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 gehören, wurden 8 abgelehnt, 5 bedingt und 14 voll angenommen. Nur letztere ermöglichten die volle Entwicklung. Beziehungen zwischen Wirtsbindung des Schädlings und Systematik der Wirtspflanzen bestanden nicht. Die Entwicklungsdauer der Raupenstadien, das Puppengewicht sowie die Zahl befruchteter Eier wurden von der Wirtspflanzenart beeinflußt. Insbesondere führte die Ernährung der Larven mit Rizinus sesban und Süßkartoffeln zu einer Erhöhung der Eiproduktion der Falter.

Margosan‐O and Neem azal‐S two commercial preparations of neem seed kernel extract were tested for their effect as deterrent, toxicant and growth inhibitor against the two spotted spider mite Tetranychus urticae Koch. Both formulations exhibited strong deterrent effect for T. urticae females. ODI was maximum 100% in case of Neem azal‐S and 80.95% for Margosan‐O at (0.4%) conc. Leaf discs treated with different concs. of the two products showed increased mortality and retarded development. A significant reduction in the total no. of eggs laid as well as a decrease in the percentage of egg hatchability was observed. Zusammenfassung Zur Wirkung von zwei Neem‐Samenextrakten auf die Spinnmilbe Tetranychus urticae Koch Es wurden Margosan‐O und Neem‐Azal‐S, zwei kommerzielle Praparate aus Neemsamen‐Extrakten hinsichtlich ihrer abschreckenden, toxischen und wachstumshemmenden Wirkung auf die Spinnmilbe T. urticae untersucht. Beide Formulierungen zeigten abschreckende Wirkung auf die Spinnmilben‐Weibchen. Der ODI‐Wert betrug 100% beim Einsatz von Neem‐Azal‐S und 80.95 YO bei Margosan‐O (je 0,4% Konz.). Blattausschnitte, die mit verschiedenen Konzentrationen der beiden Produkte behandelt worden waren, zeigten zunehmende Mortalitat und Entwicklungshemmung. Weiterhin wurden signifikante Verminderungen der Gesamtzahl an abgelegten Eiern und der Eischlupfquote festgestellt.

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When eggs of Adalia bipunctata L. are offered to larvae of their own species, these larvae are able to develop to adults. Reducing the daily egg supply results in decreased larval survival and pupal weight and especially fecundity of the adult females. The duration of larval development is significantly increased, the longevity of adults is shortened. Cannibalism on eggs is of wide occurrence in the predaciousCoccinellidae. CLAUSEN (1916) observed that the hatching of the larvae was sometimes protracted in egg batches of Hippodamia convergens GUERIN and that the first larva to hatch attacked the unhatched eggs. i-L~WKES (1920) recorded a similar behaviour in Adalia bipunctara L. and found that about a quarter of the larvae were destroyed before dispersal.BANKS (1956) and HAGEN (1962) observed that A. bipunctata larvae remained clustered together on the empty egg shell for 12-24 hours, in this way cannibalism is favoured.The importance of this kind of cannibalism for the coccinellid population is not quite clear. BANKS (1956), DIXON (1959) and BROWN (1972) stated that the larvae by feeding on eggs are able to make a more prolonged search for aphid food. DIxoN (1959)recorded that the loss of unhatched eggs of Adalia decempunctata L. by cannibalism was of little consequence since most of these eggs were not viable. KoIDE (1962) succeeded in obtaining complete larval development of Coccinella septempunctata by feeding on an exclusive diet of eggs of their own species.The present investigation was carried out to ascertain whether the eggs of A. bipuntata can b'e a full diet for larvae and adults of this species. Using eggs, known quantities of food could be offered(1) Present address: