The effect of plant nutritional quality on the foraging decisions of omnivores

Dicyphus hesperus Knight (Hemiptera: Miridae), a generalist omnivore, feeds on both plant and prey resources depending on the availability and profitability of each. This study quantifies the prey feeding that occurs following plant feeding on high quality versus low quality plants. Twenty plants each of pepper and chrysanthemum were divided into two treatment groups: fertilized and non-fertilized. For a period of five weeks time the fertilized groups were treated with 10-52-10 fertilizer once per week whereas the non-fertilized groups were not treated with any form of fertilizer. Three female adult D. hesperus were placed on each plant in an individual 2.0’ x 2.0’ x 2.0’ cage and left without prey for 96 hours. Following this, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs were added to each cage for 48 hours. Prey consumption was measured in each cage to determine if the quality of plant played a role in food selection. It was predicted that D. hesperus feeding on the non-fertilized plants would consume more of the prey then the D. hesperus feeding on the fertilized plants.