Location: Integrated Cropping Systems ResearchTitle: Diversity of floral and extrafloral nutritional resources on the fitness of an omnivorous bug, Orius insidiosus (Hemiptera: Anthocoridae)) Author
Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2012
Publication Date: 9/14/2012
Citation: Pumarino, L., Alomar, O., Lundgren, J.G. 2012. Diversity of floral and extrafloral nutritional resources on the fitness of an omnivorous bug, Orius insidiosus (Hemiptera: Anthocoridae). Entomologia Experimentalis et Applicata. 145:181-190. Interpretive Summary: The minute pirate bug, Orius insidiosus, is a beneficial insect in that it consumes crop pests throughout eastern North America. But in addition to consuming pests, this bug also eats plant tissue (with little or no damage to the plants). Efforts are underway to conserve this predator within cropland using non-crop plants, especially those with flowers and extrafloral nectaries (plant sap). The current work determined how various plant species (alyssum, buckwheat, phacelia, chamomile, and faba bean) affected the survival, egg production, longevity, and ability of the bugs to store glycogen and lipids. Moreover, we evaluated whether floral and extrafloral resources (nectar and pollen) of these plants improved these life history characteristics of the predator. Bugs performed very differently on the various plants, and availability of flowers improved Orius survival and egg production. Interestingly, faba beans (which had extrafloral nectar, but not flowers) had few eggs laid on them when the plant was offered under no-choice conditions. However, when plants were offered as a mixture, faba beans were the preferred plant for receiving eggs. This research points out that predicting which plants have the most conservation benefits is context specific, and makes the case for conserving plant diversity as a whole in biological control programs.
Technical Abstract: Habitat manipulation and increasing biodiversity are important tools for enhancing biological control of pests but it is important to evaluate the relative benefits of specific plant species when designing conservation plans. Orius insidiosus is an important predator of thrips and aphids that also feeds on plants. It is the target of conservation biological control programs. Despite its relevance, little is known about the effects of plant subsidies on predator performance or nutritional status. Here we examined the influence of five plant species (alyssum, buckwheat, phacelia, faba bean and chamomile), the effects of restricting their pollen and nectar resources, and how increasing plant diversity affects O. insidiosus fecundity, survival and nutritional status. Plant species varied in their suitability for O. insidiosus, which was driven in part by the availability of the pollen or nectar sources. Offering plants as a mixture did not improve fecundity, however the plant least preferred for oviposition under no-choice tests (faba bean) became the preferred egg-laying site when the plants were offered in combination. We conclude that the benefits obtained by O. insidiosus varies among plant species, and that increasing plant diversity can have unpredicted, positive effects on insect fitness.