PHYSIOLOGICAL DISORDERS OF THE COTTON LEAFWORM SPODOPTERA LITTORALIS (BOISD.) FED ON CERTAIN PLANTS AND SYNTHETIC MEDIA

Abstract

Anti feeding or deterrent effects of bestachia and dumb cane towards Spodoptera littoralis (Boisd.) larvae were evaluated. Extracting these plant bio-compounds was carried out by water or organic solvents; i.e. methanol, chloroform or hexane. Castor bean leaves (which are highly acceptable to larvae) were dipped in extracted solutions and offered to second or fourth instar larvae. Second instar larvae were more sensitive than older instars as insects showed relatively poor growth and the interrnolt was markedly prolonged in consecutive instars, also, a high rate of mortality was recorded