Abstract
The relationship between contact chemoreceptors and landing of female moths in the field to find out a suitable place for egg laying is very important to discover a good place for the progeny to live. Chemoreception plays an important role in mediating a diverse range of behaviors, including avoidance. Our research has been conducted to evaluate the activity of the botanical extracts from Ricinus communis (seeds and leaves) against oviposition of Spodoptera littoralis. Four solvents differ in their polarity (petroleum ether, chloroform, ethanol, and water) were used to extract the plant material. The following points were studied: (a) Evaluation the oviposition effect of different extracts against S. littoralis. (b) Effect of plant extracts on the development of S. littoralis. (c) Evaluation of the oviposition activity of plant extracts against S. littoralis and number of egg masses. Results showed that the fixed oils, petroleum ether and chloroform extract from seeds are more effective to anti-oviposition activity than water extract. Water and alcohol extract are more effective than leaves volatile oil as anti-oviposition. On the other hand macerated plant of Nerium oleander caused the highest number of egg masses and makes a good stimulus to oviposition. The type and concentration of extracts by water, ethanol, chloroform and petroleum ether were affected on the sex ratio and development of S. littoralis. In general, the biological activity of Ricinus communis extracts was solvent type-and concentration-dependent.
Key words: Key words – Spodoptera littoralis, oviposition behaviour, oviposition deterrence, castor oil, contact chemoreceptors.
CORRESPONDANCE:
Ibrahim A. Gaaboub
E-mail: iaiag@hotmail.com
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