Abstract
A single-release and repeated-recapture experiment was carried out to (1) evaluate the attractancy of a newly found chemical attractant, 2-phenylethanol, to the onion and seed-corn files, Hylemya antiqua and H. platura and (2) obtain some population parameters and data on the distribution and behavior of these flies in the field. Both onion and seed-corn flies responded to 2-phenylethanol similarly regardless of sex, though males seemed more responsive than females. The distribution of both species was concentrated in the onion field and density in other crops seemed low. Released flies dispersed slowly and the distance of dispersion until capture averaged 19.3 m. Population parameters estimated for the onion fly males, females and both combined were as follows : total populations, 1, 160, 1, 720, 3, 260; daily recapture rates, 10.4%, 7.0%, 7.4% and daily survival rates, 0.48, 0.42, 0.52.
