Synergism Between Synthetic Food Odors and the Aggregation Pheromone for Attracting Carpophilus lugubris in the Field (Coleoptera: Nitidulidae)

Abstract

Natural and synthetic food odors presented alone and in combination with aggregation pheromone were investigated for Carpophilus lugubris Murray in the field. Whole-wheat bread dough and a synthetic bread dough odor were comparable for attracting C. lugubris, a result that paralleled our previous findings in the wind tunnel. The aggregation pheromone alone elicited little beetle response. However, the addition of aggregation pheromone to bread dough or to the synthetic bread dough odor significantly increased beetle attraction to a level 4.8- and 3.1-fold greater, respectively. The seven components in the synthetic bread dough odor were clustered into three groups based on their activities in attracting C. lugubris, and beetle catch was reduced by the elimination of any group. Beetle catch with a three-component blend of acetaldehyde, ethyl acetate, and 2-methylpropanol was also significantly less than that with the seven-component blend. Addition of the aggregation pheromone synergistically increased beetle attraction to synthetic food odor blends by 2.6 to 3.5 times. Synergism did not significantly vary among synthetic food odor blends. This study confirms the chemical identity of food volatiles modulating food finding in C. lugubris, and demonstrates that the wind-tunnel bioassay can act as a good predictor of chemically mediated host finding in the field.