (i.e. information that egos provided about alters) and data stored in the electronic patient record (EPR) in our clinic (i.e. information provided by alters themselves). We assessed the agreement (correct estimation, overestimation and underestimation) between the network data and EPR data using chi-squared tests.ResultsEgos underestimated the bisexual behaviours of 37% of their male alters and overestimated the number of sex partners of 54 and 68% of their male and female alters, respectively. Egos correctly estimated the STI statuses of only 22% of the alters who had an STI during the past six months.ConclusionsThe participating swingers underestimated the bisexual behaviours of their male swing sex partners, overestimated their number of sex partners, and underestimated their positive STI status. Underestimating their alters’ STI statuses can cause swingers to underestimate their own STI risk and fail to implement preventive measures. The latter finding has implications for STI prevention. Therefore, more attention should be paid to swingers in general and the promotion of actual partner notification and STI testing among swingers in specific.

Sex-specific associations between life-history traits and a novel reproductive polymorphism in the Pacific field cricket.

Associations between heritable polymorphisms and life-history traits, such as development time or reproductive investment, may play an underappreciated role in maintaining polymorphic systems. This is because selection acting on a particular morph could be bolstered or disrupted by correlated changes in life history or vice versa. In a Hawaiian population of the Pacific field cricket (Teleogryllus oceanicus), a novel mutation (flatwing) on the X-chromosome is responsible for a heritable polymorphism in male wing structure. We used laboratory cricket colonies fixed for male wing morph to investigate whether males and females bearing the flatwing or normal-wing (wild-type) allele differed in their life-history traits. We found that flatwing males developed faster and had heavier testes than normal-wings, whereas flatwing homozygous females developed slower and had lighter reproductive tissues than normal-wing homozygous females. Our results advance our understanding of the evolution of polymorphisms by demonstrating that the genetic change responsible for a reproductive polymorphism can also have consequences for fundamental life-history traits in both males and females.

Random forests for predicting species identity of forensically important blow flies (Diptera: Calliphoridae) and flesh flies (Diptera: Sarcophagidae) using geometric morphometric data: Proof of concept.

Wing shape variation has been shown to be useful for delineating forensically important fly species in two Diptera families: Calliphoridae and Sarcophagidae. Compared to DNA-based identification, the cost of geometric morphometric data acquisition and analysis is relatively much lower because the tools required are basic, and stable softwares are available. However, to date, an explicit demonstration of using wing geometric morphometric data for species identity prediction in these two families remains lacking. Here, geometric morphometric data from 19 homologous landmarks on the left wing of males from seven species of Calliphoridae (n=55), and eight species of Sarcophagidae (n=40) were obtained and processed using Generalized Procrustes Analysis. Allometric effect was removed by regressing centroid size (in log10 ) against the Procrustes coordinates. Subsequently, principal component analysis of the allometry-adjusted Procrustes variables was done, with the first 15 principal components used to train a random forests model for species prediction. Using a real test sample consisting of 33 male fly specimens collected around a human corpse at a crime scene, the estimated percentage of concordance between species identities predicted using the random forests model and those inferred using DNA-based identification was about 80.6% (approximate 95% confidence interval=[68.9%, 92.2%]). In contrast, baseline concordance using naive majority class prediction was 36.4%. The results provide proof of concept that geometric morphometric data has good potential to complement morphological and DNA-based identification of blow flies and flesh flies in forensic work.

Specialized androconial scales conceal species-specific semiochemicals of sympatric sulphur butterflies (Lepidoptera: Pieridae: Coliadinae)

Chemical cues play an important role in short-range communication of butterflies, remarkably in sexual attraction and mate choice. Differentiated scale patches on the wings of male butterflies, the androconia, are involved in the emission of pheromones. Here, we describe the androconial morphology of six sympatric species of Neotropical sulphur butterflies belonging to two genera of the Colias-clade (Pieridae) based on SEM imaging. Gas chromatography-mass spectrometry analyses were used to access the chemical compositions of androconial secretions, which were comparatively investigated to determine species-specific trends and to verify if they yield a phylogenetic signal. The androconial patches from all species are differentiated from the non-androconial male wing surface and exhibit morphological features that may act in both preventing the volatilization of secretions and facilitating the release of semiochemicals, such as high density and length of scales and large perforations in the upper lamellae. A total of 55 compounds were exclusive to the androconia, and unique chemical profiles are present in each butterfly species, verified through multivariate analysis. The majority of androconial compounds were autapomorphic for each species and only four were dominant in more than one species. Cluster analyses placed the two species of Anteos in a single clade, but otherwise evidenced low similarities in the androconial secretion compositions among species, and a moderate correlation between genetic distances and chemical dissimilarities was obtained. Our findings suggest that androconial substances are involved in mating-oriented strategies and might be associated with the evolutionary history of the reproductive isolation of sulphurs.

Studies of Myc super-competition and clonal growth in Drosophila males and females.

Cell competition is a cell selection process that arises in growing tissues as a result of interactions between cells of different fitness. This behavior is also observed in Myc super-competition, where healthy wild type cells in growing wing discs of Drosophila are outcompeted by nearby cells that express higher levels of the Myc oncogene. Most work on Myc super-competition has examined it in mixed populations of male and female larvae. However, as physiological and genetic differences between Drosophila males and females could affect the competitive behavior of cells, we have investigated whether sex differences affect the process. Here we show that both male and female wing disc cells are subject to Myc super-competition. Female disc cells appear to be more sensitive to competitive elimination than male cells, potentially due to differences in baseline cellular Myc levels between the sexes. We also report sexual dimorphism of cell size and number between male and female growing wing discs that is independent of competition; wing discs and wing pouches from females are larger than males’ due to larger cell size and cell number. We suggest that separately examining male and female tissues in cell competition assays could enhance our understanding of the effects of sex-specific pathways on cell and super-competition.

A scientometric analysis on pre- and post-copulatory traits in Odonata

In the last decades, studies on sexual selection in odonates have shown a relationship between mating success and costly sexual ornaments, mainly male characters. Here, we conducted a scientometric analysis to assess the state of art of studies on sexual selection in odonates, especially on the role of male ornamentation (pre-copulatory traits) and sperm competition (post-copulatory traits). We found 51 papers focused on sexual ornamentation and 34 on sperm competition. Only one study simultaneously addressed both pre- and post-copulatory traits, nevertheless without an integrative approach. Results show that calopterygids are extensively studied regarding pre-copulatory traits (i.e., male wing pigmentation), while libellulids are mostly studied in post- copulatory traits (e.g., sperm competition) focused research. These preferences seem to be related to characteristics like presence of ornamentation and territoriality, large body size, variation and complexity of sperm removal structures, respectively. For the post-copulatory traits, sperm removal is frequently addressed, but few other strategies, like the investment in sperm quality and quantity, are investigated. Finally, we demonstrate that it is necessary to conduct studies focused on addressing the relationship between pre- and post- mating sexual traits.

A new species of Carpenter Moths (Lepidoptera, Cossidae) from Tarbagatai (NE Kazakhstan) and Altai (SW Siberia, Russia) Mountains.

We described a new cossid species, Dyspessa ulgen sp. nov. from the Tarbagatai and Altai Mountains and compared it to other taxa of Dyspessa reported from the region (D. tristis, D. saldaitisi, D. saissanica), as well as to morphologically similar D. ulula. The new species is most closely related to D. ulula but differs from the latter in the characteristics of the male genitalia, wing pattern, and molecular data (a 658 bp fragment of the mitochondrial COI gene).

Different diets can affect attractiveness of Drosophila melanogaster males via changes in wing morphology

Courtship in Drosophila involves exchange of chemosensory, auditory, tactile and visual signals. Differences in courtship signals are strongly influenced by environmental factors, among which nutrition plays one of the more important roles. Through influence on development, morphology, physiology and behaviour, nutrition may affect both sexual selection and isolation. However, the impact of specific nutritive regimes on male mating success has not been extensively studied. Therefore, the aim of this study was to explore how diets affect male attractiveness via changes in wing morphology during long-term rearing of flies on different diets. Through a series of female choice tests, we investigated the mating success of males reared on five different diets for more than 350 generations. Further, we analysed wing size and wing shape of mated and unmated males to link wing morphology with mating success. The results demonstrate significant differences in male mating success between strains. We also found significant differences in wing size between the strains and established that female choice is positively correlated with male wing size, that is, females of all strains preferred males with larger wings. In addition, we noted a significant difference in wing shape between the strains, as well as between mated and unmated males. Our results indicated that among strains, males with elongated wings were more successful in mating than males with rounded wings. Within strains, mated males had more elongated wings than unmated ones, which had more rounded wings. Our results support the hypothesis that nutrition represents an important environmental factor that may affect male attractiveness via changes in wing morphology, thereby playing an important role in sexual selection of Drosophila melanogaster . • Male mating success of Drosophila is related to wing size and shape. • Wing morphology in D. melanogaster may depend on diet. • In this study, we used flies reared for 350 generations on different diets. • Larger males reared on a tomato diet had the highest mating success. • Males with elongated wings had higher mating success than those with rounded wings.

Hox genes are essential for the development of eyespots in Bicyclus anynana butterflies.

The eyespot patterns found on the wings of nymphalid butterflies are novel traits that originated first in hindwings and subsequently in forewings, suggesting that eyespot development might be dependent on Hox genes. Hindwings differ from forewings in the expression of Ultrabithorax (Ubx), but the function of this Hox gene in eyespot development as well as that of another Hox gene Antennapedia (Antp), expressed specifically in eyespots centers on both wings, are still unclear. We used CRISPR-Cas9 to target both genes in Bicyclus anynana butterflies. We show that Antp is essential for eyespot development on the forewings and for the differentiation of white centers and larger eyespots on hindwings, whereas Ubx is essential not only for the development of at least some hindwing eyespots but also for repressing the size of other eyespots. Additionally, Antp is essential for the development of silver scales in male wings. In summary, Antp and Ubx, in addition to their conserved roles in modifying serially homologous segments along the anterior-posterior axis of insects, have acquired a novel role in promoting the development of a new set of serial homologs, the eyespot patterns, in both forewings (Antp) and hindwings (Antp and Ubx) of B. anynana butterflies. We propose that the peculiar pattern of eyespot origins on hindwings first, followed by forewings, could be due to an initial co-option of Ubx into eyespot development followed by a later, partially redundant, co-option of Antp into the same network.

Rapid colour shift by reproductive character displacement in Cupido butterflies.

Reproductive character displacement occurs when competition for successful breeding imposes a divergent selection on the interacting species, causing a divergence of reproductive traits. Here, we show that a disputed butterfly taxon is actually a case of male wing colour shift, apparently produced by reproductive character displacement. Using double digest restriction-site associated DNA sequencing and mitochondrial DNA sequencing we studied four butterfly taxa of the subgenus Cupido (Lepidoptera: Lycaenidae): Cupido minimus and the taxon carswelli, both characterized by brown males and females, plus C. lorquinii and C. osiris, both with blue males and brown females. Unexpectedly, taxa carswelli and C. lorquinii were close to indistinguishable based on our genomic and mitochondrial data, despite displaying strikingly different male coloration. In addition, we report and analysed a brown male within the C. lorquinii range, which demonstrates that the brown morph occurs at very low frequency in C. lorquinii. Such evidence strongly suggests that carswelli is conspecific with C. lorquinii and represents populations with a fixed male brown colour morph. Considering that these brown populations occur in sympatry with or very close to the blue C. osiris, and that the blue C. lorquinii populations never do, we propose that the taxon carswelli could have lost the blue colour due to reproductive character displacement with C. osiris. Since male colour is important for conspecific recognition during courtship, we hypothesize that the observed colour shift may eventually trigger incipient speciation between blue and brown populations. Male colour seems to be an evolutionarily labile character in the Polyommatinae, and the mechanism described here might be at work in the wide diversification of this subfamily of butterflies.