Time and weather effects on daily feeding patterns of stable flies (Diptera: Muscidae)

Hourly counts of stable flies Stomoxys calcitrans , feeding on cattle, and concurrent weather measurements, were used to describe daily feeding patterns and to estimate effects of temperature, radiation, wind, and humidity on feeding responses. Daily feeding patterns in Nebraska were consistently unimodal, with maximum rates occurring at midday. In the prevailing summer conditions, flies appeared to engorge once or less per day, and feeding rates were partially determined by time, regardless of weather. Several methods were developed for estimating daily cumulative feeding rates for unimodal patterns from one or more independent counts of feeding flies. Consideration of time improved precision of estimates by a factor of four. Effects of weather were estimated by a function, H, which expressed feeding rates in proportion to numbers of flies that had not previously fed during the day.