Date of Award

Summer 8-2015

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Entomology

Advisor

Eleanor Groden

Second Committee Member

Francis Drummond

Third Committee Member

Joseph Elkinton

Abstract

This project examines the recent outbreak of the invasive winter moth (Operophtera brumata) in mid-coast Maine. The winter moth was introduced into New England in the late 1990’s and low densities of winter moth were detected with pheromone traps throughout the Maine coast in 2006. Severe defoliation occurred for the first time in Maine in the spring of 2012 in Harpswell and Vinalhaven, ME. This pest attacks an extremely broad range of host plants, including forest hardwood trees and agricultural crops such as highbush blueberry and apple. The objectives of this study are to examine the differential development and survival of the winter moth on common hardwood forest trees as well as important agricultural crops, to determine the insect phenology in relation to host plants throughout the year in Maine, to monitor the relative population densities on different host plants, and to survey Maine winter moth for pathogens already present in the population. We found that larval survival and densities are significantly higher on red oak and apple trees and lowest on pin cherry. Larval survival is significantly higher when egg hatch is closely synchronized with host plant bud burst. Lastly, using molecular markers, we inferred the presence of winter moth nucleopolyhedrovirus in larvae collected from seven different host plants, including wild lowbush blueberry. Larvae were observed feeding on wild lowbush blueberry, a new host for this species. While larval survival and densities are lower on lowbush blueberry than on oak and apple, they readily feed on and cause severe damage to wild blueberry when populations are at outbreak levels. Through studying the biology of this insect, we are able to determine the factors that are closely linked to its survival in the hopes of developing methods of control before seeing irreparable damage to Maine’s forests and agriculture.

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