Food stealing in cockroaches

Abstract

Relationships between food stealing and exploitation of main food sources were investigated in the German cockroach,Blattella germanica (L.) (Dictyoptera: Blattellidae). The occurrence of food stealing during food exploitation was associated with the course of depletion of the main food sources and not with spatial distribution or distance from shelter. Stolen pieces of food always appeared towards the end of exploitation of a food source. Their occurrence appeared to be a consequence of the exploitation of a food source rather than a specific strategy. The proportion of animals of different developmental stages observed with stolen pieces differed significantly from that in the general population. There were proportionally more males, females and large larvae and proportionally less small larvae with stolen pieces than on the main food source. These data suggest that stolen pieces appeared when competition for access to food increased, and that larger cockroaches (adults and larger larvae) were then dominant and benefited from monopolizing stolen pieces of food.