—The community structure and diel activity patterns of peridomestic Stomoxyinae at two locations in Nairobi and its outskirts (Chiromo and Ruiru) were studied using Nzi traps baited with octenol. Six species of Stomoxys (S. calcitrans, S. niger niger, S. n. bilineatus, S. inomatus, S. taeniatus, S. varipes) and three other Stomoxyinae genera (Haematobosca, Stygeromyia, Parastomoxys) were caught. At Chiromo, species diversity (H') varied from 0.29 to 0.65 and evenness from 0.59 to 0.83, whereas at Ruiru, diversity varied from 0.0 to 0.38 and evenness from 0.0 to 0.46. Diurnal activity both S. calcitrans and S. n. niger was bimodal, with a small peak of activity in the morning (0800–1100 hrs) and a major peak in the evening (1700–1800 hrs). Both species showed a midday depression in activity. The activity of S. inomatus rose steadily throughout the day with only a slight midday depression. These results are discussed with respect to results of similar studies in a natural, undisturbed habitat.
