The present study was undertaken to evaluate the initial and residual toxicity of Virtu 80% WP (chromafenozide), Nomolt 15% SC (teflubenzuron) and Match 5% EC (lufenuron), as well as their effects on food consumption and growth rate of the 4^th, 5^th and 6^th larval instars of cotton leafworm using field-laboratory experiment. The tested IGRs were sprayed on potato plants in the field and their leaves were collected at four periods to conduct laboratory tests. Larvae were fed on treated leaves for two days and then on untreated leaves for another three days in each period. Data indicated that the tested IGR compounds were high efficiency against the fourth and fifth instars at the first period and gave long residual activity. On the other hand, residual activity of Virtu was more effective than the two benzoylphenyl urea insecticides against the sixth larval instar. The same trend of efficacy of the tested IGRs on the food consumption of the fourth and fifth larval instars was also found in the sixth larval instar of S. littoralis. Mean of consumption indexes of all intervals for sixth larval instar was 0.460, 1.096 and 1.219 for Virtu, Nomolt and Match, respectively, compared to 1.131 in check treatment.  Also, it was found that the tested IGRs were able to suppress the growth rate of tested larval instars to different degrees in comparison to that of untreated control. Data indicated that feeding the different larval instars on treated potato leaves with Virtu compound resulted in high reduction in food consumption and growth rate. On the contrary, the both benzoylurea compounds; Nomolt and Match caused slight reduction in consumption index and growth rate.