Date Approved

12-22-2021

Graduate Degree Type

Thesis

Degree Name

Biology (M.S.)

Degree Program

Biology

First Advisor

Charlyn Partridge

Second Advisor

James M. McNair

Third Advisor

Alexandra Locher

Academic Year

2020/2021

Abstract

Hemlock forests in eastern North America face a deadly threat: the invasive insect, hemlock woolly adelgid (HWA), Adelges tsugae. Early detection of this pest remains a key focus for management groups to ensure rapid response to control and stop the spread of HWA. In Chapter II, our goals were to develop an affordable, easy-to-use trap that is compatible with airborne eDNA sampling techniques and assess its efficiency as a monitoring tool for HWA. We tested three potential trap designs (i.e., passive trap, funnel trap, and motorized trap) against a standard sticky trap. Our passive, funnel, and motorized traps estimated adelgid capture success probabilities compared to sticky traps were 0.87, 0.8, and 0.4, respectively. We then further assessed the motorized trap after modifying the original design. In the secondary study, the motorized trap increased in estimated success probability to 0.67. We also evaluated how many traps would be needed in a set area size to maintain high probability of detecting HWA and measured how environmental variables affected trap performance in capturing adelgids. We found that number of traps placed within a 3-acre area did not impact trap capture success over a 16-week collecting period, but trap elevation and distance to an infested hemlock did affect adelgid numbers. In Chapter III, we continued to assess the motorized trap’s performance across varied height and distance to an infested hemlock stand. We also determined how well a rapid molecular assay worked to detect HWA from the environmental samples caught by the trap. Again, trap distance to an infestation impacted trap capture success, but the height of a trap did not. The molecular assay reached a 0.9 probability of detecting HWA when a trap sample had approximately 14 adelgids present. This technology showed to be very promising as a monitoring tool for HWA and could help preserve valuable personnel and financial resources for HWA eradication efforts across its invasive range.

Download

Share

COinS