Diversity of the Anisoptera & Zygoptera (Odonata: Insecta) of Swat, Pakistan

Odonates are important biological control agents for the control of insect pests and insect disease vectors of medical and veterinary importance. The present study was conducted to evaluate the odonate fauna of Swat, Pakistan from March to October 2019. A total of 200 specimens of odonates were collected from diverse habitats. The collected specimens of the order Odonata belonged to 5 families, three families of suborder Anisoptera namely Libellulidae, Gomphidae and Aeshnidae while two families of suborder Zygoptera (Chlorocyphidae and Coenagrionidae). The specimens were categorized into 12 genera and 22 species. Libellulidae was the dominant family (n = 138) accounting for 69% of the odonate fauna. Orthetrum was the dominant genus (n = 73) of suborder Anisoptera accounting for 36.5% of the odonate fauna. The least dominant genera were Anax, Paragomphus and Rhyothemis (n = 5 each) accounting each for 2.5% of the odonate fauna. In Zygoptera, the dominant genus was Ceriagrion (12.5%) and the least dominant genus was Ischnura (6%). Pantala flavescens (Fabricius, 1798) was the most abundant odonate species in the study area recorded from all surveyed habitats. Shannon Diversity Index (H) was 2.988 and Simpson Diversity Index (D) was 0.95 for the collected odonate fauna. The highest abundance of Odonata was recorded in August, September and May while no odonate species were recorded in January, February, November and December. Lotic water bodies were the most suitable habitats with abundant odonate fauna. Anax immaculifrons (Rambur, 1842) was the largest sized odonate species having a wingspan of 53.2±1.63 mm and body length of 56.3 ± 0.4 mm. The present study shows the status of odonate fauna of Swat, Pakistan in diverse habitats and seasonsonal variation throughout the year. Further work is recommended to bridge the gaps in the existing literature.

Odonata Diversity in Thadiyankudisai, Palni Hills of Western Ghats, Tamil Nadu

A total of 419 individuals under 5 families, 8 genera and 10 species of Odonata were recorded in the present study. Among them family Libellulidae had 6 species followed by Chlorocyphidae (2 species), and Coenagrionidae and Euphaeidae had1 species. The dominance order of Odonata was Pantala flavescens (44.40%) > Diplacodes trivialis (22.70%) > Orthetrum chrysis (7.40%) while rest of the fauna ranged from (1.40 to 6.90%). Pantala flavescens was maximum during NEM (50.0%) followed by summer and winter (43.8% each) and minimum during SWM (38.5%). Margalef Index of Species Richness was highest (2.00) during winter. Simpson Index of Diversity was highest (0.75) during SWM while Shannon-Wiener Index of Dominance was highest (1.75) during summer. The species were evenly distributed during summer with Pielou’s Evenness Index value of 0.76. The community change was 80.00 per cent change during January, 2018 and had a steep fall in February and April, 2018 and reached a peak of 66.67 per cent during March and November, 2018.

Distributions of total mercury and methylmercury in dragonflies from a large abandoned mercury mining region in China

Dragonflies (Order Odonata) are often considered to be biosentinels of environmental contamination. Dragonflies (n = 439) belonging to 15 species of eight genera were collected from an abandoned mercury (Hg) mining region in China to investigate the bioaccumulation of total Hg (THg) and methylmercury (MeHg). The THg and MeHg concentrations in dragonflies varied widely within ranges of 0.06–19 mg/kg and 0.02–5.7 mg/kg, respectively. THg and MeHg were positively correlated with bodyweight (THg: r2 = 0.10, P = 0.000; MeHg: r2 = 0.09, P = 0.000). Significant variations were observed among species, with the highest MeHg value (in Orthetrum triangulare) being 5-fold higher than the lowest (in Pantala flavescens). These variations were consistent with those of nitrogen isotope (δ15N) values. A health risk assessment found hazard quotients for specialist dragonfly-consuming birds of up to 7.2, which is 2.4 times greater than the permissible limit of 3, suggesting a potential health risk of exposure.

Kelimpahan capung di sepanjang Danau Kenanga hingga Kebun Fakultas Ilmu Keperawatan Universitas Indonesia

Kebun dengan ketersedian air yang cukup dapat dijadikan sebagai habitat bagi Odonata untuk bertahan hidup dan berkembang biak. Penelitian bertujuan mengetahi kelimpahan capung sepanjang Danau Kenanga hingga kebun Fakultas Ilmu Keperawatan, Universitas Indonesia, Depok, Jawa Barat. Jenis penelitian adalah penelitian deskriptif-eksploratif. Penelitian dilakukan dengan metode TTLTK (Tangkap Tandai Lepas Tangkap Kembali). Metode dilaksanakan dengan metode jalur transek, penyusuran jalur yang terdiri dari tiga jalur yaitu jalur kiri, jalur kanan, dan jalur tengah atau jalur air. Teknik analisis data menggunakan rumus indeks kelimpahan spesies dan rumus indeks keanekaragaman Shannon-Wiener. Hasil penelitian menunjukkan indeks kelimpahan dan nilai indeks keanekaragaman capung termasuk kedalam tingkatan rendah. Ditemukan capung sebanyak 52 individu yang terdiri dari 7 spesies. Pantala flavescens adalah spesies yang paling banyak ditemukan dengan jumlah individu sebanyak 41. Didapatkan pula nilai indeks keanekaragaman yakni 0.81649, termasuk kedalam kategori keanekaragaman tingkat rendah karena H’ < 1 diduga karena kondisi lingkungan mengganggu perkembang biakkan capung. Dapat disimpulkan bahwa kelimpahan capung berbanding lurus dengan keanekaragaman capung.

Odonata from Batanta (Indonesia, West Papua) with description of one new species

Fifty-eight taxa of Odonata are herewith reported from Batanta Island (including Arefi and Birie Islands). One new species is described: Argiolestes varga sp. nov. The following ten species are new to the Raja Ampat Islands: Papuagrion magnanimum (Selys, 1876), Gynacantha rosenbergi Kaup, 1867, Palaeosynthemis cf. cervula (Lieftinck, 1938), Diplacina smaragdina Selys, 1878, Nannophlebia amphicyllis Lieftinck, 1933, Pantala flavescens (Fabricius, 1798), Rhodothemis nigripes Lohmann, 1984, Rhyothemis regia (Brauer, 1867), Tramea transmarina propinqua Lieftinck, 1942, Zyxomma multinervorum Carpenter, 1897, and fifteen are new to Batanta: Selysioneura cornelia Lieftinck, 1953, P. magnanimum, Agyrtacantha dirupta (Karsch, 1889), Anax maclachlani Förster, 1898, G. rosenbergi, P. cf. cervula, D. smaragdina, N. amphicyllis, Nesoxenia mysis (Selys, 1878), P. flavescens, R. nigripes, R. regia, Tetrathemis irregularis Brauer, 1868, T. transmarina propinqua, Z. multinervorum. Metagrion postnodale (Selys, 1878) and Selysioneura cf. cervicornu Förster, 1900 are deleted from the faunal lists of Odonata of Raja Ampat and Batanta Islands. The total number of species recorded for Batanta Island is 62.

Seasonal Migrations of Pantala flavescens (Odonata: Libellulidae) in Middle Asia and Understanding of the Migration Model in the Afro-Asian Region Using Stable Isotopes of Hydrogen

In Middle Asia, the dragonfly Pantala flavescens makes regular seasonal migrations. In spring, sexually mature dragonflies (immigrants) arrive in this region for reproduction. Dragonflies of the aboriginal generation (residents) develop in about two months, and migrate south in autumn. Residents of Middle Asia have significantly lower δ2H values (−123.5 (SD 17.2)‰, n = 53) than immigrants (−64.4 (9.7)‰, n = 12), as well as aboriginal dragonfly species from Ethiopia (−47.9 (10.8)‰, n = 4) and the Sahel zone (−50.1 (15.5)‰, n = 11). Phenological data on P. flavescens in the Afro-Asian region and a comparison with published isotopic data on migratory insects from this region suggest that (i) the probable area of origin of P. flavescens immigrants is located in tropical parts of East Africa and/or the Arabian Peninsula and (ii) the autumn migration of Middle Asian residents to the south may also pass through the Indian Ocean. We assume that in the Afro-Asian region, there is an extensive migration circle of P. flavescens covering East Africa, Central Asia and the Indian subcontinent with a total length of more than 14,000 km.

Dragonflies and damselflies (Odonata) from Flores Island, Lesser Sunda Archipelago: New occurrences in extreme environments and an island-level checklist of this group

Although the Odonata are common inhabitants of various extreme environments such as geothermal springs, brackish wetlands, mangroves, and volcanic lakes, the assemblages of this group associated with extreme habitats in Australasia are rather poorly known. Here, we combine museum collection data and published reports on Odonata from extreme habitats on Flores Island, Lesser Sunda Archipelago. The highly acidic Sano Nggoang Crater Lake (mean pH = 3.17) on Flores houses seven species as follows: Agriocnemis pygmaea, Xiphiagrion cyanomelas (Coenagrionidae), Neurothemis ramburii, Orthetrum pruinosum pruinosum, O. sabina, O. testaceum soembanum (Libellulidae), and Anax gibbosulus (Aeshnidae). A coastal marsh site with slightly brackish water on Flores harbors at least five dragonfly species as follows: Diplacodes trivialis, Neurothemis intermedia excelsa, N. terminata, Pantala flavescens, and Rhyothemis phyllis ixias (Libellulidae). The migratory dragonfly Pantala flavescens was a single species recorded on the waterless Kanawa Island near the western edge of Flores. Our findings suggest that extreme habitats in eastern Indonesia primarily colonized by widespread generalist Odonata species. Finally, an updated checklist of Odonata species recorded from Flores Island was compiled. Our survey of museum specimens recovered two species not found on existing species lists for Flores: Neurothemis intermedia excelsa and Pantala flavescens.

Behavioral responses of tadpoles of Duttaphrynus melanostictus (Anura: Bufonidae) to cues of starved and fed dragonfly larvae

Behavioral responses of tadpoles of Duttaphrynus melanostictus (Anura: Bufonidae) to cues of starved and fed dragonfly larvae. Tadpoles of Duttaphrynus melanostictus use chemoreception to detect kairomonal cues and excretory metabolites from predatory anuran tadpoles (Hoplobatrachus tigerinus) that consume them. We describe here the behavioral responses of tadpoles of D. melanostictus to predatory dragonfly larvae (Pantala flavescens). The predator’s kairomones (water conditioned by the starved predator) or its diet-derived metabolites released in excreta of predator after consumption of conspecific prey tadpoles were used to simulate predation risk. The tadpoles of D. melanostictus had no behavioral response to predator kairomones. However, the larvae reduced swimming movements and overall time spent in swimming, and had a higher burst speed/swimming velocity in response to water borne cues released from the excreta of predators fed conspecific prey. Thus, just the presence of dragonfly larvae does not elicit defense behaviors in tadpoles of D. melanostictus, but when predation risk is recognized as real (i.e., when tadpoles are exposed to excretory metabolites of predators fed conspecific tadpoles), defense behaviors are activated.