Das Körperwachstum bei Blattläusen (Homoptera, Aphididae) als Ausdruck des Nährstoffangebots in der Wirtspflanze. Teil III. Untersuchungen an Blattscheiben von Vicia faba L.

Abstract

On leafdiscs from broadbean (Vicia faba L.) nutritive effects of the host plant on the postnatal development of the black bean aphid, Aphis fabae Scop., is demonstrated. Weight gain (mg x) of six days old apterous exules was used as a criterion for growth. Progress in aphids' body weight depends on amounts of free nitrogen and carbohydrate metabolits in the nutritive substrate. High contents of preformated protein and starch in leafdiscs leaded to an increase of essential low molecular compounds (amino acids, amides, sucrose etc.) and as a consequence an acceleration in body growth of aphids occured. Manipulation of protein and starch contents by changing temperature and light effects on the host during its larval period caused different and heavy responses of body weight progress of aphids. The possible controlling physiological factors in the host are discussed. An experiment demonstrates, that the average weight of aphids seems to be a suitable indicator for the actual protein and starch status in the leaves of the host plant in the course of its ontogenetic development.