Transcriptome-based phylogenomic analysis reveals evidence of ancient hybridization events in the Mepraia genus (Hemiptera: Reduviidae: Triatominae)

IntroductionThe Mepraia genus is composed of three endemic species in Chile, namely Mepraia spinolai, Mepraia gajardoi, and Mepraia parapatrica, all capable of transmitting the causative agent of Chagas disease. Although species divergence within this genus is supported by morphological, molecular, and geological evidence, it has never been validated by genome-wide data.MethodsIn this sense, a pioneering phylogenomic study was conducted using transcriptome data of the three species, aiming to infer robust phylogenies and evaluate the impact of interspecific gene flow on the evolution of these insects. Our transcriptomes were used to robustly infer the phylogenetic relationships, employing multi-species coalescent and supermatrix approaches, as well as to investigate the occurrence of introgression.Results and discussionThe inferred phylogenies support the monophyly of the three described taxa and infer divergence times, although gene trees display high levels of discordance. Our results indicate widespread introgression among Mepraia lineages. Thus, our results support that Mepraia diversification occurred in a short period resulting in reticulate phylogenies and low genetic diversity. Additionally, we obtained evidence of introgression suggesting that ancient hybridization has had a major role in the evolution of the three Mepraia species

Characterization of Female External Genitalia and Eggs of Four South American Species of the Triatoma Laporte, 1832 Genus (Hemiptera: Reduviidae: Triatominae)

Triatoma is the most diversified and one of the most important genera from an epidemiological perspective. Given the difficulty in identifying some species of the Triatoma genus, morphological, histological, and morphometric studies were performed to provide new characters that make it possible to differentiate T. garciabesi, T. guasayana, T. patagonica, and T. sordida sensu stricto, triatomines that overlap geographically and have vector potential. Through the external female genitalia, as well as morphology, morphometry, and histology of eggshells, it was possible to discriminate the four species. In addition, this study reinforces the taxonomic validity of T. garciabesi and provides new data for discussion on systematic issues of T. guasayana and T. patagonica

Biological aspects of Rhodnius montenegrensis (Hemiptera, Reduviidae, Triatominae) under laboratory conditions

Triatominae are insects notorious as vectors of Trypanosoma cruzi, which is the etiologic agent of Chagas disease, and other trypanosomatids. Triatomines of the genus Rhodnius are primarily sylvatic, nevertheless the occurrence of native species that invade households suggests their possible role in the transmission of Chagas disease. Rhodnius montenegrensis was first described in 2012, but the biological aspects of this species are still unknown. This study aimed to analyze the biological aspects of R. montenegrensis under laboratory conditions. The emergence rate was 63.0%, the mean time required for the emergence was 13.9 +/- 1.7 days, the biological cycle from egg to adult phase occurred in 105.2 +/- 9.2 days, the number of bloodmeals required for each nymphal stage to reach the next stage varies between a minimum of two and a maximum of seven. The weight gained after a bloodmeal varied between 10.6 times on 1st-instar nymphs and 3.9 times on 5th-instar nymphs. The adult specimens had the lowest gain of weight, reaching 2.2 times on females and 1.6 times on males. The sex ratio observed was 1:1. These data are relevant to understand the life cycle of this new described species and to elaborate more effective vector control strategies1912929932sem informaçãosem informaçã