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    Author(s): Gregory J. Wiggins; Jerome F. Grant; Rusty RheaAlbert (Bud) Mayfield; Abdul Hakeem; Paris L. Lambdin; A. B. Lamb Galloway
    Date: 2016
    Source: Environmental Entomology
    Publication Series: Scientific Journal (JRNL)
    Station: Southern Research Station
    PDF: Download Publication  (589.0 KB)


    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.

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    Wiggins, Gregory J.; Grant, Jerome F.; Rhea, James R.; Mayfield, Albert E.; Hakeem, Abdul; Lambdin, Paris L.; Galloway, A. B. Lamb. 2016. Emergence, seasonality, and hybridization of Laricobius nigrinus (Coleoptera: Derodontidae), an introduced predator of hemlock woolly adelgid (Hemiptera: Adelgidae), in the Tennessee Appalachians . Environmental Entomology, Vol. 45(6): 8 pages.: 1371-1378. doi: 10.1093/ee/nvw128


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    Laricobius nigrinus, Laricobius rubidus, hemlock woolly adelgid, Adelges tsugae, biological control

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