Effect of diet on the reproductive biology of the omnivorous biological control agent Orius laevigatus

Orius laevigatus is an effective biological control agent of agricultural pests such as mites and thrips. The ability of Orius to feed on both prey and plant materials may alter its behavior, reproduction and performance. These in turn would affect its ability to build up populations and suppress pest infestations. To test the nutritional effect of diets on Orius reproduction, we compared O. laevigatus reproductive biology when fed pollen (Typha dominguesis) or flour moth eggs (Ephestia kuehniella Zeller). Results to date indicate that body size of both females and males was affected by diet; individuals fed on pollen were smaller by about 7 % compare to those fed on prey. Yet male body size did no influence mate selection by the females. Copulation duration was longer for pairs fed on the same diet compare to those feeding on different food sources. Females laid about 50% more eggs when they chose males that fed the same diet, whether it was prey or pollen (120 and 93 eggs/female, respectively), compared to female that mated to males fed a different diet. Taken together, results suggest that when prey is scares in the field and both sexes feed on pollen, reproduction may be sustained and O. laevigatus populations persist until pests reappear in the field. This natural enemy may then be able to rapidly suppress pest populations preventing it from reaching economically-damaging levels.