Zur Biologie und Massenzucht der Getreidemotte Sitotroga cerealella Olivier, 1879 (Lepidoptera: Gelechiidae). 2. Beitrag: Beobachtungen am Larven- und Imaginalstadium.

Abstract

Behaviour and performance of egg larvae and moths of Sitotroca cerealella Olivier, 1789, are reported. Studies on the influence of the food of the larvae on mortality and fertility of the moths showed under equal test conditions that the total obteinable egg yield compared with barley (100 per cent) was 55 per cent for rye, 35 per cent for wheat and only 29 per cent for maize. The egg larvae do not bore immediately into the nearest kernel but are capable of vertical and horizontal migrations. They can actively penetrate into the stored grain from above to a depth of 30 cm and populate chiefly the zone between the depths of 2 cm and 6 cm. They migrate horizontally for distance, up to 25 cm, with differences depending on the light conditions. Other subjects of these studies are problems of infraspecific competition in the density of population and of temperatures increased by metabolic processes. Shortly after emerging, the moths show negative geotaxis and negative thigmotaxis; after copulation there is a general reversal of this behaviour.