Variations in the Odonata Assemblages: How Do the Dry Season and Water Bodies Influence Them?

Diverse abiotic and biotic factors drive the ecological variation of communities across spatial and temporal dimensions. Within the Amazonian landscape, various freshwater environments exhibit distinct physicochemical characteristics. Thus, our study delved into the fluctuations of Odonata assemblages amidst distinct water bodies within Amazonia, encompassing two distinct climatic seasons. Comparative analysis was conducted on Odonata species diversity and assemblage composition across a blackwater pond, a lake, and a stream, spanning the initiation and culmination of the dry season in the southwestern Amazon region in Peru. Our methodology involved capturing adult Odonata using entomological nets on three separate occasions between 11:00 and 14:00 h for each water body in May (beginning of the dry season) and October (end of the dry season) of 2018. We also evaluated the influence of temperature, precipitation, and percent cloud cover on the abundance and richness of adult Odonata. Species richness and composition differed among the three water bodies in both periods of the dry season. No effect of the dry season periods on species richness and abundance was observed. However, except in the oxbow lake, the more abundant species were substituted to the end of the dry season. Our study highlights the influence of water body types on Odonata species diversity and composition. The effects of the sampling period during the dry season may not be immediately apparent in conventional diversity metrics, such as species richness and abundance. Instead, its effects manifest predominantly in the relative abundance of the species that compose these assemblages.

Diversity of the Anisoptera & Zygoptera (Odonata: Insecta) of Swat, Pakistan / Diversidade de Anisoptera e Zygoptera (Odonata: Insecta) de Swat, Paquistão

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.

Odonatos são importantes agentes de controle biológico para o controle de insetos-praga e vetores de doenças de insetos de importância médica e veterinária. O presente estudo foi conduzido para avaliar a fauna de odonatos de Swat, Paquistão, de março a outubro de 2019. Um total de 200 espécimes de odonatos foi coletado em diversos habitats. Os espécimes coletados da ordem Odonata pertenciam a cinco famílias, três famílias da subordem Anisoptera, a saber, Libellulidae, Gomphidae e Aeshnidae, enquanto duas famílias eram da subordem Zygoptera (Chlorocyphidae e Coenagrionidae). Os espécimes foram classificados em 12 gêneros e 22 espécies. Libellulidae foi a família dominante (n = 138), respondendo por 69% da fauna de odonatos. Orthetrum foi o gênero dominante (n = 73) da subordem Anisoptera, responsável por 36,5% da fauna de odonatos. Os gêneros menos dominantes foram Anax, Paragomphus e Rhyothemis (n = 5 cada), representando cada um 2,5% da fauna de odonatos. Em Zygoptera, o gênero dominante foi Ceriagrion (12,5%), e o gênero menos dominante foi Ischnura (6%). Pantala flavescens (Fabricius, 1798) foi a espécie de odonato mais abundante na área de estudo, registrada em todos os habitats pesquisados. O Índice de Diversidade de Shannon (H) foi de 2,988, e o Índice de Diversidade de Simpson (D) foi de 0,95 para a fauna de odonatos coletados. A maior abundância de Odonata foi registrada em agosto, setembro e maio, enquanto nenhuma espécie de Odonata foi registrada em janeiro, fevereiro, novembro e dezembro. Corpos d’água lóticos foram os habitats mais adequados, com abundante fauna de odonatos. Anax imaculifrons (Rambur, 1842) foi a espécie de odonato de maior tamanho, com envergadura de 53,2 ± 1,63 mm e comprimento do corpo de 56,3 ± 0,4 mm. O presente estudo mostrou o status da fauna de odonatos de Swat, Paquistão, em diversos habitats e variação sazonal ao longo do ano. Recomenda-se trabalho adicional para preencher as lacunas na literatura existente.

Insect thermal limits in warm and perturbed habitats: Dragonflies and damselflies as study cases.

Disturbance (e.g. loss of plant cover) increases ambient temperature which can be lethal for ectotherm insects especially in hot places. We compared the thorax temperatures of 26 odonate species as a function of body size, habitat quality ("conserved" and cooler vs "perturbed" and warmer) and suborder (Anisoptera vs Zygoptera), as well as critical thermal maximum (CTmax) and as a function of habitat quality in Argia pulla (Zygoptera) and Orthemis ferruginea (Anisoptera). We expected thorax temperatures to differ between suborders based on their differences in body size and habitat quality status, and that populations in perturbed sites would have higher critical thermal maxima compared to those in conserved sites. This study was done in a tropical region with high ambient temperatures. Anisopterans had a higher body temperature than zygopterans, with no difference between habitats. Thoracic and air temperature were positively related, yet body temperatures were higher than the ambient temperature. A. pulla had higher CTmax in the perturbed sites, while O. ferruginea showed the opposite trend. Microenvironmental changes increase the ambient temperature, perhaps filtering insect species. The apparent resilience of odonates to disturbance should be examined more closely (using more species), especially in small species like the zygopterans which appear to be more strongly affected by ambient temperature.

Perilestes jueni (Zygoptera: Perilestidae), new species from Amazonas State, Northern Brazil.

Perilestes jueni sp. nov. (Brazil, Amazonas State, São Gabriel da Cachoeira, Ponto 8 (0.165, -67.007, 92 m asl), 2.xii.2021, C.C. Mendoza-Penagos M. Silva-Gonçalves & S. Da Silva Ribeiro leg.) is described based on one male collected in a remote area of the Brazilian Amazon Forest. The new species is separated from congeners based on cercus morphology.

Description of the larva of Planiplax sanguiniventris (Calvert, 1907) (Odonata: Libellulidae).

The last instar larva of Planiplax sanguiniventris (Calvert, 1907) is described and illustrated in detail based on one specimen collected in the municipality of Tenosique, Tabasco, Mexico. It is compared with the larvae of P. phoenicura Ris, 1912 and a congeneric unidentified species from Colombia. The main structural features are the number of setae on palp and prementum, the size of dorsal protuberance on S3, and the length of posterolateral spines on S89 and caudal appendages.

Description of the larva of Brachygonia oculata (Brauer, 1878) (Odonata: Libellulidae) with notes on rearing technique.

The larva of the genus Brachygonia Kirby, 1889 is described and illustrated for the first time based on the larvae of Brachygonia oculata (Brauer, 1878) discovered and successfully reared in Singapore. Compared to known larvae from genera in the rather heterogeneous subfamily Brachydiplacinae, B. oculata is most similar to species from the genus Brachydiplax Brauer, 1868 after comparison is made with the larva of Brachydiplax farinosa Krüger, 1902.

Heteragrion lencionii (Odonata: Heteragrionidae) sp. nov. from Serra de Itabaiana National Park, Northeastern Brazil.

The Neotropical genus Heteragrion Selys, 1862 is one of the most speciose among Zygoptera. Notwithstanding, most of its species are poorly known, especially those from undersampled areas such as Northeastern Brazil. Here, we describe Heteragrion lencionii sp. nov., from protected areas of Sergipe state (Holotype ♂, Brazil, Sergipe, Areia Branca, Serra de Itabaiana National Park, -10.7484, -37.3390, 179 m, 7.xii.2020, A.B. Farias A.E. dos Santos leg., in UFS). This is only the second Heteragrion species discovered as new for the Northeastern region of Brazil, separated from other congeners by cercus morphology and thoracic coloration pattern.

A new genus and species of Euphaeidae (Odonata, Zygoptera) from the early Eocene Okanagan Highlands locality at Republic, Washington, U.S.A.

We describe Republica weatbrooki, a new genus and species of damselfly (Odonata, Zygoptera, Euphaeidae, Eodichromatinae) from the early Eocene (Ypresian) fossil locality at Republic, Washington, U.S.A. Its single specimen is the sole damselfly known from the Okanagan Highlands series of localities in far-western North America.

Description of Chlorogomphus danhkyi sp. nov. from Vu Quang National Park, central Vietnam with notes on other congeners from the Park (Odonata: Chlorogomphidae).

Chlorogomphus danhkyi sp. nov. (Holotype ♂: Khe Ro, Vu Quang National Park, Ha Tinh Province, 15.0444 N, 107.9270 E, altitude 1480 m) based on both sexes is described. The new species differs from Chlorogomphus piaoacensis Karube, 2013 mainly by the shape of male cerci. Other species of Chlorogomphus Selys, 1854 from Vu Quang National Park are also recorded.

Description of the larva of Micrathyria paulsoni González-Soriano, 2020 (Odonata: Libellulidae).

The last instar larva of Micrathyria paulsoni González-Soriano, 2020 is described and illustrated in detail based on specimens collected in Veracruz State, Mexico. It is compared with the larvae of M. didyma (Selys in Sagra, 1857) and M. hypodidyma Calvert, 1906, all of them belonging into the "Micrathyria didyma" group. The main structural features of M. paulsoni larva are 910 long premental setae plus 45 small setae, palpal setae 10, legs banded, a large, submedian, dark spot on each side of a pale middorsal line on S69, S89 with a posterolateral spine, larger in S9.

Synopsis of Lestes from Brazil with description of Lestes demarcoi sp. nov. (Zygoptera: Lestidae).

The Brazilian fauna of Lestidae contains two genera (Archilestes Selys, 1862 and Lestes Leach in Brewster, 1815) with 14 species, many of which are poorly defined and/or known only by primary literature. To improve the knowledge of the Brazilian species of the genus Lestes we examined 97 specimens pertaining to 11 of the 13 described species. Additionally, a new species is described here in honor to Prof. Dr. Paulo De Marco Júnior: Lestes demarcoi (Holotype and Allotype: Brazil: Amazonas, Manaus, Reserva Adolpho Ducke, Acará trail, 02º55'46" S 59º58'22" W, 62 m, 13.iv.2009, collected in tandem, U.G. Neiss leg. and deposited in FAAL). Diagnostic illustrations of all species are provided. Color photographs of live individuals of Lestes dichrostigma Calvert, 1909, Lestes forficula Rambur, 1842 and Lestes paulistus Calvert, 1909 are also presented.

First description of the female of Coeliccia furcata Hämäläinen, 1986, with descriptive notes on males from Yunnan, China (Odonata: Zygoptera: Platycnemididae).

Coeliccia furcata Hämäläinen, 1986, an atypical species of Coeliccia Kirby, 1890 with bifurcated male cerci, had been known solely from the holotype male collected in Myanmar in 1938. In recent years the species has been rediscovered in Yunnan, China. The first description of the female is given, along with descriptive notes on the male and illustrations of both sexes, including fresh images of the holotype. Another of the unusual features of C. furcata is the extremely simple form of its penile organ, this is discussed and compared with other species from mainland Asia and Japan currently placed in Coeliccia and with a simple penile organ.

Leptagrion itabaiana sp. nov. (Odonata: Coenagrionidae) from Serra de Itabaiana National Park, Sergipe state, Northeastern Brazil.

Leptagrion itabaiana sp. nov. (Brazil, Sergipe, Areia Branca, Serra de Itabaiana National Park, (10.7517 S, 37.3415 W, 179 m asl), 3.ii.2021, J.C. Santos leg.) is described, diagnosed, illustrated and compared with morphologically close congeners based on male specimens. The new species can be separated from other Leptagrion species mainly by cercus morphology.

Zootaxa 20th Anniversary Celebration: Odonata section.

During the two decades (20012020) of the journal's existence, 346 papers on Odonata were published in Zootaxa. These papers contributed 317 new extant taxa, 26 new fossil taxa, and 106 new larval descriptions. By the end of the period, papers in Zootaxa were contributing slightly more than half of all descriptions of new extant taxa. Research was published from all over the world but predominantly from the American and Asian tropics, and authors from 42 countries contributed papers.

Heteragrion/ gorbi/ sp. nov. (Odonata: Heteragrionidae) from southeastern Brazil.

Heteragrion gorbi sp. nov. (Zygoptera: Heteragrionidae) is described and diagnosed based on six ♂♂ and one ♀. The specimens were collected in a stream in a Neotropical savannah fragment in São Carlos, São Paulo, Brazil. We present pictures of the holotype and the female. This is a species with blue coloration pattern, rare among its congeners.

A molecularphylogeny offorktail damselflies(genus Ischnura)revealsa dynamic macroevolutionary history of female colour polymorphisms.

Colour polymorphisms are popular study systems among biologists interested in evolutionary dynamics, genomics, sexual selection and sexual conflict. In many damselfly groups, such as in the globally distributed genus Ischnura (forktails), sex-limited female colour polymorphisms occur in multiple species. Female-polymorphic species contain two or three female morphs, one of which phenotypically matches the male (androchrome or male mimic) and the other(s) which are phenotypically distinct from the male (heterochrome). These female colour polymorphisms are thought to be maintained by frequency-dependent sexual conflict, but their macroevolutionary histories are unknown, due to the lack of a robust molecular phylogeny. Here, we present the first time-calibrated phylogeny of Ischnura, using a multispecies coalescent approach (StarBEAST2) and incorporating both molecular and fossil data for 41 extant species (55% of the genus). We estimate the age of Ischnura to be between 13.8 and 23.4 millions of years, i.e. Miocene. We infer the ancestral state of this genus as female monomorphism with heterochrome females, with multiple gains and losses of female polymorphisms, evidence of trans-species female polymorphisms and a significant positive relationship between female polymorphism incidence and current geographic range size. Our study provides a robust phylogenetic framework for future research on the dynamic macroevolutionary history of this clade with its extraordinary diversity of sex-limited female polymorphisms.

Phylogeny and classification of Odonata using targeted genomics.

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.

Italian odonates in the Pandora's box: A comprehensive DNA barcoding inventory shows taxonomic warnings at the Holarctic scale.

The Odonata are considered among the most endangered freshwater faunal taxa. Their DNA-based monitoring relies on validated reference data sets that are often lacking or do not cover important biogeographical centres of diversification. This study presents the results of a DNA barcoding campaign on Odonata, based on the standard 658-bp 5' end region of the mitochondrial COI gene, involving the collection of 812 specimens (409 of which barcoded) from peninsular Italy and its main islands (328 localities), belonging to all the 88 species (31 Zygoptera and 57 Anisoptera) known from the country. Additional BOLD and GenBank data from Holarctic samples expanded the data set to 1,294 DNA barcodes. A multi-approach species delimitation analysis involving two distance (OT and ABGD) and four tree-based (PTP, MPTP, GMYC and bGMYC) methods was used to explore these data. Of the 88 investigated morphospecies, 75 (85%) unequivocally corresponded to distinct molecular operational units, whereas the remaining ones were classified as 'warnings' (i.e. showing a mismatch between morphospecies assignment and DNA-based species delimitation). These results are in contrast with other DNA barcoding studies on Odonata showing up to 95% of identification success. The species causing warnings were grouped into three categories depending on if they showed low, high or mixed genetic divergence patterns. The analysis of haplotype networks revealed unexpected intraspecific complexity at the Italian, Palearctic and Holarctic scale, possibly indicating the occurrence of cryptic species. Overall, this study provides new insights into the taxonomy of odonates and a valuable basis for future DNA and eDNA-based monitoring studies.

First records raise questions: DNA barcoding of Odonata in the middle of the Mediterranean.

We present the results of the first-ever DNA barcoding study of odonates from the Maltese Islands. In total, 10 morphologically identified species were collected during a two-week long expedition in 2018. Eighty cytochrome c oxidase subunit I (COI) barcodes were obtained from the collected specimens. Intra- and interspecific distances ranged from 0.00% to 2.24% and 0.48% to 17.62%, respectively. Successful species identification based on ascribing a single morphological species to a single Barcode Index Number (BIN) was achieved for eight species (80%). In the case of two species, Ischnura genei and Anax parthenope, BINs were shared with other closely related species. The taxonomic status of I. genei is questionable and the phylogenetic relationship between A. imperator/parthenope is not clear. Further studies involving a series of adult specimens collected in a wide spatial range and nuclear markers are necessary to resolve these cases. Therefore, this dataset serves as an initial DNA barcode reference library for Maltese odonates, within a larger project: Aquatic Macroinvertebrates DNA Barcode Library of Malta.

The importance of common and the irrelevance of rare species for partition the variation of community matrix: implications for sampling and conservation.

In community ecology, it is important to understand the distribution of communities along environmental and spatial gradients. However, it is common for the residuals of models investigating those relationships to be very high (> 50%). It is believed that species' intrinsic characteristics such as rarity can contribute to large residuals. The objective of this study is to test the relationship among communities and environmental and spatial predictors by evaluating the relative contribution of common and rare species to the explanatory power of models. Our hypothesis is that the residual of partition the variation of community matrix (varpart) models will decrease as rare species get removed. We used several environmental variables and spatial filters as varpart model predictors of fish and Zygoptera (Insecta: Odonata) communities in 109 and 141 Amazonian streams, respectively. We built a repetition structure, in which we gradually removed common and rare species independently. After the repetitions and removal of species, our hypothesis was not corroborated. In all scenarios, removing up to 50% of rare species did not reduce model residuals. Common species are important and rare species are irrelevant for understanding the relationships among communities and environmental and spatial gradients using varpart. Therefore, our findings suggest that studies using varpart with single sampling events that do not detect rare species can efficiently assess general distributional patterns of communities along environmental and spatial gradients. However, when the objectives concern conservation of biodiversity and functional diversity, rare species must be carefully assessed by other complementary methods, since they are not well represented in varpart models.