Zum Einfluß der Populationsdichte auf die Nachkommenproduktion der Getreidehähnchen (Oulema spp.).

Abstract

The influence of the density of population of the reproductive faculties of cereal beetles (Oulema spp.) was analysed on the basis of model experiments made by putting given numbers of insects into Mitscherlich vessels with 15 plants of wheat or barley. With increasing numbers of insects the oviposition per female was significantly reduced. Also for the larval stage clear correlations could be established. The production of offspring with 25 insects per vessel was finally reduced by a lower fertility of the females and a higher mortality in the larval stage by 84% as against 2 individuals per vessel.