On the host preference and biology of the cotton leaf worm Spodoptera littoralis Bois

The larvae of Spodoptera littoralis fed on a wide variety of plants. Of 27 plant species belonging to 16 families used in acceptance and support of growth test, 8 were refused, 5 were eaten to some extent and 14 supported growth. No generalization could be made relating the acceptability of the host plant and its taxonomic position. Laboratory studies were carried out to investigate the effect of host plants on the biology of the cotton leaf worm. Host plants showed variable effects on the duration of different developmental stages, weight of the pupae, as well as the reproductive capacity and fertility of eggs. Castor oil leaves shortened the larval and pupal duration, while sweet potato prolonged it. Host plants may be arranged in an ascending order with respect to the pupal weight as follows: sweet potato, pepper, cotton, sesban and castor oil leaves. Sesban, castor oil and sweet potato favoured larvae to produce moths of high egg potential. The fertility of the eggs is affected as well. Zusammenfassung Zur Wirtspflanzenbindung und Lebensweise von Spodoptera littoralis Die Wirtspflanzenbindung von Sp. littoralis wurde getestet. Von 27 dargebotenen Pflanzenarten, die zu 16 Familien gehoren, wurden 8 abgelehnt, 5 bedingt und 14 voll angenommen. Nur letztere ermoglichten die volle Entwicklung. Beziehungen zwischen Wirtsbindung des Schadlings und Systematik der Wirtspflanzen bestanden nicht. Die Entwicklungsdauer der Raupenstadien, das Puppengewicht sowie die Zahl befruchteter Eier wurden von der Wirtspflanzenart beeinflust. Insbesondere fuhrte die Ernahrung der Larven mit Rizinus sesban und Suskartoffeln zu einer Erhohung der Eiproduktion der Falter.