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ARS Home » Plains Area » Brookings, South Dakota » Integrated Cropping Systems Research » Research » Publications at this Location » Publication #250291
Title: Oviposition Response by Orius Insidiosus (Hemiptera: Anthocoridae) to Plant Quality and Prey Availability

Author
item Seagraves, Michael
item Lundgren, Jonathan

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2010
Publication Date: 10/25/2010
Citation: Seagraves, M.P., Lundgren, J.G. 2010. Oviposition response by Orius insidiosus (Hemiptera: Anthocoridae) to plant quality and prey availability. Biological Control. 55:174-177.

Interpretive Summary: The pirate bug, Orius insidiosus, is an important predator of the invasive soybean aphid and aids in slowing population growth of that pest. Orius insidiosus consumes a mixed diet of prey and plant-based foods through its life. Plant species identity affects the egg laying behavior of O. insidiosus in that it prefers plants where newly hatched nymphs perform best, in the absence of prey. Choice tests were conducted to determine if the presence of a high-quality prey item affects egg laying in a monoculture and also how prey presence affects egg laying preference for plants of high (green bean) or low (soybean) suitability for O. insidiosus. Orius insidiosus laid 56.4% more eggs on prey-free green bean than prey-free soybean. The presence of prey on green bean increased oviposition on those plants by 26.4% over that laid on prey-free green bean. When soybean with prey was presented alongside prey-free green bean, O. insidiosus still laid 55.4% more eggs on the latter. Prey availability affects oviposition on plants of equivalent quality, but plant suitability over-rides the importance of prey availability for this omnivorous beneficial insect. Plant feeding in young nymphs is important for their survival and we hypothesize that O. insidiosus females are better able to forecast plant quality than future prey populations as resources for their offspring. It appears that the inclusion of plant diversity in cropping systems will favor this natural enemy. Knowledge of how this natural enemy makes egg-laying decisions will inform the design of cropping systems with more biological control of the soybean aphid.

Technical Abstract: The predator Orius insidiosus consumes a mixed diet of prey, vascular sap, and plant-based foods through its life. Plant species identity affects the oviposition behavior of O. insidiosus in that it prefers plants where newly hatched nymphs perform best, in the absence of prey. Choice tests were conducted to determine if the presence of a high-quality prey item affects oviposition choice in a monoculture and also how prey presence affects oviposition preference for plants of high (i.e., Phaseolus vulgaris) or low (Glycines max) suitability for O. insidiosus. Orius insidiosus laid 56.4% more eggs on prey-free P. vulgaris than prey-free G. max. The presence of prey on P. vulgaris increased oviposition on those plants by 26.4% over that laid on prey-free P. vulgaris. When G. max with prey was presented alongside prey-free P. vulgaris, O. insidiosus still laid 55.4% more eggs on the latter. Prey availability affects oviposition on plants of equivalent quality, but plant suitability over-rides the importance of prey availability for this zoophytophagous insect. Phytophagy in young nymphs is important for their survival and we hypothesize that O. insidiosus females are better able to forecast plant quality than future prey populations as resources for their offspring.