Seasonal and meteorological effects on activity of Chrysops variegatus (Diptera: Tabanidae) in Paraguay.

Activity of adult, female Chrysops variegatus was studied for 17 months near Aregúa, Paraguay. The population was sampled by walking along a forest path while swinging an insect net. Results of sampling indicated that this species followed no seasonal pattern of activity. Fluctuation in activity appeared to follow a 13-week cycle. Meteorological effects on activity were studied during 2 weeks of peak tabanid abundance. Temperature, humidity, and wind accounted for 89% of the variation observed during the 23 weeks. Activity of this species observed on a particular day appeared to be the result of the overall population level and meteorological conditions at the time.