Population responses by Orius insidiosus to vegetational diversity

Abstract

The abundance of different life stages of Orius insidiosus (Say) (Heteroptera: Anthocoridae) and its prey were recorded in vegetationally diverse (soybean and agronomic weeds) and monoculture (soybean only) fields. Orius insidiosus adults and nymphs were more abundant in diversified plots than in monocultures. A similar number of O. insidiosus eggs were found in the two treatments, but twice as many eggs were laid on non-crop plants than on soybeans within the vegetationally diverse plots. Prey densities were equivalent in the two treatments. In olfactometer assays, naïve O. insidiosus females were unresponsive to odors from three weed species (morning glory, redroot pigweed and velvetleaf). The current results, coupled with previous experimental observations, lead us to believe that higher abundance of O. insidiosus in vegetationally diverse habitats could be related to improved fitness of the predator, which in turn is related to certain plant qualities (e.g., nutrition, plant architecture, etc.). Proximal cues are likely more influential to oviposition decisions by O. insidiosus females than volatile signals.

Insect communities in soybeans of eastern South Dakota: The effects of vegetation management and pesticides on soybean aphids, bean leaf beetles, and their natural enemies

“…O. insidiosus is an important predator of soybean thrips and the soybean aphid (Brosius et al, 2007;Butler and O'Neil, 2008;Desneux and O'Neil, 2008;Harwood et al, 2009). This omnivorous bug also has strong preferences for specific plant species as oviposition sites, and increased vegetation diversity has been shown to increase O. insidiosus populations (Lundgren et al, , 2009bSeagraves and Lundgren, 2010). Insecticides aimed at aphid management also adversely affect O. insidiosus (Seagraves and Lundgren, 2012).…”

“…Cover crops do not necessarily have these negative effects on soybean yields (Davis, 2010;Smith et al, 2011). Weed populations provide another source of vegetation diversity that is used by natural enemies of soybean aphids (Griffen and Yeargan, 2002;Lundgren et al, 2009b). The effects of weed presence on soybean aphids has not been well studied, but is likely going to be more important as glyphosate-resistant populations of weeds expand their ranges (Lundgren et al, 2009a;Heap, 2012;Mortensen et al, 2012).…”

Ecological compatibility of GM crops and biological control

“…Application of herbicides disrupts entire communities of plants and the insects that live on them, and it takes a substantial amount of time for these communities to recover their normal compositions (Speight and Lawton, 1976;Prasse, 1985;Franz et al, 1997;Landis and Menalled, 1998;Kromp, 1999;Bianchi et al, 2006;Lundgren et al, 2009). In one study, carabid beetles avoided glyphosate-treated cropland for 28 days after the herbicide was applied, presumably because of the reduction of vegetational diversity in treated plots (Brust, 1990).…”

Temperature-dependent functional response of Nesidiocoris tenuis (Hemiptera: Miridae) to different densities of pupae of cotton whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)

“…Including effi cient biological control agents in pest management programs, not only provides more stable control (Lundgren et al, 2009;Aggarwal et al, 2016;Konecka et al, 2016), but compared to chemical control has benefi ts, including the pest not becoming resistant (Liang et al, ensured that all the insects tested were similar in terms of their physiological status and voracity.…”