Effect of Bermuda Grass Cynodon dactylon Extracts on Cotton Leaf Worm, Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae)

Abstract

Bermuda grass, Cynodon dactylon (L.) extracts were tested on cotton leaf worm, Spodoptera littorals (Boisd.). Five solvents were used in preparing of these extracts, (i.e., methanol, petroleum ether, acetone, diethyl ether and distilled water). Distilled water was used as polar solvent. The results showed that extracts of non polar solvents were more effective than water. Methanol extract resulted in highest number of giant larvae. Methanol and diethyl ether extracts resulted in the highest number of deformed pupae. Acetone extract caused highest number of mortalities, followed by diethyl ether and methanol extracts. Methanol extract proved to be the most efficient on fertility of S. littorals. All extracts had a slight effect on the larval and pupal stages duration compared with control. Larval and pupal weights were affected in the same manner also. It was concluded that all extracts caused a disturbance in hormonal balance in the larvae.