Diel host-seeking activity of Chrysops celatus (Diptera: Tabanidae) in northwest Florida

Diel host-seeking activity of adult C. celatus was studied in northwestern Florida, USA, during June 1993 and 1994. A total of 521 females was collected using aerial insect net sampling over human bait. Primary peak activity occurred at 06.45 h (Central Standard Time) with a secondary peak at 19.45 h. Host-seeking behaviour was correlated with relative humidity but not temperature and light intensity. No host-seeking activity was observed at darkness. In all studies, the majority of flies initially marked and released were not recaptured in the area. Anthrone assays from C. celatus collected adjacent to the immediate study area revealed that >96% had fed on fructose, while parity assays indicated about 92% of host-seeking adults were nulliparous.