Integrative taxonomy of morphologically indistinguishable species of the genus Psychodopygus (Diptera, Psychodidae), Chagasi series, registered in Brazil

Author(s)

Rodrigo Espíndola Godoy

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Saúde Pública (FSP/CIR)
• Defense date: 2018-06-25

Examining board members

Eunice Aparecida Bianchi Galati; Andrey José de Andrade; Silvio Shigueo Nihei; Maria Anice Mureb Sallum

• Advisor: Eunice Aparecida Bianchi Galati

Abstract

Introduction. The identification of sand flies is mainly based on adult morphology, which can be problematic when species are morphologically very similar. Psychodopygus is one of the sand fly genera of great interest in public health, due to the role of some species in the transmission of Leishmania spp. in Brazil. However, this genus includes species with morphologically indistinguishable females that belong to the Chagasi series, which includes: P. chagasi, P. complexus, P. squamiventris maripaensis, P. squamiventris squamiventris and P. wellcomei. Objectives. To investigate the possibility of distinguishing among these species by means of morphometric and molecular analyses in addition to producing an updated geographical distribution for the group, analyzing the probability of the occurrence of the species by the analysis of ecological niche modeling. Material and methods. The analyses of the cytochrome c oxidase subunit 1 (COI), geometrical (head and wing) and of linear morphometry and morphology (using optical microscopy and scanning electron microscopy) were carried out using a total of 752 specimens (460 females and 292 males) from the following states: Amapá, Amazonas, Ceará, Mato Grosso, Pará, Rondônia, Roraima e Tocantins. Distribution maps were produced on the basis of data obtained from the material analyzed and a bibliographical review. Results. The discriminant analysis using linear morphometric characters was able to differentiate among all the species, except for P. complexus, which presented a 2.2% error of identification. The geometric morphometry of the wings was unable to completely separate the species by means of the shape analyses, but the centroid size of the female specimens only failed to distinguish P. complexus from P. s. maripaensis. Otherwise, the geometric morphometry of the heads was sufficient to distinguish all the species with great efficiency, when using both the head-shape and the centroid size. The morphological analysis revealed that the thoracic coloration, mainly of the pronotum and the post-notum, can be used to separate the five species into three groups: P. chagasi, P. wellcomei / P. complexus, P. s. mariapaensis / P. s. squamiventris. The results of the Barcoding DNA analyses showed a cluster similar to that observed in the morphology; however, P. wellcomei specimens from the Ceará population showed a great genetic distance from the population of Pará, evidencing that this species may represent a complex. As for the scanning electron microscopy, the structures of the antennae, thorax and male genitalia were evaluated in detail. In the anepimerum (thorax) a modified \"racket\"-type scale was observed only in Psychodopygus s. squamiventris. The review of the geographical distribution showed that the species have a cis-Andean distribution, occurring mainly in the Amazonian biome. The separation of some species from the others by the Amazon river suggests that the appearance of the Chagasi series occurred in the period from the orogenesis of the Andes to the formation of this river. Conclusions. The results clearly differentiate the females of the five species of the Chagasi series using the data set of linear and geometric morphometry and morphological analyses, providing new morphological and distributional data that will facilitate the identification of the males and females of this group. (AU)

• FAPESP's process: 15/02282-9 - Taxonomic study of sandflies of the genus Psychodopygus (Mangabeira, 1941) chagasi series (Barretto, 1962) through morphometric, morphological and barcoding analyzes
• Grantee: Rodrigo Espíndola Godoy
• Support Opportunities: Scholarships in Brazil - Doctorate