Central Science Laboratory, Sand Hutton, York, YO41 1LZ, UK.
To avoid contamination and damage to commodities early detection of insect pests is an essential part of integrated pest management strategies. Traps are more effective than sampling methods for the detection and monitoring of insect pests but detect only a small proportion of the insects present. Trap performance can be enhanced by incorporation of a lure, based on pheromones or food attractants. Male stored product beetles in the genera Oryzaephilus and Cryptolestes produce aggregation pheromones. These are a blend of two or more macrolide lactones and some will attract more than one species. These pheromones are therefore good candidates as components of a multi-species lure. A multi-species lure is desirable as a range of species may be present and it is impractical to use different lures. O. surinamensis, the commonest insect pest in UK stored grain, produces lactones II, III and IV which elicit electroantennogram (EAG) and behavioural responses from males and females. In this investigation the EAG technique was used to determine whether the other four macrolide lactones would elicit an EAG response in this species. Three log concentrations of each of the seven lactones were tested. A solution of carob volatiles was used as the standard. At the concentrations tested only lactones III and IV gave significant EAG responses. The perception threshold was 100 ng for lactone III and 1000 ng for lactone IV. Therefore only these two lactones are candidates for a multi-species lure.