Effects of Plants and Supplemental Prey on Establishment of Dicyphus hesperus (Hemiptera: Miridae)

Abstract

Dicyphus hesperus Knight (Hemiptera: Miridae) is an omnivorous natural enemy used to control insect pests in greenhouse structures. The establishment and population development of predators in a banker plant system must be understood prior to their deployment in a pest management program. Banker plants are non-crop plants that are infested with a supplemental food source, which provides a suitable environment for predators to establish their population. The objective of this research was to investigate the effect of mullein (Verbascum thapsus L.; Scrophulariaceae) as banker plants and Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs as supplemental food on the development of D. hesperus in a tomato greenhouse production system. The nymphal development duration did not differ between mullein (22.5 d) and tomato (24.5 d) with E. kuehniella eggs but was significantly longer on mullein (25.8 d) without E. kuehniella eggs, whereas nymphs did not complete their life cycle on tomato without E. kuehniella eggs. Adult longevity and percentage survival to adulthood was 30.4 d and 91.9% on mullein with E. kuehniella eggs, and 26.9 d and 87.5% on tomato with E. kuehniella eggs, but were much reduced on mullein without E. kuehniella eggs (22.44 d and 75%). The population growth of the predator varied in response to host plant and presence of supplemental food source. In greenhouse experiments, the population of D. hesperus showed a greater increase on tomato provided with E. kuehniella eggs as a supplement food source than on mullein with supplemental food. We conclude that there was no benefit in our experiments to using mullein as a banker plant rather than using the commercial crop, tomato, supplemented with E. kuehniella eggs.