Untersuchungen zum Fraβpflanzenspektrum von Sitona lineatus L. (Curcul., Coleopt.)1

Abstract

AbstractInvestigations on the feeding plant preferences of adults of Sitona lineatus L. (Curcul., Coleopt.)Leaf disks of fresh plant material (304 plant species from 75 families of Dicotyledoneae and 19 species from Monocotyledoneae, Gymnospermae and Filicatae) were offered to young adults (max. 4 weeks old) of S. lineatus in preference tests. The feeding results were calculated by means of the scheme shown in fig. 1. The preference behaviour in relation to the taxonomy of the testplants is shown in fig. 2. Nearly all non‐dicotyl plants were refused with the exception of Larix decidua, whereas 102 species of the dicotyls of all subclasses except the Asteridae elicited the feeding; most of the attacked plants belonged to the subclasses Rosidae and Hamamelidae, particularly the orders Fabales and Rosales resp. and Fagales and Urticales, both including nonherbaceous species. The amount of feeding was in addition significantly altered by the seasonal age of the leaves (fig. 3) and on combination of plant species offered together in each experiment. None or only little feeding occured on the other plants, if one of the following species were present: Pisum sativum, Vicia faba, V. sativa. This wide host spectrum and the accompanying strong preference to 3 species of Fabales may be defined “limited‐polyphagous behaviour” or in german “bedingte Polyphagie”. The ecological importance of this type of behaviour is discussed.