Conoideocrella luteorostrata, a Potential Biocontrol of Elongate Hemlock Scale in the Eastern United States

Hosanna Barrett*, Brian Lovett, and Matt T. Kasson

Presentation No.: 1

Assigned Category (Presentation Format): Agricultural & Environmental Sciences (Oral Presentations)

Student’s Major: Biology

The goal of this project is to develop natural fungal pathogens of the invasive Christmas tree pest elongate hemlock scale insects in the eastern U.S. as biocontrol agents. In the Summer of 2020, a fungus causing an epizootic in elongate hemlock scales in North Carolina was isolated and molecularly identified as Conoideocrella luteorostrata (Clavicipitaceae, Hypocreales, Ascomycota). Elongate hemlock scales in the nymph and adult female stages on hemlock branches were dipped in C. luteorostrata spores suspended in a 0.01% Tween20 solution at various concentrations. Observed symptoms and mortality in the treatments were reported daily for two weeks and maintained to observe any additional symptoms. Several of these treatments were conducted to optimize our protocol. Fungal outgrowth was not observed in the adult females in this setting, but C. luteorostrata was re-isolated from a treated nymph. We intend to further investigate the pathogenicity of this fungus through bioassays against elongate hemlock scale crawlers. C. luteorostrata may provide a biocontrol option for Christmas tree farmers.

Funding: Christmas tree promotion board Grant #20-10-WVU

Program/mechanism supporting research/creative efforts: WVU's SURE program (Rita Rio & Michelle Richards-Babb)