title: Action Thresholds for Managing Megacopta cribraria (Hemiptera: Plataspidae) in Soybean Based on Sweep-Net Sampling.
abstract: The kudzu bug, Megacopta cribraria (F.), first discovered in the United States in 2009, has rapidly become a pest of commercial soybean, Glycine max (L.) Merrill, throughout much of the southeast. Because of its recent arrival, management practices and recommendations are not well established. To develop action thresholds, we evaluated insecticide applications targeted at different densities of adults and nymphs determined using the standard 38-cm diameter sweep net sampling method in 12 soybean field trials conducted in Georgia, North Carolina, and South Carolina from 2011 to 2013. Average peak densities of M. cribraria in the untreated controls reached as high as 63.5 ± 11.0 adults per sweep and 34.7 ± 8.0 nymphs per sweep. Insecticide applications triggered at densities of one adult or nymph of M. cribraria per sweep, two adults or nymphs per sweep, and one adult or nymph per sweep, with nymphs present, resulted in no yield reductions in most cases compared with plots that were aggressively protected with multiple insecticide applications. A single insecticide application timed at the R3 or R4 soybean growth stages also resulted in yields that were equivalent to the aggressively protected plots. Typically, treatments (excluding the untreated control) that resulted in fewer applications were more cost-effective. These results suggest that a single insecticide application targeting nymphs was sufficient to prevent soybean yield reduction at the densities of M. cribraria that we observed.
authors.affiliation: Department of Agricultural and Environmental Sciences, Clemson University, Edisto Research and Education Center, 64 Research Rd., Blackville, SC 29817. Present address: Division of Agriculture, University of Arkansas, Southeast Research and Extension Center, P.O. Box 3508, Monticello, AR 71656. nseiter@uaex.edu.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Seiter
authors.affiliation: Department of Entomology, North Carolina State University, 100 Derieux Pl., 2301 Gardner Hall, Raleigh, NC 27695.
authors.forename: Alejandro I
authors.initials: AI
authors.lastname: Del Pozo-Valdivia
authors.affiliation: Department of Agricultural and Environmental Sciences, Clemson University, Edisto Research and Education Center, 64 Research Rd., Blackville, SC 29817.
authors.forename: Jeremy K
authors.initials: JK
authors.lastname: Greene
authors.affiliation: Department of Agricultural and Environmental Sciences, Clemson University, Pee Dee Research and Education Center, 2200 Pocket Rd., Florence, SC 29506.
authors.forename: Francis P F
authors.initials: FP
authors.lastname: Reay-Jones
authors.affiliation: Department of Entomology, University of Georgia, Tifton Campus, 2360 Rainwater Rd., Tifton, GA 31793.
authors.forename: Phillip M
authors.initials: PM
authors.lastname: Roberts
authors.affiliation: Department of Entomology, North Carolina State University, 207 Research Station Rd, Plymouth, NC, 27962.
authors.forename: Dominic R
authors.initials: DR
authors.lastname: Reisig
mesh_terms: D000818:Animals; D005845:Georgia; D020062:Heteroptera; D007300:Insect Control / Q000379:methods*; D007306:Insecticides; D009657:North Carolina; D009758:Nymph; D011156:Population Density; D013022:South Carolina; D013025:Glycine max / Q000254:growth & development
chemical_list: D007306:Insecticides
keywords: cumulative insect day; economic benefit; invasive species; yield component