Submitted to: Biocontrol
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 13, 2005
Publication Date: May 1, 2006
Citation: Lundgren, J.G., Fergen, J.K. 2006. The oviposition behavior of the predator, orius insidiosus: acceptability and preference for different plants. BioControl (2006) 51: 217-227. Interpretive Summary: Orius insidiosus is an important predator of soybean aphid, the dominant pest of soybeans in the United States. The ability of O. insidiosus to quickly respond to aphid outbreaks is dependent on the predator’s ability to reproduce within soybeans. Orius insidiosus lays its eggs beneath the epidermis of plants, and we evaluated the acceptability and preference for different agriculturally relevant plants as oviposition sites. We found that O. insidiosus has distinctive preferences for certain plants. They do not prefer to lay eggs on soybean plants when given a choice between pole beans, redroot pigweed, and soybean. This has important implications for the population dynamics of the predator within soybean fields and the biological control of soybean aphid.
Technical Abstract: The ability of natural enemies to reproduce within cropland and effectively suppress pests depends on the presence of plants on which to oviposit within the agroecosystems. Our research investigates the acceptability and preferences of a range of plants for oviposition by the predatory bug Orius insidiosus (Say) (Hemiptera: Anthocoridae). Within-plant preferences on pole beans as oviposition sites were evaluated in laboratory choice tests. The acceptability and preference of O. insidiosus females for pole bean, soybean, redroot pigweed, and velvetleaf were evaluated in choice and no-choice tests (respectively) in the laboratory. Observations on the acceptability of green foxtail, orchardgrass, buffalograss, smooth brome, redtop grass, blue grama, and tall fescue for oviposition were also conducted. O. insidiosus preferred to lay its eggs on the petiole and leaflet petioles of pole beans, and did not distinguish among nodes or petioles of different lengths. Although all broadleaved plants were suitable for egg development, the acceptability of these plants differed significantly, with pole beans being most acceptable and almost no eggs being laid on velvetleaf. Preference tests supported the results of the no-choice tests, with pole bean being the most preferred, and no eggs being laid on the velvetleaf. Green foxtail and orchardgrass were the only grass species found to be acceptable to O. insidiosus. The implications of soybean monocultures on the reproductive capacity of and biological control by O. insidiosus are discussed, as are possible mechanisms underlying the decision-making process for oviposition.