Contributions to the Taxonomy of Bretfeld and Yosii (Collembola, Symphypleona, Appendiciphora), with the Description of New Species from Northeastern Brazil.

Bretfeld is a small genus of Neotropical Bourletiellidae, with only four described species so far. Yosii is a widespread taxon of Dicyrtomidae, with most species known from the tropics. Here, we describe two new species from northeastern Brazil: sp. nov. and sp. nov. We also provide a detailed chaetotaxic study for for the first time, with updated diagnoses and identification keys for the Neotropical species of both genera and notes on their morphology. sp. nov. resembles Arlé in body color pattern, male head and dental chaetotaxy. The discovery of one bothriotrichum-like sens on the large abdomen of the new species needs to be investigated as a possible generic diagnostic feature, but we suggest that this structure is homologous to the S-sens seen in at least four Bourletiellinae genera, and they are likely related to each other. sp. nov. belongs to the -group and resembles Reuter and Nayrolles and Betsch in some aspects of the head, dental and abdominal chaetotaxy. These descriptions represent the first record of from Caatinga and the first nominal species of from Brazil.