Three commercial formulations derived from Azadirachta indica (Neem), Citrullus colocynthis (Hanzal) and Thymus vulgaris (Zaatar) were bioassayed individually against 1st instar larvae of spiny bollworm, Earias insulana (Boisd.) to compare their effect on the different biological aspects of the larval, pupal and adult stages. The data obtained indicated that the plant extracts tested with two concentrations (5 and 10 %) adversely affected the mortality of larval and pupal stage (57.33 & 50.67 %), (45.33 & 66.66 %) and (49.33 & 57.33 %), respectively comparing with (2.34 %) in control and significantly decreasing in pupation percentage and influenced on pupal mortality. In addition, proved that larval and pupal weight gains didn't significantly differ from that recorded at the concentrations. Also, results indicate that three tested extracts inhibition the percentages of adult emergence resulted from treated larvae in the two tested concentrations. Results also, caused significantly decreasing numbers of laid eggs. The respective numbers are (54.00 & 0.00 eggs / ♀); (71.66 & 28.00 eggs / ♀) and (22.66 & 84.67 eggs / ♀), respectively compared with (213.33 eggs / ♀) in control. Significant effects on the hatchability percentages of eggs were recorded as follows: (59.26 & 0.00 %), (75.51 & 51.79 %) and (87.72 & 66.62 %), respectively comparing with (90.18 %) recorded in control treatment