Female ability to attract males after RNAi knockdown of GPAT was analyzed by using a Y-tube olfactometer with 5 cm internal diameter and 15 cm long arms, set at a 450 angles and 15 cm basal stem. 15 ug of dsRNA (GPAT or EGFP) was injected into the abdominal intersegment membrane of female pupae at 48 h before adult elcosion. Two treatments of newly emerged females were placed at two arms of Y-tube respectively. Newly emerged males were tested in the following olfactometer bioassays: 1) the female injected with GPAT-F1 dsRNA vs the female injected with EGFP dsRNA, 2) the female injected with GPAT-F2 dsRNA vs the female injected with EGFP dsRNA. For each of bioassays, 100 newly-emerged males were tested. The frequency of male making choice was recorded. A Yates corrected Chi-square test was used to determine differences between the frequencies of male choosing different female treatments (RNAi knockdown of GPAT or EGFP control).