title: Cereal Leaf Beetle (Coleoptera: Chrysomelidae) Regional Dispersion and Relationship With Wheat Stand Denseness.
abstract: Cereal leaf beetle, Oulema melanopus L., is a pest of small grains and the literature conflicts on whether it is more abundant in sparse or dense stands of wheat. Our objectives were to determine the impact of stand denseness on cereal leaf beetle abundance and to investigate the regional dispersion of cereal leaf beetles across North Carolina and Virginia. One-hundred twenty fields were sampled across North Carolina and Virginia during 2011 for stand denseness, and cereal leaf beetle eggs, larvae, and adults. Two small-plot wheat experiments were planted in North Carolina using a low and a high seeding rate. Main plots were split, with one receiving a single nitrogen application and one receiving two. Egg density, but not larva or adult density, was positively correlated with stand denseness in the regional survey. Furthermore, regional spatial patterns of aggregation were noted for both stand denseness and egg number. In the small-plot experiments, seeding rate influenced stand denseness, but not nitrogen application. In one experiment, egg densities per unit area were higher in denser wheat, while in the other experiment, egg densities per tiller were lower in denser wheat. Larvae were not influenced by any factor. Overall, there were more cereal leaf beetle eggs in denser wheat stands. Previous observations that sparse stands of wheat are more prone to cereal leaf beetle infestation can be attributed to the fact that sparser stands have fewer tillers, which increases the cereal leaf beetle to tiller ratio compared with denser stands.
authors.affiliation: Department of Entomology, North Carolina State University, Vernon G. James Research and Extension Center, 207 Research Station Rd., Plymouth, NC, 27962 (ddreisig@ncsu.edu).
authors.forename: Dominic D
authors.initials: DD
authors.lastname: Reisig
authors.affiliation: Department of Entomology, North Carolina State University Raleigh, NC 27695 (jsbachel@ncsu.edu).
authors.forename: Jack S
authors.initials: JS
authors.lastname: Bacheler
authors.affiliation: Department of Entomology, Virginia Polytechnic Institute and State University (herbert@vt.edu; tkuhar@vt.edu; smalone@vt.edu).
authors.forename: D Ames
authors.initials: DA
authors.lastname: Herbert
authors.affiliation: Department of Crop Science, North Carolina State University (rheinig@ncsu.edu)Plymouth, NC 27962.
authors.forename: Ron
authors.initials: R
authors.lastname: Heiniger
authors.affiliation: Department of Entomology, Virginia Polytechnic Institute and State University (herbert@vt.edu; tkuhar@vt.edu; smalone@vt.edu).
authors.forename: Thomas
authors.initials: T
authors.lastname: Kuhar
authors.affiliation: Department of Entomology, Virginia Polytechnic Institute and State University (herbert@vt.edu; tkuhar@vt.edu; smalone@vt.edu).
authors.forename: Sean
authors.initials: S
authors.lastname: Malone
authors.affiliation: Department of Entomology, University of Minnesota Grand Rapids, MN 55744 (cphilips@umn.edu).
authors.forename: Chris
authors.initials: C
authors.lastname: Philips
authors.affiliation: North Carolina State University Cooperative Extension Plymouth, NC 27962 (mstilley@ncsu.edu).
authors.forename: M Scott
authors.initials: MS
authors.lastname: Tilley
mesh_terms: D000383:Agriculture / Q000379:methods*; D063147:Animal Distribution; D000818:Animals; D001517:Coleoptera / Q000254:growth & development / Q000502:physiology*; D007814:Larva / Q000502:physiology; D009657:North Carolina; D011156:Population Density; D014908:Triticum / Q000254:growth & development*; D014768:Virginia
keywords: Moran’s I; oviposition; sampling; spatial distribution