RESUMEN
The objective of this study was to evaluate the effectiveness of imidacloprid (Q-Bayt®) against the Kundang and WHO 213 strains of the female housely Musca domestica. By scatter application of 4.0 g Q-Bayt®, after 24 hours, the mortality rates for the Kundang strain and WHO 213 were 36.7 and 54.4%, respectively. At 48 hours’ exposure to Q-Bayt®, the mortality of M. domestica Kundang strain increased to 63.3% and WHO 213 to 73.3%. By paint-on application with Q-Bayt® at 1.5 g/ml, after 24 hours the Kundang strain and WHO 213 showed 38.9 and 48.9% mortality, respectively, whereas 75.6% was obtained for the former and 77.8% for the latter at 48 hours’ post-treatment. On the whole, Student-t test and Mann-Whitney test showed no significant difference (p \> 0.05) in mortality rates between the two strains, with either scatter or paint-on application. Thus, Q-Bayt® is a potential insecticide for controlling the housefly M. domestica. With regard to the dosage used and mortality rates obtained, paint-on application was more efficient than scatter.