A new species of Hydrogamasellus (Acari: Mesostigmata: Ologamasidae) from Brazil, with a key to the world species of the genus

Hydrogamasellus alagoensis n. sp. is described based on the morphology of adult females and males collected from litter in the State of Alagoas, Brazil. Six new combinations are proposed, namely Acugamasus avium (Karg, 1976) n. comb., Ologamasus lanceolatus (Karg, 1976) n. comb., Ologamasus microcrinis (Karg, 1979) n. comb., Ologamasus testudinis (Karg, 1976) n. comb., Rykellus longopilus (Karg, 1976) n. comb. and Rykellus ubatubaensis (Hirschmann, 1966) n. comb., and a key for the separation of females of the eighteen recognizable world Hydrogamasellus species is provided.

We thank the Brazilian CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) for the scholarship to the first author. We are also grateful to FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) for the postdoctoral fellowship to Raphael de Campos Castilho (Process 2011/18971-7). We are especially grateful to Bruce Halliday (CSIRO, Australia) and Carlos Flechtmann (ESALQ/USP, Brazil), for their valuable suggestions. This work is part of BIOTA/FAPESP project (Process 2010/52342-4) and CNPq (Process 563233/ 2010-9).