Search

The odonates are insects that have a wide range of reproductive, ritualized territorial, and aggressive behaviors. Changes in behavior are the first response of most odonate species to environmental alterations. In this context, the primary objective of the present study was to assess the effects of environmental alterations resulting from shifts in land use on different aspects of the behavioral diversity of adult odonates. Fieldwork was conducted at 92 low-order streams in two different regions of the Brazilian Amazon. To address our main objective, we measured 29 abiotic variables at each stream, together with five morphological and five behavioral traits of the resident odonates. The results indicate a loss of behaviors at sites impacted by anthropogenic changes, as well as variation in some morphological/behavioral traits under specific environmental conditions. We highlight the importance of considering behavioral traits in the development of conservation strategies, given that species with a unique behavioral repertoire may suffer specific types of extinction pressure. Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brasil | Ref. 449315 / 2014-2 Conselho Nacional de Desenvolvimento Científico e Tecnológico , Brasil | Ref. 481015 / 2011-6 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brasil | Ref. 88887.493682 / 2020-00 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brasil | Ref. 88887.469089 / 2019 Conselho Nacional de Desenvolvimento Científico e Tecnológico , Brasil | Ref. 304710 / 2019-9 Conselho Nacional de Desenvolvimento Científico e Tecnológico , Brasil | Ref. 307836 / 2019-3 Conselho Nacional de Desenvolvimento Científico e Tecnológico , Brasil | Ref. 141991 / 2016-0 Conselho Nacional de Desenvolvimento Científico e Tecnológico , Brasil | Ref. 141113 / 2020-0 Conselho Nacional de Desenvolvimento Científico e Tecnológico , Brasil | Ref. 154761 / 2018-4 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brasil | Ref. 88881.474457 / 2020-01 FAPESP - Fundação de Amparo à Pesquisa do Estado de São Paulo. | Ref. 2013 / 00406-7 FAPESP - Fundação de Amparo à Pesquisa do Estado de São Paulo | Ref. 2019 / 20130-2 Ministerio de Ciencia, España | Ref. CGL2014-53140-P Ministerio de Ciencia, España | Ref. PGC2018-096656-B-I00

Human activities have facilitated the introduction of invasive plants worldwide, altering habitat structure and leading to substantial effects on biodiversity. However, the effects of plant invasions on herbivore communities are understudied. Here, we examine factors influencing the occurrence of herbivores in ten coastal sites invaded by Carpobrotus edulis in the northwestern Iberian Peninsula. The aims were to evaluate the distribution and abundance of herbivorous invertebrates in different communities (invaded vs. non-invaded), explore the structure of plant–herbivore interaction networks, and assess whether the presence of herbivores affects the performance and fitness of C. edulis. Our results show that herbivore species composition was altered by the presence of C. edulis. Non-invaded plots had a higher number of plant–herbivore interactions and more specialized herbivore species, resulting in a greater degree of specialization. We also found an increase in the number of damaged flowers (florivory) of C. edulis by the native snails Theba pisana and Cornu aspersum. We conclude that C. edulis alters herbivore communities compared with non-invaded plots by changing plant–herbivore interactions and increasing the abundance of herbivores in invaded coastal sites. Snails might reduce seed production of C. edulis, acting as a natural biological control agent. Understanding the impacts of introduced species over invertebrate species at different community levels is crucial for implementing long-term management strategies that are key to reducing the impact of C. edulis on biodiversity.

Forests have been widely recognized as key habitats for odonate (dragonflies and damselflies) biodiversity, but the importance of forests for holding odonate biodiversity remains understudied in tropical mountains, one of the most diverse ecosystems on the planet. Here we described the odonate assemblage composition along the elevation gradient in the Tatamá Mountains (Colombian Cordillera Occidental). We analyzed the effects of elevation, habitat, and suborder on species richness and endemism. We found that the richest assemblage occurred in the foothills between 300 and 600 m, where the biotas of the Chocó biogeographic region and the Tropical Andes converge. Anisoptera richness was higher in open-habitat habitats, that of Zygoptera higher in forests. Richness and endemism decreased with elevation, and no relation between habitat and richness was found. However, the number of endemic species was strongly related to forests, which harbored 25 out of 28 endemic species. Also, forest odonates had narrower elevation ranges than open-habitat odonates. These patterns can be explained because tropical mountains were historically covered by forests, while open habitats derived from human activities (i.e., pastures) have flourished in the past centuries. The forest odonate assemblages at different elevations have been evolving for millions of years, in relatively stable ecological conditions, which could promote the high number of forest endemics in the tropical mountains. Our results emphasize the role of tropical mountain forests in the conservation of Odonata diversity.

Demography and territorial behavior of Hetaerina cruentata was studied along three lowland streams located at Norte de Santander department in the Colombian Andean region. Adult damselflies (N: 278) were individually marked, and using their recapture histories we estimated survival, longevity, sex ratio, age groups and population size at each location. We found no evidence for survival differences between ages and sexes. However, the proportion of resighted individuals was lower for females, and the sex ratio was male-biased in all populations. Although we recorded few reproductive events, a high number of male-male agonistic interactions were registered around midday. During reproductive behavior, we observed brief wing displays as signals between males and females, and the formation of the tandem position, followed by the intra-male sperm translocation and copulation (mean duration 11.3 min). After copulation, the pair in tandem looked for suitable sites to oviposit, and then the male broke tandem and perched on the vegetation while the female laid eggs partially or completely underwater. The recapture probability was time-dependent, which suggests that the alternation of rainy and sunny days during the study may be generating differences in the demography of the three H. cruentata populations.

Understanding the life cycle of Neotropical odonate species is essential given our scant knowledge of this region. In this paper, we examine growth ratio between instars, development patterns, and active/passive feeding behavior of the Andean dragonfly Erythrodiplax abjecta ( Rambur, 1842 ). Larvae were obtained from eggs laid by two females in the laboratory and were maintained at 12–34 °C in individual containers until either their emergence or their death. Larvae hatched 26–57 days after laying, and the total development time was determined as being 316 (SD ± 6.6) days, including 13 instars. Larval instars were characterized using six morphometric variables. The foraging behavior was analyzed considering the time of day and the percentage of the background covered by detritus. The growth ratios between successive instars averaged 1.9 for FW pad length, 1.6 for HW pad length and 1.2 for head width, head length, metathoracic leg length, and total length. Neither the active foraging nor the sit-and-wait foraging behavior were affected by either time of the day or the percentage of background covered by detritus. Erythrodiplax abjecta is univoltine and has a slow lifestyle associated with lentic perennial waters, where larval development and growth rates are low. We provide an equation to estimate the E. abjecta larval instars from field specimens. Given that our results were obtained from the eggs laid by only two females, further studies including a larger sample size are needed to validate their generality.

Insects are reportedly experiencing widespread declines, but we generally have sparse data on their abundance. Correcting this shortfall will take more effort than professional entomologists alone can manage. Volunteer nature enthusiasts can greatly help to monitor the abundance of dragonflies and damselflies (Odonata), iconic freshwater sentinels and one of the few nonpollinator insect groups appreciated by the public and amenable to citizen science. Although counting individual odonates is common in some locations, current data will not enable a global perspective on odonate abundance patterns and trends. Borrowing insight from butterfly monitoring efforts, we outline basic plans for a global volunteer network to count odonates, including organizational structure, advertising and recruiting, and data collection, submission, and synthesis. We hope our proposal serves as a catalyst for richer coordinated efforts to understand population trends of odonates and other insects in the Anthropocene.

Simple Summary Flying insects are able to colonize oceanic islands by both active and passive dispersal. Ten species of dragonflies are found in the Galapagos archipelago, located at 900 km from mainland South America. Shortly after the publication of Darwin’s “The Origin of Species”, one of the dragonflies from these islands was named after him as Tramea darwini. However, subsequent studies considered it to belong to another continental species of the same genus known as Tramea cophysa. Here, we studied a series of specimens of Tramea collected in 2018 from the Islands of San Cristobal, Isabela, and Santa Cruz, with the aim of determining their specific identity, through a combination of molecular and morphological analyses. Our results indicate that the Galapagos specimens examined belong to Tramea calverti, another continental species, and not to T. cophysa as previously thought. Following the principle of priority in taxonomic nomenclature, Tramea calverti, which was described in 1910 by Muttkowski, should hereafter be considered a synonym of Tramea darwini, which was described in 1889 by Kirby; hence, the species named after Darwin is to be considered valid, inhabiting both the Galapagos islands and continental America. Abstract The status of the Tramea species present in the Galapagos Islands (Odonata, Libellulidae) has been the subject of a long-standing debate among odonatologists. Here, we use molecular and morphological data to analyze a series of specimens from this genus collected in 2018 from the Islands of San Cristobal, Isabela, and Santa Cruz, with the aim of determining their relationship with Tramea calverti Muttkowski and with their currently considered senior synonym T. cophysa Hagen. We combined sequencing of mitochondrial and nuclear DNA with morphological examination of several specimens of Tramea, including representatives of continental T. cophysa and T. calverti. Our molecular analyses place the Tramea from Galapagos in the same clade as T. calverti, with T. cophysa as a closely related species. The morphological analyses found only one consistent difference between T. cophysa and T. calverti: the presence of an accessory lobe in the male vesica spermalis of T. cophysa that is absent in T. calverti and in the Tramea from Galapagos. In agreement with our genetic results, the overall morphological differences documented by us indicate that the Galapagos material examined is conspecific with T. calverti. In light of this, and following the principle of priority in taxonomic nomenclature, Tramea calverti Muttkowski, 1910 should hereafter be considered a junior synonym of Tramea darwini Kirby, 1889.

Plant invasions can modify the composition of native communities through altering diversity and ecosystem functioning. For example, arthropod communities can be influenced by the introduction of invasive plant species, but the impacts of plant invasions on arthropod communities have received little attention. Here, we investigated the diversity and species composition of arthropods in areas with and without invasive plants by comparing native ecosystems and areas invaded by Acacia dealbata, A. longifolia and A. melanoxylon in 18 locations in the northwestern Iberian Peninsula. Yellow sticky traps were placed in branches above ground in randomly selected areas and used to qualify and quantify the number of aerial arthropods. The aim was to assess the impact of invasive Acacia on arthropod species in different ecosystems. Our results demonstrate that arthropods are negatively influenced by Acacia invasions, reducing the abundance and diversity in invaded areas, which had substantial effects on beta-diversity and trophic levels. Overall, our findings indicate that invasive acacias can alter the species composition by not only reducing abundance and diversity but also altering the different trophic groups of the arthropod assemblages. The physical dominance of Acacia invaders alters the co-occurrence of arthropod assemblages, reducing the number of groups and leading to substantial effects on ecosystem dynamics as well as in the trophic diversity. We suggest implementing management strategies to favour the protection of native ecosystems and reduce the impacts of these exotic plants on arthropod biodiversity at the habitat level.

Sperm quality and viability affect both male and female fitness. Most dragonfly and damselfly males translocate sperm from the testis to the seminal vesicle before each copulation, a behaviour known as intramale sperm translocation (ST). However, some published observations indicate that odonate males can occasionally skip ST prior to copulation. Our aim was to determine the circumstances under which males skip ST and how this might affect sperm viability. We allowed males of the damselfly Ischnura graellsii to perform ST (interrupting the copulation at this stage) and we studied ST behaviour during subsequent copulation. Males were randomly assigned to four treatments, which consisted of allowing the experimental male to copulate again 15 min or 1–3 days after his last ST. Fertility of females mated with the experimental males was analysed as a proxy for sperm viability. All males used the sperm that they translocated previously when the second mating took place 15 min after the manipulation, while the proportion of males that repeated ST increased steadily over time. Both treatment (time elapsed since last ST) and the interaction between treatment and ST (yes/no) had a significant effect on fertility, which decreased only in males that did not perform ST immediately before copulation. Additional experiments with damselflies of the genus Calopteryx showed also that males did not repeat ST when the time to the next copulation was less than a day. Our results suggest that sperm quality decays over time in odonates, and that males can choose whether to keep and reuse the sperm in the seminal vesicle or to discard it. We conclude that the special anatomical disposition of odonate males might increase selective pressures to maximize sperm viability and/or repeated intramale ST behaviour.

Several species of biting midges of the genus Forcipomyia are frequently found attached to the wings of adult odonates, acting as parasites by sucking haemolymph from the wing veins. Here we report the first finding of F. incubans on odonates in the peninsula of Zapata, Cuba. We found the midge on the wings of Erythrodiplax simplicicollis, E. umbrata, Crocothemis servilia, and in the wings and body of Perithemis domitia, all species belonging to the family Libellulidae. This is the first record of this interaction for the Antilles.

The ‘functional allometry’ hypothesis proposes that the variation in allometric patterns of sexually selected traits is related to their function. We hypothesize that the allometric patterns for genitalia of aggressively territorial organisms are different from those in non-territorial organisms and predict that in aggressively territorial species, where body size is related directly to reproductive success, males must allocate more resources to body size than to genitalia. We studied 59 species of damselflies in 51 genera. Species were divided into three categories: highly territorial and aggressive; low aggressive; and not aggressive. We measured the length of the genital ligula, the width at the basis and its maximum width, and we used body length and wing length as descriptors of body size. The slope of allometric relationships was estimated using ordinary least squares and reduced major axis regressions. Our results indicated first, that territorial damselflies are larger and that body length and wing length are not equivalent as estimators of body size in odonates. Second, ordinary least squares and reduced major axis regressions provided different results in some of the analyses. Third, we found that aggressive species have less steep allometric slopes than non-aggressive species, both for the length of the ligula and for the width at its basis. Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG Ministerio de Ciencia e Innovación | CGL2008-02799 Ministerio de Ciencia e Innovación | Ref. CGL2005-00122 Ministerio de Ciencia e Innovación | Ref. PCI2006-A7-0639 Ministerio de Ciencia e Innovación | Ref. CGL2008-02799 Ministerio de Ciencia e Innovación | Ref. CGL2011-22629 Ministerio de Economía y Competitividad | Ref. CGL2014-53140-P Agencia Estatal de Investigación | Ref. PGC2018-096656-B-I00

Dragonflies and damselflies are a charismatic, medium-sized insect order (~6300 species) with a unique potential to approach comparative research questions. Their taxonomy and many ecological traits for a large fraction of extant species are relatively well understood. However, until now, the lack of a large-scale phylogeny based on high throughput data with the potential to connect both perspectives has precluded comparative evolutionary questions for these insects. Here, we provide an ordinal hypothesis of classification based on anchored hybrid enrichment using a total of 136 species representing 46 of the 48 families or incertae sedis, and a total of 478 target loci. Our analyses recovered the monophyly for all three suborders: Anisoptera, Anisozygoptera and Zygoptera. Although the backbone of the topology was reinforced and showed the highest support values to date, our genomic data was unable to stronglyresolve portions of the topology. In addition, a quartet sampling approach highlights the potential evolutionary scenarios that may have shaped evolutionary phylogeny (e.g., incomplete lineage sorting and introgression) of this taxon. Finally, in light of our phylogenomic reconstruction and previous morphological and molecular information we proposed an updated odonate classification and define five new families (Amanipodagrionidae fam. nov., Mesagrionidae fam. nov., Mesopodagrionidae fam. nov., Priscagrionidae fam. nov., Protolestidae fam. nov.) and reinstate another two (Rhipidolestidae stat. res., Tatocnemididae stat. res.). Additionally, we feature the problematic taxonomic groupings for examination in future studies to improve our current phylogenetic hypothesis National Science Foundation | Ref. DEB-1265714 National Science Foundation | Ref. DBI-1564386 Ministerio de Ciencia | Ref. CGL2014-53140-P Ministerio de Ciencia | Ref. PGC2018-096656-B-I00

Dragonflies and damselflies have become model organisms in ecological and evolutionary studies, mainly because they are considered flagship taxa for the conservation of water resources. Hence, how to standardize collection of odonates for the assessment of their diversity is an issue most researchers working with the group or the ecology of freshwaters may face. We aim at presenting sampling protocols that may aid researchers that are interested in sampling adults, exuviae, and larvae of Odonata. These three life phases have different detectabilities, and we propose that should be combined wherever possible.

The efficiency of local augmentation releases of the egg parasitoid Anaphes nitens to control the Eucalyptus snout‐beetle Gonipterus platensis was tested in Eucalyptus globulus plantations in Galicia (NW Spain). On May–June 2006, at two localities of Pontevedra province, the release of host egg capsules parasitized by A. nitens at a potential rate of 300 adults/ha was compared with a release density of 900 adults/ha, and a control group of eucalypts not subjected to augmentation. Parasitism rate after 1–2 weeks did not significantly increase over the control plots at both localities. The high release rate did not ensure a higher crop protection and therefore could be not economically justified. On March–April 2017, at four localities of Pontevedra province, the test was replicated by releasing 300 parasitoids/ha. Parasitism level did significantly increase over the control just in one locality. Augmentation of A. nitens at small scale generally failed to achieve a higher protection from the pest, possibly due to the large extension of the E. globulus plantations, the magnitude of the G. platensis population and the fluctuations of the established parasitoid population, whose density is in turn affected by host egg availability and density‐dependent dispersal.

Invasive alien plant species have become dominant components of many landscapes, where they are indicators of ecological disequilibria. They coexist and compete with native plants, disrupting a wide range of trophic interactions, and must cope with a new array of herbivores. We examined factors influencing the occurrence of invertebrate herbivores on two invasive alien plant species, Acacia dealbata and Carpobrotus edulis, and surrounding native vegetation in the northwestern Iberian Peninsula. The aims were to assess the accumulation of herbivorous insects, including the distribution and frequency of herbivorous insects at different invasion levels (low, medium and high), and to evaluate whether introduced plants favour native or exotic, and generalist or specialist herbivorous insects in newly evolving plant–herbivore networks. To achieve these objectives, we surveyed A. dealbata along transects in five mixed pine forests and four shrublands, and C. edulis in nine coastal areas using quadrats. We identified nine herbivore species feeding on one or both of these species and determined that herbivore species composition in forest and coastal areas is directly tied to host preference, as well as related to invasion levels of A. dealbata in forest areas. On average, the introduced species in both the forest and coastal areas had approximately threefold more herbivore species (~ 50% of them exotics) than native plants. The introduced plants in forest areas had approximately eightfold more species interaction strength between herbivores and plants (a measure of the importance of each plant species to each herbivore). Overall, generalist herbivores were favoured by the invasion of the introduced plants. The results also demonstrate that exotic insects are supported by introduced plants, increasing the local occurrence and range of insect pests. Considering our observations, management strategies should be implemented to favour the restoration and protection of native areas for conserving biodiversity.

We studied parasitism rate by the terrestrial mite Leptus killingtoni Turk (Acari: Erythraeidae) on asexual parthenogenetic damselflies, Ischnura hastata (Say), and sexual Ischnura pumilio (Charpentier) (Odonata: Coenagrionidae) on Pico island (Azores, Portugal). We sampled 52 water bodies on the island and recorded whether Ischnura specimens were parasitized. Half of the water bodies had either dried up or were almost dry or did not have Ischnura populations. In the remaining 23 ponds, mite parasitism was extremely low, with only 3.6% of I. hastata females bearing one or more mites. Ischnura pumilio was rare on the island (61 specimens examined) and had also very few parasites (9.8% parasitism). We examined the biology of the mite and its effects on the host, by studying mite attachment behavior and seasonal abundance, in an intensive study of one pond (Lagoa do Landroal). At this pond, mite prevalence peaked at the start of the sampling period, with 32% of females of I. hastata parasitized and decreased continuously until the end of the study, when only 2% were parasitized. The analysis of mark–recapture histories of 1 748 females of I. hastata indicates that mites did not affect female survival or recapture rate. Our results suggest that L. killingtoni is unlikely to represent a significant selective factor for odonates on the island of Pico, if its density is as low as during the period of our study, although it could be relevant when it is locally abundant or during periods of outbreak.

Many species are currently changing their distributions and subsequently form sympatric zones with hybridization between formerly allopatric species as one possible consequence. The damselfly Ischnura elegans has recently expanded south into the range of its ecologically and morphologically similar sister species Ischnura graellsii. Molecular work shows ongoing introgression between these species, but the extent to which this species mixing is modulated by ecological niche use is not known. Here, we (1) conduct a detailed population genetic analysis based on molecular markers and (2) model the ecological niche use of both species in allopatric and sympatric regions. Population genetic analyses showed chronic introgression between I. elegans and I. graellsii across a wide part of Spain, and admixture analysis corroborated this, showing that the majority of I. elegans from the sympatric zone could not be assigned to either the I. elegans or I. graellsii species cluster. Niche modeling demonstrated that I. elegans has modified its environmental niche following hybridization and genetic introgression with I. graellsii, making niche space of introgressed I. elegans populations more similar to I. graellsii. Taken together, this corroborates the view that adaptive introgression has moved genes from I. graellsii into I. elegans and that this process is enabling Spanish I. elegans to occupy a novel niche, further facilitating its expansion. Our results add to the growing evidence that hybridization can play an important and creative role in the adaptive evolution of animals.

Phenotypic divergence can occur through both local adaptations and phenotypic plasticity in response to particular environmental pressures. Holocene land-bridge islands harbor recent isolated populations that offer an excellent natural framework to study the microevolutionary processes involved in rapid or ongoing phenotypic shifts. Two insular populations (Ons and San Martino) of Salamandra salamandra in NW Iberian Peninsula exemplify these phenotypic shifts with a rapid evolutionary transition in reproductive mode and genetic differentiation since their isolation ca. 8000 years ago. We evaluate parallel phenotypic changes in body size and behavior. In particular, we (1) collected observational fieldwork data during diurnal and nocturnal transects in both islands for over a decade (2004–2016); (2) investigated the climatic conditions associated to fire salamanders’ activity; (3) compared physical condition between insular and mainland populations; and (4) used plasticine models and camera trapping to identify potential predators that might cause the observed diurnal activity in San Martino Island. Our 13-year-long study shows that salamanders from San Martino show mainly diurnal activity and are significantly smaller than salamanders from Ons and nearby continental populations. Overall, we present an exceptional case of behavior and phenotypic differentiation of an insular population of fire salamanders and suggest that this unusual behavior in the small population of San Martino might be triggered by a response to predator pressure exerted by a dense population of Rattus rattus.

Damselflies adapted to forest habitats are expected to be negatively affected by the disturbance of riparian forests, due to the change in insolation when trees are cleared. In this paper, we compare survivorship and behaviour of two populations of Heteragrion cooki by means of mark-recapture methods and focal observations of adults. We found similar densities of males (but not of females) in both streams, and similar recapture rates, higher for males (50%) than for females (20%). Body size was also significantly different between populations, with smaller individuals in the shadiest stream. The analysis of daily survival rates indicated that in the shaded stream, males survived better than females, whereas in the sunnier stream survival was similar between sexes, but varied over time. Furthermore, in the sunny stream, body size was negatively correlated with survival. Males arrived earlier than females to the stream, with a maximum activity between 13 and 16 hours. They defended small patches of the stream, exhibiting high site fidelity and aggressive behaviour against conspecific males. Copulation, which was very rarely seen in the stream, lasted about six minutes. Pairs in tandem remained for an average of 45 minutes laying eggs on roots and lianas. We found that H. cooki was not drastically affected by the loss of riparian vegetation, maintaining similar densities of males in both streams, probably because small remnants of native forests were still found near to the stream.

Plant invasions impact on biodiversity by altering the composition of native communities by disrupting taxonomic and functional diversity. Non-native plants are often released from their natural enemies, which might result in a reduction of the attack of primary consumers. However, they can also be exposed to the attack of new herbivores that they might not be able to tolerate. Hence, invertebrate communities can be influenced by invasive non-native plants, which in turn modify interactions and change environmental conditions. In this study, we examined the compositional and trophic diversity of invertebrate species, comparing ecosystems with and without the plant species Carpobrotus edulis in coastal areas in its native (South Africa) and introduced (Iberian Peninsula) ranges. Results show that C. edulis has a clear impact on invertebrate communities in its non-native range, reducing their abundance in invaded areas, and particularly affecting certain trophic groups. Invasive C. edulis also alters the invertebrate diversity by not only reducing abundance but also by altering species composition. Overall, the physical dominance of C. edulis modifies the co-occurrence of invertebrate assemblages, reducing the number of trophic groups and leading to substantial effects on primary consumers. Results suggest that the lack of natural enemies might be an important driver of the expansion of C. edulis in its introduced range. Further work is needed to examine long-term changes caused by non-native plants on invertebrate assemblages and the subsequent modification of biological interactions. Xunta de Galicia. (CITACA Strategic Partnership, Ref: ED431E 2018/07) Ministerio de Economía y Competitividad, Ref. CGL2013-48885-C2-1-R Xunta de Galicia/FEDER, Ref. (GRC2015/012) Consellería de Educación y Ordenación Universitaria Universidade de Vigo Czech Science Foundation (Project No. 19-13142S) Czech Science Foundation (EXPRO grant no. 19-28807X) Czech Academy of Sciences (nº. RVO 67985939) DSINRF Centre of Excellence for Invasion Biology DSINRF Centre of Excellence for Invasion Biology (grant 85417) South African Department of Environment, Forestry, and Fisheries (DEFF)

Philogenia gaiae sp. nov. (Holotype ♂, Ecuador, Orellana, Tiputini Biodiversity Station, -0.6349, -76.1501, 241 m, 13 xii 2012, A. Cordero-Rivera & M. Sánchez-Herrera leg., in MUAE) from the helena group is described, illustrated, diagnosed and compared with morphologically close species of the genus. Philogenia gaiae can be distinguished from its most similar congener P. minteri Dunkle, 1986 by the enlarged cerci and the club-like paraprocts. We also describe the female of P. macuma Dunkle, 1986, from a pair collected at Jatún Sacha Biological Reserve, which is also similar to P. gaiae and can be distinguished by the intersternite morphology, ovipositor length and vulvar lamina shape.

Behavioural diversity is a basic component of biodiversity, with implications in ecological interactions at the intra- and interspecific levels. The reproductive behaviour of Odonata (dragonflies and damselflies) is unique among insects and conditioned by the anatomical separation between the male’s reproductive organs and the intromittent organ. Prior to mating, males must translocate sperm from the genital pore in the ninth abdominal segment to the seminal vesicle located ventrally in the second abdominal segment. This behaviour, exclusive to odonates, is known as intra-male sperm translocation (ST). Here, we review the literature on ST and use phylogenetic comparative analyses to investigate the evolution of ST within the Odonata. Information on ST was compiled for 176 species, with the commonest variant being ST once per mating, after tandem formation (66%). Other variants found were ST involving precopulatory genital touching (10%), ST by the male alone before tandem (16%) or after copulation (5%), and repetition of ST during the same copulation (3%). The precopulatory genital touching might have evolved to detect female receptivity. ST before tandem formation might be favoured when mating opportunities are scarce and copulations are brief. ST after mating might be favoured if males need to be ready to copulate fast. Finally, repeated ST could have evolved through postcopulatory sexual selection in males with limited sperm removal ability, as a means to improve their sperm competition. The most plausible scenario for the evolution of ST is that the ancestors of the Odonata produced a spermatophore and attached it to the body, leading towards the evolution of the secondary genitalia in males. Our study emphasises the role of behavioural diversity to understand behavioural evolution. Unique behaviours are exclusive of a few individuals, populations and/or species. The intra-male sperm translocation (ST) of dragonflies and damselflies is a unique behaviour in animals: before mating, males need to transfer sperm from the primary to the secondary genitalia, which are anatomically separated. Thus, the viability and quality of sperm (i.e. fertility) will depend on the timing of ST relative to copulation. Our literature review found a variety of ST variants, being ST in tandem and before copulation the ancestral strategy. We discuss putative evolutionary routes for all the variants found and emphasise the importance of retrieving detailed observations of such unique behaviours in the field, which could help to better understand behavioural evolution in this insect group. Behavioural diversity is rarely addressed by conservation strategies, despite unique behaviours being at a higher risk of extinction.

The female of Heteragrion icterops Selys, 1862, incompletely mentioned in 1886, is described, illustrated, keyed and diagnosed based on specimens collected in Pará State, North Brazil. We also provide an identification key and diagnostic comments on other two Group B females occurring in Brazil: H. angustipenne Selys, 1886 and H. bariai De Marmels, 1989. Heteragrion icterops females can be distinguished from other female congeners by having the genital valves tips leveling the posterior margin of S10 and by the morphology of the intersternites, presenting a well-developed dorsal plate and lacking a posterior plate.

Species classification may not reflect the underlying/cryptic genetic diversity which should otherwise be conserved as it represents the potential of populations to evolve and adapt. The identification of evolutionarily significant units (ESUs) allows cryptic genetic diversity to be taken into account when designating conservation priorities. Here, we used mitochondrial and nuclear DNA sequences integrated with ecological niche models (ENM) to identify ESUs in Hypolestes trinitatis, a threatened Cuban endemic damselfly species. We found that this species comprises two distinct genetic groups in Central and Eastern Cuba respectively, which are also geographically isolated, as shown by ENM. Therefore, we propose these groups to be considered as different ESUs. According with their extent of occurrence, number of locations and inferred decline of habitat extent and quality, Central and Eastern ESUs qualify as Endangered [EN B1b(iii)] and Vulnerable [VU B1b(iii)], respectively.

This paper reports on the studies of two populations of the locally distributed damselfly Hemiphlebia mirabilis Selys in south-eastern Australia to determine the length of the maturation period, describe age-related changes in colouration, and quantify phenotypic variability in body size and wing venation. Modern odonates have a closed discoidal cell, which likely increases flight efficiency, but H. mirabilis was thought to always have an open discoidal cell in the fore wings. The study of 82 specimens documents variability in the discoidal cell character of wings as open or closed, with a minority of specimens showing all four discoidal cells closed, and others having one hind wing cell also open. Males are larger than females and body size decreases over the short flight season. Recapture histories of marked animals suggest that males emerge earlier than females and that sexual maturation takes 4–5 days. They become progressively darker, from metallic green to bronze, and their wings less flexible with age. The colour of pterostigma is sexually dimorphic. Male paraprocts and female anal valves are bright white, but in some specimens show a sky bluish tint when observed in direct daylight. Given that recent molecular studies suggest that H. mirabilis has evolved from an ancestral lineage, body colouration and wing venation may be plesiomorphic characters for this taxon.

Body colouration frequently possesses a communicative function, particularly in species with colour polymorphism and developed visual systems as odonates, and also affects the conspicuousness of animals in relation to the background. Therefore, these factors can influence colour evolution and its development. The ecology and ethology of Argia oculata (Hagen in Selys, 1865) were studied in three populations with different degrees of habitat alteration. Three different sources of colour variability were found: female polymorphism, female ontogenetic change and daily change in both sexes. All males observed presented the same blue thoracic colouration pattern, without ontogenetic changes. Some of them (6–48%, variable between populations) showed a darkening of the thorax colouration in the afternoon. The frequency of androchrome females (male-like thoracic colouration) showed a negative relationship with human habitat disturbance. These females changed their body colour from bluish to brownish at old ages. Gynochrome females started their adult life with sky-blue thorax, which turned to olive green and finally to brown with sexual maturation. One gynochrome female returned to the immature colouration in late hours of the day. Colour changes were apparently not associated to sunlight intensity or temperature. Behavioural observations suggest that colour variability in females might contribute to reduce or avoid male harassment. We contextualise our findings in the Argia literature and propose physiological and evolutionary mechanisms for their explanation.

1. The evolutionary advantages that have driven the evolution of sex are still very much debated, and a number of benefits of parthenogenesis over sexual reproduction have been proposed. In particular, parthenogenetic individuals are thought to exhibit higher probabilities of establishment following arrival in new, isolated habitats such as islands. 2. One notable example of parthenogenesis occurring in islands is the damselfly Ischnura hastata, an American species that has colonised the Azores archipelago, where the populations consist only of females. This is the only known example of parthenogenesis within the insect order Odonata. 3. Here, two island populations of I. hastata were studied, one in the Galapagos and one in Cuba, to test whether island colonisation is consistently associated with parthenogenesis in this species. Field capture–mark–recapture studies and laboratory rearing of field-collected eggs were undertaken in both areas. 4. Sex ratios in the field were found to be heavily female-biased among mature individuals; however, fertility rates of field-collected eggs were high, and the sex ratios in the laboratory did not differ from 1 : 1. Data from laboratory rearing showed that shorter larval development times and shorter adult life spans in males result in protandry, which might explain the skewed sex ratios in the field. 5. These findings are consistent with sex differences in key demographic parameters which could predispose I. hastata to parthenogenesis. However, the Azores population of I. hastata remains the only documented case of asexual reproduction in this insect group.

Hypolestes (Odonata, Zygoptera) is a damselfly genus endemic to the Greater Antilles. The genus comprises three species: H. clara from Jamaica, H. trinitatis from Cuba, and H. hatuey from Hispaniola, which are currently evaluated by the IUCN as Endangered (EN), Vulnerable (VU) and Data Deficient, respectively. Here, we re-assess the conservation status of these species based on their extent of occurrence, as estimated from ecological niche models. In addition, we analyse the coverage offered to each of the three species by the protected areas from Jamaica, Cuba, Dominican Republic and Haiti. Our results support the maintenance H. trinitatis in the category of VU, and suggest the re-classification of H. hatuey as Near Threatened. The estimated extent of occurrence for H. clara is 6422 km2, a value close to the threshold of 5000 km2 between VU and EN. Therefore, we recommend keeping H. clara as EN, until new evidence based on population size and trend could support a change from this category to VU. We found that 14 % of the extent of occurrence for H. clara and H. hatuey, and 33 % for H. trinitatis, are within protected areas. However, the ongoing extensive deforestation in Hispaniola, coupled with the lack of protection in Haiti, could cause a decrease of the extent of occurrence of H. hatuey in the future.

Alternative reproductive strategies are commonly associated with male dimorphism. In Paraphlebia zoe, a species of damselfly whose males are dimorphic in wing coloration, black-and-white-winged (BW) males defend territories, while hyaline-winged (HW) males usually play the role of satellites. We found that several BW males can sometimes share a territory, and we hypothesized that within this morph there are two alternative tactics: submissive and dominant. We conducted an experiment to test whether dominant and submissive roles are plastic or stable and fixed on each individual. To this end, we manipulated black and white spots of BW males in four treatments: (i) painting over white and black spots without changing their size, (ii) erasing the white spot using black painting, (iii) increasing the black spot and moving the white spot maintaining its size and (iv) control males. Additionally, we investigated the correlation between some phenotypic variables (wing asymmetry, survival and recapture probabilities) and male behaviour (in terms of quality of the territory). We found that the two behavioural roles (submissive and dominant) were not affected by the manipulative experiments, therefore suggesting that they are stable and fixed. Additionally, we found a positive correlation between body size and survival in both sexes, and a positive effect of territory quality and lifespan on mating success. Moreover, the largest and youngest BW males were the most symmetrical. We conclude that Paraphlebia zoe holds high behavioural diversity, with two types of strategies in BW males, dominant and submissive. The occurrence of this intra-morph behavioural diversity might depend on demographic factors such as population density and/or the relative frequency of the different morphs.

The field of sexual selection has been historically dominated by a stereotyped view of the sexual roles, with competing males and selective females, but in recent decades there has been a paradigm switch, with the emergence and dominance of the concept of sexual conflict. Put simply, there is sexual conflict when the optimum value for a trait (or a group of traits) is different for females and males. Although the recent literature mainly considers sexual conflict as a process separate from the other well-known processes in the field of postcopulatory sexual selection (sperm competition and cryptic female choice), our approach is that sexual conflict is the consequence of several pressures related to natural and sexual selection, and not a process by itself. Therefore, here we consider sexual conflict as a part of a continuum of sexual selection mechanisms. We concentrate on the effects of sexual conflict on reproductive behaviour of three groups of aquatic insects, whose habitats differ markedly, water striders, odonates and diving beetles, but also include some examples of studies addressing sexual conflict in other groups of aquatic insects. Our hypothesis is that the dimensional structure of the habitat will affect the intensity of sexual conflict over mating rate, copulation duration and postcopulatory guarding. There is abundant evidence and comprehensive reviews of the conflict over mating rates in water striders, odonates and, to a lesser degree, diving beetles. The bi-dimensionality of the water surface allows an easy monopolisation of females by males in this microhabitat, and water striders conform to this rule, so that the commonest mating system is characterised by strong conflicts and struggles before and after copulation. For animals like odonates, which are fast fliers and can use diverse terrestrial microhabitats, the opportunities for males to force females to copulate are certainly limited. In the case of diving beetles, the situation seems more favourable for the females, as they could control male approaches by hiding easily in the vegetation, or even in the case of extreme male density they could fly away and move to a different water body. The sexual conflict over mating duration is also intense in water striders, and also relevant in the other reviewed groups. In the field of postcopulatory conflicts, odonates have offered the best examples of male adaptations and female counter-adaptations, which are even more elaborated when studying the evolution of genitalia. We end by summarising our main conclusions and propose some ideas for future work. We stress that a comprehensive understanding of sexual conflicts in animals requires the study of both male and female anatomies, as well as their behaviours, avoiding assumptions or gender stereotypes, which have historically biased research to a male-view approach.

Supervivencia y longevidad de las libélulas del neotrópico (Odonata, Polythoridae) La longevidad, que entre los órdenes de insectos es muy variable, se ha estudiado principalmente en insectos de biomas templados, donde la estacionalidad determina una alta sincronización de las actividades reproductivas y limita la longevidad. La mayoría de las libélulas de las regiones tropicales vive en poblaciones con una densidad baja y casi nunca se observan en cópula. Nuestra hipótesis es que la selección favorecerá una alta tasa de supervivencia y, por lo tanto, una gran esperanza de vida, lo que permitiría que los animales estuvieran listos para los eventos ocasionales que favorecen la reproducción. Estudiamos dos libélulas neotropicales, Polythore mutata y P. derivata, en Ecuador, utilizando métodos de marcaje y recaptura. Constatamos que el sexo afectó a la tasa de recaptura, pero que solo afectó a la tasa de supervivencia diaria en una población. Hallamos indicios que sugieren la existencia de selección estabilizadora o direccional del tamaño del cuerpo. La longevidad máxima observada fue de 54–63 días. Concluimos que la tasa de supervivencia de las libélulas del género Polythore en los bosques tropicales es comparable a la de libélulas similares de las zonas templadas., Longevity among insect orders varies greatly, and has mainly been studied in insects in temperate biomes, where seasonality determines high synchronization of reproductive activities and limits lifespan. Most forest damselflies in tropical regions have low population densities and are almost never observed in copula. We hypothesized that selection will favour a high survival rate and hence high lifespan, allowing the animals to be ready for the occasional events that favour reproduction. We studied two neotropical damselflies, Polythore mutata and P. derivata, in Ecuador, using mark–recapture methods. We found that sex affected the rate of recapture, but daily survival rate was affected by sex only in one population. We found evidence that suggests stabilizing or directional selection on body size. The maximum lifespan was 54–63 days. We conclude that the survival rate of Polythore damselflies in tropical forests is comparable to that of similar damselflies in temperate zones.

International audience; Wolbachia is one of the most common endosymbionts found infecting arthropods. theory predicts symbionts like Wolbachia will be more common in species radiations, as host shift events occur with greatest frequency between closely related species. further, the presence of Wolbachia itself may engender reproductive isolation, and promote speciation of their hosts. Here we screened 178 individuals belonging to 30 species of the damselfly genera Nesobasis and Melanesobasis-species radiations endemic to the Fiji archipelago in the South Pacific-for Wolbachia, using multilocus sequence typing to characterize bacterial strains. incidence of Wolbachia was 71% in Nesobasis and 40% in Melanesobasis, and prevalence was also high, with an average of 88% in the Nesobasis species screened. We identified a total of 25 Wolbachia strains, belonging to supergroups A, B and f, with some epidemic strains present in multiple species. the occurrence of Wolbachia in both males and females, and the similar global prevalence found in both sexes rules out any strong effect of Wolbachia on the primary sex-ratio, but are compatible with the phenotype of cytoplasmic incompatibility. Nesobasis has higher species richness than most endemic island damselfly genera, and we discuss the potential for endosymbiont-mediated speciation within this group. Wolbachia is a genus of endosymbiotic α-Proteobacteria, which infects a wide range of hosts, including arthro-pods and filarial nematodes 1. Among the arthropoda, studies have estimated Wolbachia infects between 40% 2 and 52% 3 of species (including arachnids and crustaceans, but predominantly insects). A recent study on aquatic insects has estimated that 52% of these carry Wolbachia, a figure comparable to that found in terrestrial insects 4. In most cases however, a minority (

The female of Argia tupi Calvert, 1909 (BRAZIL, Mato Grosso, Chapada dos Guimarães National Park, Cachoeira do Marimbondo (15.4330° S, 55.7198° W, 370 m), 01 xi 2015) is described, illustrated and diagnosed based on comparison with sympatric species of Argia Rambur, 1842. We also augmented the description of Argia bicellulata (Calvert, 1909) female (BRAZIL, Mato Grosso, Chapada dos Guimarães National Park, Rio Paciencia (15.3438° S, 55.8322° W, 280 m), 25 x 2015).

We have examined divergence times of the Antillean damselfly genus Hypolestes, to elucidate which mechanism of allopatric speciation, vicariance or long-distance dispersal, could better explain the currently observed disjunct distributions of this genus. Samples of the three extant species of the genus, Hypolestes clara (Jamaica), H. hatuey (Hispaniola) and H. trinitatis (Cuba), were collected. Mitochondrial and nuclear DNA gene fragments were amplified to reconstruct phylogenetic relationships and estimate divergence times in this genus. Hypolestes comprises currently three species, which consist in four geographically and genetically isolated lineages located in Jamaica, Hispaniola, Eastern Cuba and Central Cuba. Results of our analyses suggest that the three species diverged between ∼5.91 and 1.69 mya, and that the separation between the lineages from Central Cuba and Eastern Cuba occurred between ∼2.0 and 0.62 mya. Disjunct distributions in the genus Hypolestes can be better explained by a long-distance dispersal mechanism, since the divergence times of the three species do not coincide with the timeline formation of the geographic barriers between Cuba, Hispaniola and Jamaica. The Cuban lineages of H. trinitatis constitute different molecular operational taxonomic units (MOTU). The elevation of these MOTU to the species category requires the analysis of additional characters.

Argia angelae sp. nov. (Holotype ♂, BRAZIL, Mato Grosso, Chapada dos Guimarães, Rio Salgadeira (15°21'25" S, 55°49'51" W, 305 m), 1 xi 2015, D. S. Vilela leg., in LESTES, Cod. ACR 8173A) from Chapada dos Guimarães, Brazil is described, illustrated and diagnosed based on comparison with other known sympatric species of the genus. This species inhabits streams throughout the National Park and a map of its known distribution is provided.

Microneura caligata (Hagen in Selys, 1886) is an endangered damselfly presently known from five localities in the central mountains of Cuba. The precise systematic position of this species within the former Neotropical Protoneuridae has been the subject of debate, with previous results from a phylogenetic analysis based on morphology suggesting that the genus Microneura should be placed within the genus Protoneura. Here, we used mitochondrial and nuclear DNA sequencing to disentangle the taxonomic status of this species. Our results show that Microneura belongs to the Protoneura clade, thus making Microneura a junior synonym of Protoneura. Finally, we provide notes on some observations of emergence and ovipositing behaviour of this species.

Rare species are expected to be more susceptible to extinction, particularly if rarity can be used to describe several characteristics for a particular species. Hemiphlebia mirabilis, an endemic damselfly known from a few sites in the South of Australia and Tasmania, has been considered at risk of imminent global extinction, given its small population size, its localised distribution, and the fact that it is a ‘living fossil’, described as the oldest extant damselfly. One population found in a protected wetland in Victoria, was studied by behavioural observations of marked animals, during Nov-Dec 2013. Results indicate that H. mirabilis is a short-lived species, with a mature lifespan of about 1 week in males and 4 days in females. Population size estimates and field observations indicate that this population is huge, likely over one million individuals per generation. Adults show little mobility and fly for short distances, being inactive most of the time, particularly at temperatures below 17 °C or over 35 °C. The low mobility and cryptic coloration, and the inaccessibility of its preferred habitat might explain why huge populations like the one studied here have remained unnoticed until recently. Nevertheless, both sexes show frequent abdominal flicking displays, and fast rotations over the perching support, both behaviours apparently unique to this species, making them highly conspicuous to human observers. It is concluded that H. mirabilis should not be regarded as critically endangered.

Dragonflies and damselflies are important study organisms in many areas of biology. Laboratory experiments with these insects have a great potential for answering evolutionary, ecological and physiological questions. Laboratory studies require insect rearing, because it can provide large sample sizes of specimens that are available throughout the year. These insects are reared under known conditions, and their use does not affect natural populations. The present paper describes a protocol to obtain at least three generations per year of Ischnura elegans in laboratory conditions, with hundreds of insects for each generation. Together with the protocol description, data from three annual laboratory populations obtained in Italy from summer 2011 to summer 2013 using this protocol are reported.

The female of Dicterias atrosanguinea Selys, 1853 is described and illustrated based on two specimens collected in Pará and Amazonas States, Brazil. We compare the female with the most closely related species, Heliocharis amazona Selys, 1853, and present SEM images of the genital ligula for both D. atrosanguinea and H. amazona males. Additionally we provide behavioral observations on D. atrosanguinea males.

Very little is known about the biology of larval odonates from the Neotropical region, and in particular there are no data on behavioral changes during ontogeny and growth ratios, though both are crucial to understanding the dynamics of Odonata communities. Here we study growth ratio, development patterns and behavior of Rhionaeschna marchali larvae. We characterized larval instars using morphometric variables and describe their general behavior. Larvae were obtained from eggs laid by two females in the laboratory. They were maintained in individual containers until their emergence or death. Larvae hatched between 26 and 30 days after laying, and total development time was 340.5 (±5.9) days, with 15 instars. Growth ratios between successive instars averaged 1.12 for head width, 1.25 for head length, 1.20 for antenna length, 1.76 for forewing–pad length, 1.74 for hind wing–pad length, 1.19 for metafemur length and 1.22 for total length. Rhionaeschna marchali larvae spent most time “resting” and “grooming”. As size increased, larvae became more active and time “resting” decreased. The behavior “upwards abdomen bend” showed a decreasing trend with size, while “body bend downwards” became more common with increasing size. The high altitude (2600 m) of the region acts as a limiting factor for growth, and therefore this species completes one generation per year, similar to many temperate species.

Confirmacion de la presencia de Ischnura senegalensis (Rambur, 1842) en las islas Canarias La presencia de una o dos especies de zigopteros del genero Ischnura en las islas Canarias ha sido objeto de debate en los ultimos anos. Los primeros registros publicados senalaban que I. senegalensis era el unico zigoptero presente en el archipielago; pero resulto no ser correcto y hasta hace poco, todos los especimenes del genero Ischnura capturados en las islas se clasificaban sin excepcion como I. saharensis. No obstante, las recientes pruebas fotograficas son compatibles con la presencia de I. senegalensis. En el presente estudio aportamos pruebas morfologicas y geneticas de la presencia de I. senegalensis en las islas Canarias, y analizamos la importancia de los especimenes de referencia para identificar correctamente especies muy parecidas.

The importance of disease-mediated invasions and the role of parasite spillover as a substantial threat to the conservation of global biodiversity are now well known. Although competition between invasive sliders Trachemys scripta elegans and indigenous European turtles has been extensively studied, the impact of this invasive species on diseases affecting native populations is poorly known. During winter 2012-2013 an unusual event was detected in a population of Emys orbicularis (Linnaeus, 1758) inhabiting a pond system in Galicia (NW Spain). Most turtles were lethargic and some had lost mobility of limbs and tail. Necropsies were performed on 11 turtles that were found dead or dying at this site. Blood flukes belonging to the species Spirorchis elegans were found inhabiting the vascular system of 3 turtles, while numerous fluke eggs were trapped in the vascular system, brain, lung, heart, liver, kidney, spleen, and/or gastrointestinal tissues of all necropsied animals. Characteristic lesions included miliary egg granulomas, which were mostly found on serosal surfaces, particularly of the small intestine, as well as endocarditis, arteritis, and thrombosis. The most probable cause of death in the 3 turtle specimens which were also examined histologically was a necrotic enteritis with secondary bacterial infection associated with a massive egg embolism. The North American origin of S. elegans, the absence of prior recorded epizootics in the outbreak area, and the habitual presence of its type host, the highly invasive red-eared slider, in this area suggest a new case of parasite spillover resulting in a severe emerging disease.

In Calopteryx damselflies, males remove rivals’ sperm stored by the female, thereby reducing sperm competition. This behaviour may create a sexual conflict, because females could lose the sperm stored in the spermatheca, used for long-term storage. Comparative evidence suggested antagonistic coevolution between sexes, which might prompt the evolution of narrow spermathecal ducts, or longer spermathecae, hindering sperm removal. Calopteryx haemorrhoidalis and C. splendens coexist and sometimes hybridize. Therefore, here I predicted that if females coevolve with conspecific males, heterospecific males should have an advantage when interspecific matings occur because females will show less resistance to them than to conspecific males. By hand-pairing females to males of both species, I found that in intraspecific and interspecific matings, sperm was almost completely removed from the bursa (97–100%), but only partially from the spermathecae, with more spermathecal removal in interspecific (63–71%) than intraspecific matings (14–33%). This suggests that heterospecific males are more efficient in sperm removal as predicted by a sexually-antagonistic coevolutionary scenario. Furthermore, in most cases, only the left spermatheca was emptied, suggesting that the evolution of more than one spermatheca might also be a female counter-adaptation to regain control over fertilization.

Lay SummaryHow genetic variation is preserved is a central issue in evolutionary biology. In many species of damselflies, females come in distinct heritable color varieties. We found that in an Iberian damselfly when subject to stressful male harassment, fecundity decreased in one kind of female but not in others. Our results, together with previous observations, suggest a scenario where differential fecundity, male preference, and fluctuations in male abundance play an important role in maintaining this variation.

The genus Franciscobasis Machado & Bedê, 2016 is endemic to the Serra da Canastra National Park in Minas Gerais state, Brazil. Two species of Franciscobasis were described simultaneously with the genus description: F. franciscoi and F. sonia, the latter described only from females. Through morphological and molecular analysis, we investigated if F. sonia may represent the young female of F. franciscoi. Resulting data did not present adequate differences between females to characterize them as different species. Therefore, we suggest that F. sonia is a junior synonym of F. franciscoi, and the female of F. franciscoi goes through a complex ontogenetic color change. Rufford Foundation | Ref. RSG 25133-2 Agencia Estatal de Investigación | Ref. PGC2018-096656-B-I00

Ornaments may show hyperallometry in certain taxa, i.e. large individuals have proportionally larger ornaments than small ones. One hypothesis suggests that higher sexual selection intensity leads to steeper hyperallometric patterns. This study tested whether an ornamental trait subject to both intra- and intersexual selection showed steeper allometric slopes than when subject solely to intrasexual selection. The study employed the sexually selected male wing pigmentation of 14 calopterygid species (damselflies) that differ in sexual selection intensity (intrasexual selection versus intra- and intersexual selection). Hyperallometry was not a uniform pattern in the study species. Furthermore, the allometric slopes did not differ between sexual selection intensities. The allometry of ornamental traits is therefore highly variable even among related species. Other selection pressures – probably species-specific and at a local scale – acting on wing pigmentation might explain the diversity of allometric patterns.

Reproductive isolation is the defining characteristic of a biological species, and a common, but often untested prediction is a positive correlation between reproductive isolation and genetic divergence. Here, we test for this correlation in odonates, an order characterized by strong sexual selection. First, we measure reproductive isolation and genetic divergence in eight damselfly genera (30 species pairs) and test for a positive correlation. Second, we estimate the genetic threshold preventing hybrid formation and empirically test this threshold using wild populations of species within the Ischnura genus. Our results indicate a positive and strong correlation between reproductive isolation and genetic distance using both mitochondrial and nuclear genes cytochrome oxidase II (COII: r=0.781 and 18S-28S: r=0.658). Hybridization thresholds range from -0.43 to 1.78% for COII and -0.052-0.71% for 18S-28S, and both F-1-hybrids and backcrosses were detected in wild populations of two pairs of Ischnura species with overlapping thresholds. Our study suggests that threshold values are suitable to identify species prone to hybridization and that positive isolation-divergence relationships are taxonomically widespread. (Less)

Recent findings suggest that postmating prezygotic isolation (i.e. gametic barriers) could be an important factor preventing hybrid formation. Competitive gametic barriers emerge when a female is inseminated by a conspecific and a heterospecific male. We examined whether sperm proportions after double matings and copulation duration impede hybrid formation. For this, we used females of Ischnura graellsii that mated with one conspecific and one heterospecific (I. elegans) male and vice versa, and calculated paternity of the second male by using RFLPs. Values of paternity (although preliminary because of a small sample size) suggest no bias in paternity towards conspecific males. However, proportion of sperm stored in the bursa and spermatheca of the female was biased towards the conspecific male when the heterospecific male was the first male, while copulation duration did not differ between conspecific and heterospecific males. Our results suggest that the relative sperm volumes may play a role as a gamet...

Twenty one polymorphic microsatellite loci were isolated from two species of dragonfly (Odonata: Anisoptera), Macromia splendens (n = 8 loci) and Oxygastra curtisii (n = 13 loci). Both species have their main distribution areas in southwestern Europe, with records in the north of Africa in the case of O. curtisii. M. splendens is listed as vulnerable by IUCN, while O. curtisii is regarded as near threatened. Genetic diversity was assessed in samples from the Iberian Peninsula representing two populations for each species. Number of alleles per locus ranged from 5 to 11 (O. curtisii) and between 4 and 16 (M. splendens), while mean expected heterozygosity varied between 0.118–0.745 (O. curtisii) and 0.130–0.849 (M. splendens). Five loci (four for O. curtisii and one for M. splendens) showed significant deviations (P