Redescription of Dicranocentrus heloisae Arlé & Mendonça, 1982 (Collembola: Entomobryidae)

Abstract

Dicranocentrus heloisae Arlé & Mendonça 1982 is redescribed based on specimens collected from its type locality, "Parque Nacional da Tijuca", Rio de Janeiro municipality, State of Rio de Janeiro. The presence of 6+6 macrochaetae S, 1+1 macrochaeta P, and absence of macrochaetae A1 and Ps dorsally on head, puts Dicranocentrus heloisae in the gracilis-group sensu Mari-Mutt (1979). This species is easily indentified mainly due to general color pattern of pale yellow on body with bluish to blackish pigmentation on head. Taxonomic characteristics not illustrated in the original description are given (dorsal cephalic chaetotaxy, sensory organ of the third antennal segment, eyes, labrum, maxillary palp, outer labial papilla, labial triangle, trochanteral organ, femur, tibiotarsus, unguis, ventral tube and tenaculum). New records from other localities in Brazil are provided. A neotype for Dicranocentrus heloisae is designated.

A Survey of the Brazilian Dicranocentrus Schött (Collembola, Orchesellidae, Heteromurini) with the Description of a New Species and Notes on the Genus

“…Dicranocentrus heloisae typically has 5 mac on Abd. I [ 18 ]; however, it was reported in specimens also with 3 [ 21 ]. Here, we disregard such observations, since it is possible that specimens of D. heloisae with 3 mac on Abd.…”

“…Concerning the morphology of Brazilian species, D. albicephalus , D. cuprum , D. heloisae , D. magnus , D. marimutti , D. melinus and D. pikachu were very well studied and described/redescribed by Xisto and Mendonça [ 18 , 20 , 21 ]. Very few diagnostic features are unknown to these species, such as the number of smooth chaetae on furca and trunk sens formula, for example.…”

“…Mari-Mutt’s groups of species based on dorsal head macrochaetatoxy are quite useful for the current taxonomy of Dicranocentrus [ 12 , 17 , 18 , 20 , 21 , 41 , 57 ]. Distribution endorses Mari-Mutt’s groups at some level [ 12 ] (as partially represented in Figure 7 ).…”

“…The genus’ main diagnostic features are antennae with six segments (antennal segments I and II subdivided), 8 eyes, prelabral chaetae simple (not bifurcate), ungues with a single outer tooth and dental spines, if present, simple (a detailed diagnosis is presented in the results topic) [ 12 , 14 , 15 ]. Currently, there are 11 species of Dicranocentrus known from Brazil, found in humid forested areas of Atlantic and Amazon forests domains ( Table 1 ) [ 6 , 13 , 16 , 17 , 18 , 19 , 20 , 21 ].…”