The role of omnivory in the conservation of predators: Orius majusculus (Heteroptera: Anthocoridae) on sweet alyssum

In conservation biological control programs, provision of the required resources (shelter, food, oviposition sites) can be achieved by means of the use of insectary plants. This is especially important in the case of omnivorous predators that feed on prey and plant materials, and where the availability of plant resources plays a significant role in their conservation. An important predator of thrips and other pests in the Mediterranean is the omnivorous bug Orius majusculus (Reuter) (Hemiptera: Anthocoridae). The objective of this study was to evaluate the fertility, fecundity and longevity of O. majusculus on alyssum, (Lobularia maritima L.) with and without prey (Ephestia kuehniella eggs), and compare it with green bean pods. Additionally, the effects of the breeding colony of the individuals on the fertility of O. majusculus were studied. Fecundity on both plants without prey was low; however the addition of prey significantly increased the number of eggs laid, especially on alyssum. The longevity differed significantly among diets, being longer for alyssum with prey eggs. Survival on alyssum without prey was not statistically different from green bean with prey, which shows the potential of alyssum to conserve O. majusculus during times of prey scarcity. The fertility of O. majusculus females was significantly higher on the diets of both plant materials when prey was included. Our results showed that alyssum can provide resource subsidies for O. majusculus during times of prey scarcity in the field. (C) 2012 Elsevier Inc. All rights reserved.