Document Type

Honors Thesis

Major

Botany

Advisor(s)

Barbara Cole, Angela Mech

Committee Members

Karl Bishop, Philip Fanning, Melissa Ladenheim

Graduation Year

May 2021

Publication Date

Spring 5-2021

Abstract

The browntail moth (BTM; Euproctis chrysorrhoea)is a non-native, invasive species that has recently become a serious human health and environmental concern in Maine. BTM caterpillars possess microscopic toxic hairs that cause a poison-ivy-like rash on the skin and have been known to cause respiratory discomfort when inhaled. This invasive species is an herbivorous insect that causes harm to its host tree through defoliation during its larval life stage. BTM larvae weave overwintering webs on branch tips, generally at the tops of hardwood trees. Due to their toxic hairs and where they establish their overwintering webs, the species population is difficult to manage. Previous research indicates that commercial insecticides containing terpenes, natural plant defensive compounds, inhibit or kill BTM larvae. Many of the terpenes that have been tested are present in various conifer tree species. Therefore, I investigated the influence of terpenes from balsam fir (Abies balsamea), white pine (Pinus strobus), red spruce (Picea rubens), and northern white cedar (Thuja occidentalis) on browntail moth larval feeding.These conifer terpenes were extracted by means of steam distillation from needles and applied to BTM larval food sources in a laboratory setting. This research project also analyzed the terpene composition of the distillate samples by means of Gas Chromatography–Mass Spectrometry analysis. Results showed that the concentration and methodology used to evaluate conifer terpene distillates did not have a significant effect on the feeding habits of BTM larvae.

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