COMPARISONS OF SAMPLING METHODS AND SEASONAL ABUNDANCE OF DROSOPHILA-REPLETA IN CAGED-LAYER POULTRY HOUSES

Four sampling methods were compared to determine their practicality an d suitability for detecting population fluctuations of adult Drosophil a repleta, a pest in caged-layer poultry houses. Five caged-layer poul try houses with gutter-flush manure removal systems in Franklin County , North Carolina, U.S.A., were sampled once every 2 weeks over 15 mont hs, from June 1991 to August 1992. The flies were most abundant during the spring and early summer. Visual counts of adult flies resting on the feed troughs in front of cages in the aisles and counts of flies c aught on a sticky ribbon lowered into the gutter used for manure remov al by flushing were more satisfactory sampling methods than using coun ts of flies caught on sticky ribbons carried along the aisles or aspir ator collections from the gutters. For the visual count method, the ef fects of location in the house, within each aisle, and feed trough hei ght were determined; two counts on feed troughs in each of two inside rows of cages were sufficient to measure population changes. For routi ne monitoring of D. repleta populations, visual counts of flies restin g on the feed troughs in the front area of two aisles and catching fli es on sticky ribbons inserted into the rear gutter area are recommende d