title: Emergence, Seasonality, and Hybridization of Laricobius nigrinus (Coleoptera: Derodontidae), an Introduced Predator of Hemlock Woolly Adelgid (Hemiptera: Adelgidae), in the Tennessee Appalachians.
abstract: From 2010 through 2013, adult emergence and seasonality of Laricobius nigrinus Fender, an introduced predatory species native to western North America, as well as hybridization with the native species Laricobius rubidus (LeConte), were evaluated using emergence traps and beat-sheet sampling in areas of previous release against hemlock woolly adelgid, Adelges tsugae Annand. The shortest emergence period of adult L. nigrinus was 7 wk beginning 22 October 2010, and the longest emergence was 15 wk beginning 17 October 2012. Native L. rubidus also were collected from emergence traps placed on the ground surface and beat-sheet samples all 3 yr, with emergence of L. rubidus initiating later than L. nigrinus each season. Seasonality of both Laricobius species was similar across a 44-mo study period. Adult L. nigrinus were present from October through April, and larvae of Laricobius spp. were collected from February to May. The average number of L. nigrinus from emergence traps was significantly greater than the average number of beetles collected from beat-sheet samples in 2010, while the converse was observed during 2012. Hybridization between L. nigrinus and L. rubidus was documented from 10.75% of specimens collected during 2010 and 2011, indicating periodic interbreeding between the introduced and native species. These findings suggest emergence trapping may be a useful method to assess establishment, population densities, and seasonality of Laricobius species in areas of release to enhance their use in management of A. tsuage.
authors.affiliation: Department of Entomology and Plant Pathology, University of Tennessee, 370 Plant Biotechnology Bldg., 2505 E.J. Chapman Dr., Knoxville, TN 37996 (wiggybug@utk.edu; jgrant@utk.edu; plambdin@utk.edu) wiggybug@utk.edu.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Wiggins
authors.affiliation: Department of Entomology and Plant Pathology, University of Tennessee, 370 Plant Biotechnology Bldg., 2505 E.J. Chapman Dr., Knoxville, TN 37996 (wiggybug@utk.edu; jgrant@utk.edu; plambdin@utk.edu).
authors.forename: Jerome F
authors.initials: JF
authors.lastname: Grant
authors.affiliation: U.S.D.A. Forest Service, Forest Health Protection, 200 W.T. Weaver Blvd., Asheville, NC 28804 (rrhea@fs.fed.us).
authors.forename: James R
authors.initials: JR
authors.lastname: Rhea
authors.affiliation: U.S.D.A. Forest Service, Southern Research Station, 200 W.T. Weaver Blvd., Asheville, NC 28804 (amayfield02@fs.fed.us).
authors.forename: Albert E
authors.initials: AE
authors.lastname: Mayfield
authors.affiliation: Texas A&M AgriLife Research and Extension Center, 1102 East FM 1294, Lubbock, TX 79403 (abdul.hakeem@ag.tamu.edu).
authors.forename: Abdul
authors.initials: A
authors.lastname: Hakeem
authors.affiliation: Department of Entomology and Plant Pathology, University of Tennessee, 370 Plant Biotechnology Bldg., 2505 E.J. Chapman Dr., Knoxville, TN 37996 (wiggybug@utk.edu; jgrant@utk.edu; plambdin@utk.edu).
authors.forename: Paris L
authors.initials: PL
authors.lastname: Lambdin
authors.affiliation: Roane State Community College, 701 Briarcliff Ave., Oak Ridge, TN 37830 (gallowayab@roanestate.edu).
authors.forename: A B Lamb
authors.initials: AB
authors.lastname: Galloway
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D020387:Food Chain; D006430:Hemiptera / Q000502:physiology; D006824:Hybridization, Genetic; D007814:Larva / Q000254:growth & development / Q000502:physiology; D011157:Population Dynamics; D011679:Pupa / Q000254:growth & development / Q000502:physiology; D012621:Seasons; D013714:Tennessee
keywords: Adelges tsugae; Laricobius nigrinus; Laricobius rubidus; biological control; hemlock woolly adelgid