Correlation between toxic natures of pyrethroid and behavioral response of desert locusts

Optomotor normal visual response of the locust Schistocerca gregaria was compared when injected (between 1st and 2nd thoracic segments) with 10, 5, 2.5 and 1.25 microg/g body weight doses of Permethrin after different intervals of time (just after injection, 10 and 20 minutes). LD50 value for Permethrin was calculated to be 3.0 microg/g. Results are analyzed statistically by t. test and ANOVA technique. It was noticed that there was a significant decrease of vision (P<0.005, Table II) in treated locusts and at the same time Permethrine effect is significantly time related (P<0.05, ANOVA, table III). Correlation between increasing age, weight and increasing toxicity has also been established. The inhibition of neural enzyme Cholinesterase with Permethrin and as a result more accumulation of acetylcholine at nerve junctions and less passage of the transmission of impulses thus less response from the locusts has also been explored and discussed.