Predation on stink bugs (Hemiptera: Pentatomidae) in cotton and soybean agroecosystems

Authors: ATHEY, KACIE - University Of Kentucky; RUBERSON, JOHN - Kansas State University; Olson, Dawn; HARWOOD, JAMES - University Of Kentucky

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2019
Publication Date: 3/27/2019
Citation: Athey, K., Ruberson, J., Olson, D.M., Harwood, J. 2019. Predation on stink bugs (Hemiptera: Pentatomidae) in cotton and soybean agroecosystems. PLoS One. 14(3):e0214325. https://doi.org/10.1371/journal.pone.0214325.
DOI: https://doi.org/10.1371/journal.pone.0214325

Interpretive Summary: Integrated pest management (IPM) programs can benefit greatly from incorporating biological control and reducing chemical control. Insect and spider predators contribute vital ecosystem services through pest control, and pest control utilizing these species in the United States has been estimated to save $4.5 billion annually. Stink bugs (Hemiptera: Pentatomidae) continue to be significant economic pests of cotton and soybeans in the southeastern United States. Three of the most prominent stink bug pests are Nezara viridula, Euschistus servus and Chinavia hilaris. Several studies have identified a complex of predators of stink bugs through enzyme-linked immunosorbent assays, direct observations and placement of stink bug egg baits where their combined predation at times were high. Most of these studies were conducted on N. viridula, and the percentage that each predator species contributed to the complex was variable over crop, season and year. With the advent of polymerase chain reaction (PCR) techniques for identifying predator gut-content positives for different prey it may be possible to increase our knowledge of the trophic interactions of predators. Only one recent study has utilized PCR for identifying stink bug predators, but the study was conducted at a single site and year, only at field edges and only over 5 weeks. With PCR, it may be possible to understand trophic interactions of predators more fully on a wider range of stink bug species and over larger spatial and temporal scales which may be needed to unearth the underlying mechanisms of stink bug predation and ultimately the efficacy of biological control of stink bugs.

Technical Abstract: Stink bugs (Hemiptera: Pentatomidae) are significant pests of cotton and soybeans in the southeastern United States with annual control costs exceeding $14 million. Three of the most prominent stink bug pests are Nezara viridula, Euschistus servus and Chinavia hilaris. To determine trophic linkages between generalist arthropod predators and these pests, species-specific 16S molecular markers were designed and used to detect the presence of prey DNA in predator gut-contents. Over 2700 predators were collected over two growing seasons in cotton and soybean in southern Georgia in 2011 and 2012 and screened for stink bug DNA. Trophic linkages were analyzed relative to prey availability, crop type and field location. Gut-content positives were negligible on E. servus (0.23%) and C. hilaris (0.09%). Overall gut-content positives for N. viridula was 3.3% and Geocoris sp. (Hemiptera: Geocoridae), Orius sp. (Hemiptera: Anthocoridae) and Notoxus monodon (Coleoptera: Anthicidae) were the primary predators. This contrasts with a previous study that reported a much more diverse suite of predators consuming stink bugs with much higher frequency of gut-content positives. The discrepancy between studies highlights the need for replicating studies in space and time, and broader assessments of cross-reactivity and primer design especially if the goal is to implement effective and durable conservation biological control in integrated pest management.