INSECTICIDAL ACTIVITY OF LOCALLY FORMULATED TAR OIL AS SOLUBLE LIQUID ON THE PINK BOLLWORM, PECTINOPHORA GOSSYPIELLA (SAUNDERS)

Abstract

Crude tar oil was prepared as soluble liquid formulation using wetting and spreading agents alone, acidity modifier alone and mixture of wetting and spreading agents plus acidity modifier in different five formulations, Tar oil (1), Tar oil (2), Tar oil (3), Tar oil (4) and Tar oil (5) in addition of the crude tar oil for controlling the pink bollworm, Pectinophora gossypiella (Saunders) as alternative of conventional pesticides. Toxicity of the prepared tar oils and crude tar oil were determined against egg and newly hatched larvae of the pink bollworm. Latent effects when they used with meduim lethal concentration (LC50,s) on the pink bollworm treated as newly hatched larvae which include % larval mortality, % pupation, % moth emergency in addition larval duration, adult longevity, egg laying rate, % egg hatchability, % fecundity, % control of egg hatchability, % sterility (observed and corrected) compared with untreated. Also their effects on some life table parameters (Speculation) such as The female progeny/female (Mx), Survival rate (Lx), net reproductive rate (Ro), intrinsic rate of natural increase (rm), finite rate of increase (erm), generation period (T) and doubling time (DT)were studied. The result contains three parts as follows: Toxicity of tar oils against PBW Results obtained indicated that tested tar oils especially tar oil (4) was the most toxic formula against eggs since its LC50,s ranged between 1.481 -12.48% depends on egg age, the 1-day old eggs was the most susceptible compared with other egg ages, followed by tar oil (2) and tar oil (5) while crude tar oil showed the least effect. Also, tests of the efficiency of the tested tar oils against the newly hatched larvae were conducted in two periods, after 1-hour and 3-day later. The results showed that LC50,s at 3-day later lower than 1-hour. Tar oil (4) had the most toxicity against newly hatched larvae of the pink bollworm treatments, followed by tar oil (2), tar oil (5), tar oil (3) and tar oil (1), while crude tar oil was the least toxic. Latent effect of the tested tar oils Results indicated that tested tar oils had latent effects similar to insect growth regulator compounds since they caused increase in %larval mortality, decrease % pupation and % moths’ emergency. In addition to increase in % control of egg hatchability and % sterility (observed and corrected). Opposite, there are decreasing in larval duration, adult longevity especially oviposition period, egg laying rate, % egg hatchability and % fecundity. Tar oil (4) showed the highest effect compared with the control.