Observations on feeding patterns among mosquitoes (Diptera: Culicidae) in the Pantanal, MT, Brazil

The feeding habits of culicids were studied by means of the precipitin technique. The collections were made the Trans-Pantanal highway (MT-060-km 52), at 65 km from the main settlement of the municipality of Pocone, MT, every other month, from December 2002 to December 2003. Trapping was performed using Shannon traps and CDC automatic CO2-based traps from 3:00 p.m. to 9:00 p.m. The following antisera were utilized: bird, rodent, human, horse, cattle, capybara and toad. Of the 2,134 females captured, 1,946 (92,2%) were collected in Shannon traps and 188 (8,8%) in CDC traps. Among these totals, 276 females (13,0%) were engorged and suitable for the precipitin test, of which 235 (85,1%) were collected in Shannon traps and 41 (14,9%) in CDC traps. It was found that 84.2% of the specimens analyzed reacted to one food source and 15.8% to two sources. Mansonia titillans (Walker), Culex nigripalpus (Theobald), Aedeomyia squamipennis (Lynch-Arribalzaga) and Psorophora albigenu (Peryassu) were the most frequently found species, and reacted to all the antisera. On the other hand, few specimens of the anophelines, Anopheles albitarsis (Lynch-Arribalzaga), An. matogrossensis (Lutz & Neiva) and An. triannulatus (Neiva & Pinto), reacted to five antisera. The other species were positive to three up to six antisera. The estimate of the feeding index revealed positive results for eight species, of these five they presented outstanding preference for the host capybara.