Emergence dynamic of Parachironomus supparilis Edwards, 1931 (Diptera, Chironomidae) from phytofauna of Cabomba piauhyensis Gardney, 1844

Parachironomus supparilis is a neotropical species with large occurrence in all South America. Although the genus has received detailed taxonomic review, scarce have been the works with an ecological aim, mainly those referring to the numeric dynamic and to emergence patterns. The aim of this paper is to analyze the phenologic dynamic of P. supparilis, an important species of the phytophilous fauna of different aquatic macrophytes of lentic environments. A monthly sampling program of Cabomba piauhyensis (Nymphaeaceae) was established from an ox-bow lake of the Mogi-Guaçu River (Infernão Lake), situated at Jataí Ecological Station (Luiz Antônio, SP). The same volume of the macrophyte were collected monthly and placed in a plastic tray and the emergent adults were caught daily, during 30 days in the laboratory for thirty days to collect emergent adults. P. supparilis contributed with 22.6 % of total Chironomidae collected in the period from Apr/96 to Jun/97. With an average numeric density of 39 male adults/10g dry weight of C. piauhyensis, and with major emergence in the periods of low temperature and precipitation, the species showed greater intensity of emergence in the months of Aug/96 (84 ind./10g) and Jun/97 (75 ind./10g). The presence of adults during the whole period of study seems to indicate that the species is multivoltine, with continuous reproduction.

Phenologic dynamic; Nymphaeaceae; Parachironomus; Infernão Lake

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