Biting activity patterns of Culex (Melanoconion) ribeirensis in southern Brazil.

The biting activity of Culex ribeirensis was studied in the highland region of Southern Brazil and compared with data previously obtained in a lowland area of the same region. Hourly sampling with human bait showed a bimodal pattern, with a greater peak in the evening crepuscular period. Behavior was similar in both the highland area of Lupo Farm and the lowland of the Ribeira Valley but with a notable feature in the former. In relation to the vespertine crepuscular period, precrepuscular peaks were observed in the highland area. The adaptability of this species to man-made environments and its epidemiological significance are considered.