Pheromone Output by <I>Rhyzopertha dominica</I> (Coleoptera: Bostrichidae), as Affected by Host Plant and Beetle Size

Abstract

Abstract Males of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), the lesser grain borer, produce the aggregation pheromones dominicalure-1 (DL-1) and dominicalure-2 (DL-2), which attract conspecifics for mating and to food sources. Pheromone emissions by single males feeding on 10 different plant-based diets were analyzed in a laboratory study by gas chromatography to compare effects of different host plants on pheromone emission. Body size measurements also were made from individual male R. dominica feeding on a single host to investigate variation in pheromone output and to determine the relationship, if any, between body size and pheromone output in the species. Hosts on which larvae were reared did not affect pheromone output, but hosts on which adult males fed had significant effects. Mean total pheromones (DL-1+DL-2) released by male R. dominica confined on wheat seeds for 24 h was 1,060 ng at 20 d old. There was a significant reduction in mean total pheromones (DL-1+DL-2) output from 1,246 n...