IMPACT FACTORS OF TWO NON-CONVENTIONAL COMPOUNDS ON Spodoptera littoralis (BOISD.)

Abstract

Cotton Leaf worm, Spodoptera littoralis (Boisd.) treated as 4 th instar larvae by two compounds of acetyl salicylic acid (A.S.A) and chlorpheniramine maleate (C.P.M) to evaluate its efficacy on S. littoralis larvae as alternative new compounds for insecticides. Also, some biological and life table parameters of S. littoralis treated as 4 th instar larvae were estimated. In addition, S. littoralis moths treated by LC 50 of A.S.A and C.P.M to evaluate the mating frequency & ability and batches fluff cover shape deposited by moth in different treatments (T♂xT♀, U♂xT♀, T♂xU♀ and U♂xU♀). Obtained results could be summarized as following: Tested compounds of A.S.A and C.P.M were efficacy on S. littoralis larvae, but C.P.M was more toxicity and effective on the most estimated parameters than another compound (A.S.A). Compounds of A.S.A and C.P.M had increased in larval & pupal mortalities, control of hatchability and sterility; also, tested compounds decreased the pupation, moth's emergency, number of eggs per female, egg hatchability and fecundity of S. littoralis treated as 4 th instar larvae. In addition, its caused decreasing in mating frequency and ability of different crosses moth and the batches deposited without fluff covers and the egg-masses had unstable partly on the deposited surface until hatching, especially in T♂xT♀ treatments. Moreover, the two tested compounds, especially C.P.M had drastically decreased the life table parameters as number of females/female (Mx), survival rate (Lx), net reproductive rate (Ro), intrinsic rate of natural increase (r m), and finite rate of increase (e rm). Aforementioned compounds had increased from generation (T) and doubling (DT) times. So, A.S.A and C.P.M are considered affecting compounds against two harmful stages (larvae and moths) of S. littoralis, especially C.P.M, that it could be used to reduce the insecticide applications but need more experiments in a wide range.