Effect of different headspace concentrations of bornyl acetate on fecundity of green peach aphid and balsam woolly adelgid

ABSTRACT

Balsam woolly adelgid (Adelges piceae) (Hemiptera: Adelgidae) (BWA) is an exotic pest introduced from Europe to North America in the early 1900s. Subsequent introductions and spread have enabled this pest to infest native Fraser fir stands in the Southern Appalachians and become a troublesome pest for the region’s Christmas tree industry. Means to study its fecundity and control it are consequently of high importance. Headspace solid phase micro-extraction coupled with gas chromatography and mass spectrometry were used to compare chemical differences in stem tissue between a resistant species, Veitch fir (Abies veitchii) and the susceptible Fraser fir (Abies fraseri). Comparisons demonstrated that bornyl acetate (BA), a terpenoid, was qualitatively more abundant in resistant Veitch fir than Fraser fir. Varying headspace concentrations of BA were tested to ascertain any biological impacts on egg eclosion of BWA, as well as fecundity of green peach aphid (Myzus persicae) (GPA), an insect serving as a proxy. Varying concentrations of BA and a known number of adelgid eggs did not indicate any impact of concentration on egg eclosion success. However, defoliated Veitch fir branches in treatment jars produced a significant negative impact on BWA eclosion success. Implications of these findings are discussed.

KEYWORDS:

• Invasive insects
• chemical biology
• Fraser fir
• Veitch fir
• Adelges piceae
• Myzus persicae

Acknowledgements

We would like to thank to thank Alejandro Merchan, PhD student in the Entomology Department at NC State for providing us with green peach aphid from his experiments. Special thanks to Travis Birdsell and Brad Edwards of the North Carolina Cooperative Extension Service, for helping us locate and collect infested Fraser fir logs. A final thanks is extended to Catherine Bucholz for helping collect infested Fraser fir logs and Veitch and Fraser fir branches.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was largely funded by the North Carolina Agricultural Research Service via the Christmas Tree Genetics Program.