Environmental Determinates of Distribution for Dragonfly Nymphs (Odonata: Anisoptera) in Urban and Non-Urban East Texas Streams, USA

We collected environmental and habitat data for nymphs of 12 dragonfly species (Odonata: Anisoptera) from 91 stream sites throughout eastern Texas, including urban and non-urban locations. Understanding the relationship of dragonflies to habitat structure and other environmental variables is crucial for the purpose of conserving these insects and better using them as predictive tools for water quality assessments, and refining tolerance values. The objectives of this study were to determine the key environmental variables influencing the diversity and distribution of dragonflies in eastern Texas streams, and further determine if differences in those factors could be observed between urban and nonurban sites. We collected samples separately from benthic habitats and woody snag habitats. Significantly fewer sites were observed to have dragonfly species on snag habitat (mean = 1.25) compared to benthic samples (mean = 14.67) (t-test, p = 0.001). The number of dragonfly species collected among non-urban streams (mean = 9.83) was not significantly different than urban streams (mean = 6.08; t-test, p = 0.07). Detrended correspondence analysis of benthic and snag habitat data collected from non-urban and urban locations showed that most of the species are oriented most closely to benthic habitats in non-urban streams. Snag habitat was shown to be poorly ordinated for all of the species. A canonical correspondence analysis of 29 water quality and habitat variables as environmental determinants of dragonfly diversity and distribution showed that distributional relationships among species are complex and often described by multiple environmental factors.

Report of Bradinopyga konkanensis Joshi & Sawant, 2020 (Insecta: Odonata) from Kerala, India

The newly described dragonfly species, Bradinopyga konkanensis Joshi & Sawant 2020 (Insecta: Odonata), is reported from Kerala, 450 km away from its nearest record. Differences between closely similar species that co-occur in the region are tabulated for easy field identification of the species.

Comparative phylogeography uncovers evolutionary past of Holarctic dragonflies

Here, we investigate the evolutionary history of five northern dragonfly species to evaluate what role the last glaciation period may have played in their current distributions. We look at the population structure and estimate divergence times for populations of the following species: Aeshna juncea (Linnaeus), Aeshna subarctica Walker, Sympetrum danae (Sulzer), Libellula quadrimaculata Linnaeus and Somatochlora sahlbergi Trybom across their Holarctic range. Our results suggest a common phylogeographic pattern across all species except for S. sahlbergi. First, we find that North American and European populations are genetically distinct and have perhaps been separated for more than 400,000 years. Second, our data suggests that, based on genetics, populations from the Greater Beringian region (Beringia, Japan and China) have haplotypes that cluster with North America or Europe depending on the species rather than having a shared geographic affinity. This is perhaps a result of fluctuating sea levels and ice sheet coverage during the Quaternary period that influenced dispersal routes and refugia. Indeed, glacial Beringia may have been as much a transit zone as a refugia for dragonflies. Somatochlora sahlbergi shows no genetic variation across its range and therefore does not share the geographic patterns found in the other circumboreal dragonflies studied here. Lastly, we discuss the taxonomic status of Sympetrum danae, which our results indicate is a species complex comprising two species, one found in Eurasia through Beringia, and the other in North America east and south of Beringia. Through this study we present a shared history among different species from different families of dragonflies, which are influenced by the climatic fluctuations of the past.

Application of eDNA method in the detection of Cordulegaster (Insecta: Odonata) species

The aim of this pilot study was to investigate the potential of eDNA techniques to detect the presence of the two dragonfly species Cordulegaster heros and Cordulegaster bidentata. Both species are classified as “near threatened” according to the IUCN Red List and are strictly protected in several countries. Monitoring these species with traditional sampling methods is often difficult, time-consuming and invasive. In this pilot study, we first collected tissue samples from C. heros and C. bidentata to sequence the traditional DNA-barcode gene fragment COI. We then collected further dragonfly COI sequences from BOLD to design species-specific primers. This, however, was impossible given the enormous variability of COI. Therefore, we refrained from species-specific eDNA assays and followed eDNA metabarcoding protocol using universal (BF2/BF2) and a newly designed dragonfly specific primer. For the evaluation of the method, we took water samples from places where Cordulegaster specimens are known to occur. After the extraction, we used two sequential PCR steps for obtaining the desired amplicon (two-step PCR) using universal primers in the first step, and group (dragonfly) specific primers or universal primers. Amplicons were sequenced on an Illumina MiSeq platform and then analysed the data with the JAMP pipeline. With the newly designed primers and we could effectively detect the targeted dragonfly species from tissue samples, and also from filtered environmental samples. The detection of the species with the traditional method is time consuming and involves the destruction of the specimens. In comparison, with the eDNA method we could easily detect these near threatherned odonates and other dragonfly species in a non-invasive way.

The influence of relief morphometric characteristics upon the occurrence of the species Cordulegaster bidentata in the particular conditions of the Western Carpathians

The study concerns a monitoring survey of Cordulegaster bidentata Selys, 1843 (Odonata, Cordulegastridae), which is considered near threatened in the European Red List of Dragonflies, in order to show its habitat preferences and clarify the influence of slope and orientation of slopes on the occurrence of the species. Investigations of water habitats were carried out during the period from 2019 to 2020 in the Kysuce Region in northwest Slovakia. The protocol consists of looking for larvae and characterizing larval micro-habitat of C. bidentata so as to show their habitat preferences and clarify the influence of slope and orientation of slopes on the occurrence of the species. We sampled 32 watercourses (epicrenal, hypocrenal, rheocren, heleocren, epirhithral, metarhithral) at altitudes 420–950 m above sea level. A total of 79 larvae and 10 imagines (7♂ 3♀) of C. bidentata were found at 12 streams. In the present study, C. bidentata clearly preferred first-order stream sections, the slopes were steep and the proportion of small sediment grain sizes was high. The results show that the number of C. bidentata larvae grew with the increasing percentage of forests around streams. We also confirmed the trend for the number of C. bidentata larvae to increase with increasing values of slope and altitude of watercourses. Most of the individuals were recorded at the south and southwest oriented streams; we did not record larvae on the north and northwest oriented slopes. We assume that more suitable conditions for development of population exist in the streams on the south and southwest oriented slopes. The preference for watercourses oriented south and southwest ensures optimal conditions for the development of the population of this dragonfly species. The finding of larvae at the stages of instars shows the permanent occurrence of the species in the Kysuce Region.

Macromia weerakooni sp. nov. (Odonata: Anisoptera: Macromiidae), a new dragonfly species from Sri Lanka

The genus Macromia is represented in Sri Lanka by two endemic species. In this paper a third presumed endemic species is described based on a single male specimen collected at Kirikitta, Weliweriya, Western Province in the low country wet zone of the country. Macromia weerakooni sp. nov. differs from its congeners in Sri Lanka by having turquoise blue eyes, an entirely black labrum, a short yellow ante-humeral stripe, an interrupted yellow stripe on the anterior margin of metepisternum anddifferences in the secondary genitalia and anal appendages. As this is the only record of the species knowledge of its natural history and distribution is limited. This discovery highlights the need for further systematic surveys of Odonata in Sri Lanka using sampling methods suitable for the detection of elusive species.

KEANEKARAGAMAN JENIS CAPUNG (ODONATA) PADA AREAL PERSAWAHAN DI KECAMATAN TABIR DAN DI KECAMATAN PANGKALAN JAMBU KABUPATEN MERANGIN

Penelitian ini bertujuan untuk mengetahui jenis-jenis dan keanekaragaman jenis-jenis capung (odonata) di kawasan sawah Kec. Pangkalan jambu dan Kec. Tabir Kabupaten Merangin. Pengambilan sampel capung dilakukan di Kecamatan Pangkalan Jambu (Desa Bungo Tanjung dan Tanjung Mudo) dan Kecamatan Tabir (Desa Seling dan Desa Kampung Baru) Kabupaten Merangin. Identifikasi capung dilakukan di Laboratorium Universitas Muara Bungo. Penelitian ini dimulai dari tanggal 03 Februari 2019 sampai dengan tanggal 30 April 2019.Penelitian ini berbentuk survei dan metode pengambilan sampel yang digunakan adalah Purposive Random Sampling. Pada tiap kecamatan dipilih dua desa sebagai tempat pengamatan. Pada tiap petak pertanaman ditentukan petak sampel yang berukuran 5 x 5 m secara sistematis pada garis diagonal. Pengambilan sampel Capung di lapangan dilakukan sebanyak 6 kali dengan interval pengambilan sampel dua minggu sekali yang dilakukan dengan dua metode yaitu koleksi secara langsung yaitu menangkap dengan tangan setiap Capung yang ditemukan pada petak sampel dan Metode jaring ayun. Adapun Variabel yang diamati adalah Identifikasi capung, Indeks Keanekaragaman, Indeks Kemerataan Spesies dan Kekayaan Spesies.Hasil penelitian menunjukan bahwa jenis-jenis capung (odonata) pada aeral persawahan di Kecamatan Pangkalan Jambu adalah 12 spesies dan 10 spesies di Kecamatan Tabir dengan rincian 8 spesies yang sama yaitu Crocodemis servilia, Orthetrum chrysis, Orthetrum testaceum, Orthetrum pruinosum, Orthetrum sabina, Diplacodes travilis, Agriocenemis femina, Agriocenemis pygmea, dan 6 spesies yang berbeda Pseudagrio pruinosum, Coriagrio colamineum, Orthetrum glaucum, Potamarcha congener, Libellago lineata dan Copera marginipes. Keanekaragaman jenis-jenis capung (odonata) yang ada di kawasan sawah Kecamatan Pangkalan jambu dan kecamatan Tabir Kabupaten Merangin berada pada tingkat sedang dengan indeks keanekaragaman sebesar 2,03 – 2,15, tingkat kemerataan yang stabil dengan indeks kemerataan 0,86-0,88 serta areal persawahan di kecamatan Pangkalan Jambu memiliki kekayan spesies yang lebih tinggi dibandingkan kawasan sawah kec. Tabir. Kata Kunci :Keanekaragaman, Spesies Capung, Areal Persawahan This study aimed to determine types and diversity of dragonflies species (odonata) in Pangkalan Jambu District and Tabir District Merangin Regency. The sampling of dragonflies was carried out in Pangkalan Jambu District (Bungo Tanjung Village and Tanjung Mudo village) and Tabir District (Sling Village and kampung baruh Village) Merangin Regency. Identification of dragonflies was carried out at the Muara Bungo University Laboratory. This study began from February, 3th to April, 30th 2019.This research takes the form of a survey and kind of the sampling method is Purposive Random Sampling. In each district two villages were chosen as observation sites. In each planting plot, a sample plot of 5 x 5 m was determined systematically on a diagonal line. Dragonfly sampling in the field was carried out as much as 6 times with biweekly sampling intervals which were carried out by two methods, namely direct collection, with catching by hand every dragonfly found in the sample plot and swinging method. The variables observed were dragonfly identification, diversity index, species evenness and species richness index.The results showed that the types of dragonflies (odonata) in rice fields in Pangkalan Jambu district were 12 species and 10 species in Tabir district with details of the same 8 species namely Crocodemis servilia, Orthetrum chrysis, Orthetrum testaceum, Orthetrum pruinosum, Orthetrum sabina, Diplacodes travilis, Agriocenemis femina, Agriocenemis pygmea, and 6 different species of Pseudagrio pruinosum, Coriagrio colamineum, Orthetrum glaucum, Potamarcha congener, Libellago lineata and Copera marginipes. The diversity of dragonfly species (odonata) in the paddy field of Pangkalan jambu district and Tabir district of Merangin Regency is at a moderate level with a diversity index of 2.03 - 2.15, a stable level of evenness with an evenness index of 0.86-0, 88 and rice fields in the Pangkalan Jambu district have higher species richness compared to the rice field area. Keywords: Diversity, Dragonflies, Rice Fields

Integrating high-speed videos in capture-mark-recapture studies of insects

Capture-mark-recapture (CMR) studies have been used extensively in ecology and evolution. While it is feasible to apply CMR in some animals, it is considerably more challenging in small fast-moving species such as insects. In these groups, low recapture rates can bias estimates of demographic parameters, thereby, handicapping effective management of wild populations. Here we use high-speed videos (HSV) of the adults of two large dragonfly species that rarely land and, thus, are particularly challenging for CMR studies. We specifically test whether HSV, compared to conventional eye observations, increases the “resighting” rates and improves the certainty of the estimates of survival rate, and the effects of demographic covariates on survival rates. We show that the use of HSV increases the number of resights substantially. HSV improved our estimates of resighting and survival probability which were either under- or overestimated with the conventional observations. HSV increased the accuracy of the estimates of effect sizes of important covariates (age and body size). Integrating HSV in CMR of highly mobile animals is valuable because it is easy, non-invasive, and has the potential to improve demographic estimates. Hence, it opens the door for a wide range of research possibilities on species that are traditionally difficult to monitor, including within insects, birds, and mammals.