Diel Host-Seeking Activity of Adult Diachlorus ferrugatus (F.) (Diptera: Tabanidae) in Northwestern Florida

Host-seeking activity of adult Diachlorus ferrugatus (F.) was studied in northwest Florida during its peak abundance period in June 1993 and 1994. Primary peak activity occurred at sunset (1945h Central Standard Time) with a minor secondary peak at 1145h. Temperature explained the major portion of variation in host-seeking behavior with relative humidity and light intensity as statistically non-significant factors. No host-seeking activity was observed at darkness. Mark-recapture studies indicated that the majority of individuals did not remain in the area after initial capture but were transitory. Anthrone assays from D. ferrugatus collected adjacent to the immediate study area revealed that about 72% had fed on fructose, while parity assays indicated 96.9% of host-seeking adults were nulliparous.