Influence of Plant Physical and Anatomical Characteristics on the Ovipositional Preference of Orius sauteri (Hemiptera: Anthocoridae)

SIMPLE SUMMARY: The minute pirate bug Orius sauteri is the predator of many soft-body pests and has great application prospect in pest suppression in Asia. Females need to insert their ovipositor into plant tissues to lay eggs. Thus, understanding its egg-laying preferences and creating it a beneficial habitat is important for its conversation in the field. We evaluated the ovipositional preference of the females for four noncrop plant species and how the plant characteristics influenced the ovipositional behavior of O. sauteri. Our results suggested that O. sauteri females were able to select oviposition host and specific sites through assessing the structural qualities of plants. Females were found to prefer plants with high stomatal density, a large stomatal area, and fewer trichomes as oviposition hosts, and the depth of egg placement was determined by leaf thickness. Coriander and marigold are potential oviposition plants for O. sauteri for high fecundity and egg hatchability. The results are helpful for selecting beneficial cover crops to natural enemies in the field and lead to a positive outcome for biological control. ABSTRACT: Natural enemies play an important role in managing insect pests. Orius sauteri (Poppius) (Hemiptera: Anthocoridae), a predator of many soft-body insects, is an important biological control agent in Asia. Understanding this predator’s egg-laying preferences and a habitat needs is important for its success in pest control. We investigated the plant acceptability and ovipositional preference of O. sauteri for coriander (Coriadrum sativum L., Apiales: Apiaceae), marigold (Tagetes erecta L., Asterales: Asteraceae), sweet alyssum (Lobularia maritima L., Brassicales: Brassicaceae), and alfalfa (Medicago sativa L., Fabales: Fabaceae), and focused on the effects of plant physical and anatomical characteristics on the ovipositional preference of O. sauteri. The results showed that O. sauteri can lay eggs on uninfested plants in the vegetative stage and their eggs hatched normally. Orius sauteri females prefer plants with high stomatal density, a large stomatal area, and fewer trichomes as oviposition hosts, and the depth of egg placement was determined by leaf thickness. Our studies suggested that O. sauteri females can select oviposition hosts and specific oviposition sites by assessing the structural qualities of plant surface. Coriander and marigold are potentially suitable host plants for O.sauteri. The results aid the selection of cover crops to enhance natural enemies in the fields.