Differences in forest use and colonization by Neotropical tree‐hole damselflies (Odonata: Pseudostigmatidae): Implications for forest conversion

The use of Odonata species for environmental assessment: a meta-analysis for the Neotropical region

The order Odonata has been regularly used as an indicator of the ecosystem's condition. The objective of this review was to analyze the importance of Odonata for environmental assessments (assessment types, statistical approach, life stages, and sampling method, or particular metric), summarizing the current state, the trends, and identifying related research issues in the Neotropical region. Therefore, we selected 62 articles from 2007 to 2018 based on published research to monitor Odonata assessments in the Neotropical region. We compiled a database and ran statistical analyses for the observed frequencies. We found that ecosystem health was the most frequent assessment type and quality the most used objective. In the case of statistical tests and metrics, multivariate analyses and species richness were most used in these papers. However, because there is a great diversity of habitats in this region, there is no unique monitoring protocol to assess the quality of ecosystem health and it is needed to create a proposal for a standard evaluation protocol. Consequently, guidelines for monitoring are presented, and we suggest three stages to establish a specific protocol for each site, which records the set of species most sensitive to the exchange rate evaluated, as well as the use of rarefaction methods, the index of diversity based on the area under the curve, and multivariate analysis, among other recommendations.

Transcriptome profiling with focus on potential key genes for wing development and evolution in Megaloprepus caerulatus, the damselfly species with the world's largest wings

The evolution, development and coloration of insect wings remains a puzzling subject in evolutionary research. In basal flying insects such as Odonata, genomic research regarding bauplan evolution is still rare. Here we focus on the world's largest odonate species-the "forest giant" Megaloprepus caerulatus, to explore its potential for looking deeper into the development and evolution of wings. A recently discovered cryptic species complex in this genus previously considered monotypic is characterized by morphological differences in wing shape and color patterns. As a first step toward understanding wing pattern divergence and pathways involved in adaptation and speciation at the genomic level, we present a transcriptome profiling of M. caerulatus using RNA-Seq and compare these data with two other odonate species. The de novo transcriptome assembly consists of 61,560 high quality transcripts and is approximately 93% complete. For almost 75% of the identified transcripts a possible function could be assigned: 48,104 transcripts had a hit to an InterPro protein family or domain, and 28,653 were mapped to a Gene Ontology term. In particular, we focused on genes related to wing development and coloration. The comparison with two other species revealed larva-specific genes and a conserved 'core' set of over 8,000 genes forming orthologous clusters with Ischnura elegans and Ladona fulva. This transcriptome may provide a first point of reference for future research in odonates addressing questions surrounding the evolution of wing development, wing coloration and their role in speciation.

Aquatic life in Neotropical rainforest canopies: Techniques using artificial phytotelmata to study the invertebrate communities inhabiting therein

In Neotropical rainforest canopies, phytotelmata ("plant-held waters") shelter diverse aquatic macroinvertebrate communities, including vectors of animal diseases. Studying these communities is difficult because phytotelmata are widely dispersed, hard to find from the ground and often inaccessible. We propose here a method for placing in tree crowns "artificial phytotelmata" whose size and shape can be tailored to different research targets. The efficacy of this method was shown while comparing the patterns of community diversity of three forest formations. We noted a difference between a riparian forest and a rainforest, whereas trees alongside a dirt road cutting through that rainforest corresponded to a subset of the latter. Because rarefied species richness was significantly lower when the phytotelmata were left for three weeks rather than for six or nine weeks, we recommend leaving the phytotelmata for twelve weeks to permit predators and phoretic species to fully establish themselves.

The complete mitochondrial genome of the neotropical helicopter damselfly Megaloprepus caerulatus (Odonata: Zygoptera) assembled from next generation sequencing data

Odonata (dragonflies and damselflies) is a small order at the base of flying insects (Pterygota). Resolving family-level phylogenetic relationships within this order receives great attention. Hereby, genetic data already resulted in various changes, which are however still under discussion. Mitochondrial genomes may further enhance such phylogenies. This study presents the complete mitochondrial genome of the Neotropical damselfly Megaloprepus caerulatus based on next generation sequencing (NGS) data on total genomic DNA. The total length comprises 16,094 bp and includes the standard metazoan set of 37 genes together with a 1376 bp long A + T rich (control) region. Gene content, gene arrangement and base frequency are consistent with other odonate mitochondrial genomes. It further contains four intergenic spacer regions, indicating a possible family specific feature for the Coenagrionidae and its close relatives.