In a laboratory flight tunnel bioassay, optimum attraction of female papaya fruit flies,Toxotrypana curvicaudaGerstaecker, to the sex pheromone 2,6-methylvinylpyrazine was obtained at release rates of 550–1,650 ng/h. Females became responsive to sex pheromone on the fifth day after eclosion, with response peaking on seventh and eighth days postemergence, coincident with ovarian maturation. Responses to pheromone did not decrease qualitatively or quantitatively after mating. A diel pattern to pheromone response was observed with a midday (5- to 7-h into a 12-h photophase) response period for mature, unmated papaya fruit fly females and a broad afternoon response period for mated females.