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United States Department of Agriculture

Agricultural Research Service

Title: Quantitative Evaluation of the Impact of Entomophaga Maimaiga on Selected Gypsy Moth Populations in Four Mid-Atlantic States 1997

Authors
item Webb, Ralph
item White, Geoffrey

Submitted to: National Gypsy Moth Review Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 3, 1997
Publication Date: N/A

Technical Abstract: Gypsy moth populations and associated natural enemies were characterized at selected mid-Atlantic locations by a series of samplings: egg mass, and early-season, mid-season, and late-season larval collections. Specifically, 4-5 collections were made in plots near Vineland, NJ (4 sites), Cameron, WV (3 sites), Ocean City, MD (2 sites), and Northern Virginia (2 sites). The first collection consisted of 100 larvae from each plot sampled just after egg hatch. Later collections were made 2 weeks apart. All larvae were placed individually in 30 cc diet cups, taken to Beltsville, and held in an outdoor insectary and were checked weekly for mortality for five weeks. The source of mortality was determined for each cadaver by light microscopy. Our general findings were: 1) E. maimaiga was present at (almost) all locations, but with varying impacts; 2) LdNPV was present at (almost) all locations, but with varying impacts; 3) Ooencyrtis was prominent at all locations, but other parasitoids were present only at very low levels; 4) E. maimaiga appeared to be coexisting with LdNPV, but plots with higher levels of fungus generally had less virus, especially late in the season; 5) in all four areas in 1997, there were sufficient early-season larvae to keep the virus in the game, while significant late season fungal mortality thinned late-instar larval numbers, which worked against a second-wave LdNPV-induced gypsy moth population collapse, but did not eliminate the virus.

Last Modified: 8/30/2014
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