Observations on adult Culicidae in a rice field of the Ribeira Valley, S. Paulo State, Brazil

Abstract

A collection of adult Culicidae was carried out during the period from May 1984 to September 1985, in a rice field in the polder of the Experimental Station of Pariquera-Açú, in the Ribeira Valley (S. Paulo State, Brazil). CDC miniature traps, supplemented with dry ice, were used. A total of 2,686 mosquitoes were collected. The most frequent were the Coquillettidia and Mansonia genera (nearly 55% of the specimens caught). Aedes scapularis,as an isolated species, contributed with near by 11% of the total catch. Culex (Melanoconion) represented almost 24% of the mosquitoes caught. The sequence of events involved in the flooding of rice seems be associated with the production of Coquillettidia and Mansonia. Ae. scapularis seems to profit from the artificial ecotope represented by the irrigated rice field as a means by which to increase its adaptation to the artificial human environment. No evidence was obtained on the association between Culex (Melanoconion) catches and the cultivation of the rice field. It seems that cultivation exercises no influence on the local Anopheles and Psorophora species.