Heeflumuron, chlorfluazuron and flufenoxuron were laboratory tested for their efficacy against larvae of the spiny bollworm, Eadas Insukma (Bolsd.). The compounds were incorporated at different concentrations in artificial diet. One-day-old and five-day-old larvae were introduced to the treated diets until pupation and adult emergence. Results obtained indicated that hexaflumuron was active at 0.5, 0.25 ppm and 0.75, 0.5 ppm against one and five-day old larvae, respectively. At the same larval instars, chlorfluazuron was active at 0.75, 0.5 ppm and 1.5, 0.75ppm, respectively. Hufenecuron was active at 0.75, 0.5 ppm to one- and five day old larvae. The results revealed that, one-day old larvae were more susceptible to all tested compounds than five-day old larvae, when cotton bolls were dipped in the compounds. Results showed that only 3 % and B % of the larvae penetrated inside the bolls with 0.5 and 0.75 ppm of heeflumuron, respectively; while 75 % penetrated Inside the untreated bolls.