Estimating numbers and survival of house flies (Diptera: Muscidae) with mark/recapture methods.

Abstract

Two applications of the Jolly–Seber model were used to estimate numbers and survival of house flies, Musca domestica L. The multi sample, single-recapture census, using reared, marked flies and capture by baited jug-traps, was used to estimate numbers of adult house flies in a two-story, high-rise, caged-layer poultry house. Density estimates ranged from 1.2 to 11.5 flies per m2 and had coefficients of variation of 0.12–0.52. Daily survival rates (proportion of population which did not die or emigrate during the interval between samples) were 0.19–0.66 per day. The multisample, multirecapture census, using marked native flies and capture by netting, was used to estimate numbers and survival of house flies in a screen-sided, narrow caged-layer poultry house. Estimated fly densities ranged from 24.8 to 1,159.6 flies per m2 with coefficients of variation of 0.03–0.48. Daily survival rates were 0.54–0.99 per day. Survival rates in both studies declined with increasing mean daily temperature (°C)and on average were 0.32 lower in the high-rise house due to effects of dispersal and predation. House fly survival was not affected by marking with oil-soluble dyes, and capture of house flies using the baited jug-trap was not influenced by age, sex, or marked status of the flies. Assumptions in both census methods are discussed and shown to be met under conditions of these experiments.