Comparative analysis of the dorsal chaetotaxy of Troglopedetes, Trogolaphysa, and Campylothorax supports the synonymization of tribes paronellini and troglopedetini (Collembola: Paronellidae)

Abstract

Genera in subfamily Paronellinae have been grouped into five tribes, in part based on chaetotaxy. Tribes Bromacanthini, Paronellini, and Troglopedetini are characterized by having rounded scales and reduced or no macrochaetae, and although Bromacanthini harbors two well-differentiated genera, the core genera in tribes Paronellini and Troglopedetini form a homogeneous group where even generic diagnoses were, until recently, unclear. The genera assigned to Troglopedetini (Troglopedetes Absolon, Trogolaphysa Mills, and Cyphoderopsis Carpenter) harbor many species with reduced eyes number, whereas the tribe Paronellini (genera Paronella Schött, Dicranocentruga Wray and Campylothorax Schött) includes species with 6-8 eyes. Recent analyses of the chaetotaxy of Trogolaphysa and Cyphoderopsis suggest that these genera represent specialized forms related to species in Paronellini. The taxonomy of Troglopedetes, the type genus of Troglopedetini, is based almost exclusively on claw and mucro shape and dorsal macrochaetae pattern, and few details of the complete dorsal chaetotaxy of the species are known. This contribution presents a comparative analysis of the complete dorsal chaetotaxy of two species of Troglopedetes from Spain (one new to science), two new species of Trogolaphysa from the Dominican Republic and Martinique, and Campylothorax sabanus with the purpose of identifying aspects of the chaetotaxy that could provide diagnostic characters for the separation of Trogolaphysa and Troglopedetes, and a new diagnosis for tribe Troglopedetini. The analysis shows that neither the number of chaetae nor its organization or pattern of macrochaeta provides diagnostic differences between Trogolaphysa and Troglopedetes. It is also concluded that the separation of Paronellini and Troglopedetini is not justified. Troglopedetini is here synonymized with Paronellini, and a new diagnosis of Paronellini is provided.