Diversified floral provisioning enhances performance of the generalist predator, Orius insidiosus (Hemiptera: Anthocoridae)

Providing nectar and pollen through the establishment of insectary plants is one approach to conserving natural enemies and enhancing biological control of arthropod pests. Recent studies show that natural enemy performance may be influenced by the diversity of insectary plant species and the resources they provide. We conducted laboratory assays to investigate the influence of buckwheat (Fagopyrum esculentum Moench.) and cowpea (Vigna unguiculata (L.) Walp.) alone and in a mixture on the performance of the insidious flower bug, Orius insidiosus (Say, 1832). We measured performance as longevity, fecundity and predation of O. insidiosus reared on a laboratory diet of Ephestia kuehniella or its field prey, Ostrinia nubilalis (Hübner). O. insidiosus survived on average 20–25% longer and oviposited 67–88% more eggs when provided with either insectary species compared to a water only control. However, when provided with a biculture of cowpea and buckwheat, O. insidiosus survived 35% longer and laid 111% more eggs compared to the water only control, with a strong preference for cowpea as an oviposition host. This study provides novel empirical evidence that cowpea, a plant anecdotally cited for its insectary properties, functions as a preferred oviposition sites compared to buckwheat and laboratory standard green beans. The presence of insectary resources, however, did not significantly influence predation on O. nubilalis sentinel prey by O. insidiosus as we anticipated. These results indicate that the performance of beneficial insects like O. insidious may be differentially influenced by the resources provided by insectary species and should be screened for potential benefits before establishing in field settings. Further implications of plant diversification for conservation biological control are discussed.