IMPORTANCE of SPATIAL and OLFACTORY LEARNING on BAIT CONSUMPTION in the GERMAN COCKROACH

Abstract:
The objective of the research presented here was to evaluate the impact of the introduction of a toxic food bait on foraging choice by the German cockroach, Blattella germanica (L.). This was done by analysing the importance of learning visual cues associated with feeding sites and the importance of feeding experience. Cockroaches were able to associate visual cues with food and to use these learned cues to forage. A new food type placed in a new site attracted more cockroaches than the known food type in the known site. When the known food type was in a new site and the new food type in the known feeding site, most of the cockroaches oriented towards the known food type and neglected the new one. These results revealed that many factors influence the discovery and ingestion of a food source and that cockroaches take different foraging decisions in relation to the current environmental situation. They are able to distinguish a novel food placed in a novel site from a novel food placed in a site previously occupied by another food type. This also means that cockroaches learn the location of specific food resources and associate particular locations with particular resources. The results show the role of environmental parameters of feeding decisions in cockroaches. This complexity must be taken into account to optimize insecticide treatments with food baits.