PROC. BIOL. SOC. WASH. 92(4), 1979, pp. 697-718 A NEW GENUS OF WATER BEETLE FROM AUSTRAL SOUTH AMERICA (COLEOPTERA: HYDROPHILIDAE) Paul J. Spangler Abstract. — Descriptions and illustrations are given for the adult, larva, and pupa of a hydrobiine water beetle, Anticura flinti, new genus, new species, collected from Chile and Argentina. These forms are interpolated into existing keys. Pupation, habitat, collecting methods, and behavior are discussed. The adults are the first hydrophilids known to have dimorphic metathoracic wings and this condition is also discussed. A single female of this new genus was collected in 1974 from San Martin de los Andes, Argentina, by my colleague Dr. Oliver S. Flint, Jr. Although the temptation to describe the genus on the basis of the single female was strong, it seemed prudent to wait for more material; so the female was put aside until, hopefully, more specimens of both sexes could be obtained. In this instance patience was rewarded. The habitat of the single specimen collected by FHnt was not known with certainty. Dr. Flint was collecting larvae and adults of Trichoptera from a small fast flowing stream when he collected the beetle, and it seemed prob-able that the specimen was found in piles of partly submerged driftwood or logjam habitats in the stream or at the margin of the stream. This type of habitat is similar to those in which we sometimes find Ametor latus (Horn) and A. scabratus (Horn) in the northwestern United States, Sperchopsis tessellatus Ziegler and Hydrobius melaenus (Germar) in the eastern United States, and Hydramara argentina Knisch in northwestern Argentina. There-fore, when the recent opportunity became available to go to Chile to par-ticipate in fieldwork in the mountains on the Chilean-Argentinian border, a search for this beetle was a first priority. Our work was centered in the region around Anticura in Puyehue National Park in Osorno Province. There we encountered dry weather which reduced stream flow in local streams and made collecting in them easy. The cold, cloudy, and misty mornings usually turned to warm, clear days by noon, and the surrounding mountains, volcanos, forests of Nothofagus, and the cold clean trout streams added to the esthetic pleasures of collecting in this area. A small stream, the Rio Anticura, flowed through the park and appeared to be a good one in which to search for the undescribed genus if it indeed occurred in this area. There-fore, I was delighted to discover a single hydrophihd larva in a logjam during
BioStor
