Abstract
Austrolimnius cleidecostae sp. nov. is one of the smallest species of Elmidae from the Neotropical region. The new species is described and illustrated based on male and female specimens. This species represents the first record in Elmidae of mandibles with an articulated, sclerotized process on inner subapical edge. The specimens were collected from streams in the Atlantic rainforest of São Paulo and Santa Catarina, and habitat notes are given. An updated key for the AustrolimniusCarter & Zeck, 1929Carter, H.J. & Zeck, E.H. 1929. A Monograph of the Australian Dryopidae: Order Coleoptera. Australian Zoologist, 6, 49-72 + i-vii. of Brazil is provided. Austrolimnis browniHinton, 1971Hinton, H.E. 1971. Some American Austrolimnius (Coleoptera: Elmidae). Journal of Entomology Series B, Taxonomy, 40(2): 93-99. and A. musgraveiHinton, 1939Hinton, H.E. 1939. A note on the genus Austrolimnius C. & Z., with a description of a new species from French Guiana (Coleoptera, Elmidae). Proceedings of the Royal Entomological Society of London, 8(10): 195-199. are recorded for the first time from Brazil.
Key-Words.
Aquatic beetles; Streams; Neotropical; South America; Taxonomy
