PREVALENCE OF ANOPHELINES (DIPTERA, CULIC IDAE) DURING SUNSET IN AREAS OF THE ITAIPU HYDROELECTRIC USINE IN GUAIRA COUNTY, STATE OF PARANA,BRAZIL

Systematic collections of anophelines were conducted from November 199 4 to August 1995 from 18:00 to 20:00 hr using Shannon traps and human- bait along the lake margin which forms the Itaipu Hydroelectric reserv oir, State of Parana, Brazil. Species prevalence was studied at 15 min intervals. Anopheles albitarsis sensu latu and An. galvaoi, were the most frequently collected mosquitoes. A II Anopheles species populatio ns peaked between 18:45 and 19:30 hr: The observations illustrate the existence of a haematophagic activity cycle during the early evening h ours: exogenous stimulus (the beginning of sunset) --> Shannon trap (l ight attraction) --> human bait (haematophagy) --> rest and digestion --> exogenous stimulus --> Shannon trap or surrounding vegetation. The greater abundance of An. albitarsis collected in human-bait and Shann on trap suggests it may be a potential malaria vector in the region.