Biting behaviour of saltmarsh deer flies (Diptera: Tabanidae)

During studies in a salt marsh in Connecticut it was found that the biting cycle of Chrysops atlanticus Pechuman is bimodal. The first main biting period started shortly after sunrise and lasted about 3 h, and a second less intense period of biting began about 2 h before sunset and terminated shortly before sunset. Chrysops fuliginosus Wied. had a single peak in its biting cycle. The main biting period began in late morning and continued for about 3 h. On man, C. atlanticus landed on all parts of the body, but preferred the upper parts, particularly the back of a person walking at a slow pace. Under similar conditions, C. fuliginosus landed mainly on the head and back of the neck. On a seated man, C. atlanticus readily landed on the lower parts of the body. Both species bit man, but each had difficulty ingesting blood. This trait encourages each species to bite intermittently. The incidents of attacks by these two species was much higher in wooded areas than in adjacent open areas.