Factors affecting the antennal and behavioural responses of the saw‐toothed grain beetle Oryzaephilus surinamensis to food odour and aggregation pheromone

Abstract

ABSTRACT. The effects of insect age, sex, mated state and culture density on the attraction of adult saw‐toothed grain beetles, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), to sources of food odour and synthetic aggregation pheromone were investigated. In single‐insect behavioural assays, insect age affected the attraction to the food odour, but not to the synthetic aggregation pheromone. Conversely, there were sexual differences in the attraction to the aggregation pheromone, but not to the food odour. The effects of the same factors on the antennal response to food odour and synthetic pheromone were also investigated, using the electroantennogram (EAG) technique. Insect age affected the EAG response to food odour, but not to the synthetic pheromone. There were no sexual differences in the EAG responses to either food odour or synthetic pheromone.The correlation of factors affecting both behavioural and antennal responses, and the possible role of changes in peripheral olfactory receptor sensitivity in the modulation of behaviour are discussed.