Short Lecture "Investigating the Insect Repellency of an Irish Bog Plant, Bog Myrtle (Myrica gale L.)

Bog myrtle (BM) (Myrica gale L.), is a shrub with a wide occurrence across the northern hemisphere, particularly in Irish boglands. Bogs provide critical functions for hydrology, biodiversity and climate. Currently in Ireland there is a drive towards developing a bioeconomy, with the discovery of sustainable natural products from Irish biodiversity being of priority. In the quest for innovation with the natural product environment, the first step is often rooted in ethnobotanical and ethnopharmacological uses of species. Irish and international folklore reports use of BM for the determent of various insects such as midges [1] [2] [3].

This study aimed to enrich the knowledge surrounding BM and its potential as a natural insect repellent. After reporting systematic chemical profiling and anti-cholinesterase activity of essential oil samples (EOs), extracted from BM from a range of locations, plant parts and seasons [4] [5], work was advanced to testing for repellency. EOs with varied chemical profiles, their fractionated components, and a variety of combinations, were screened for repellency using arm-in-cage and Y-tube assays against Aedes aegypti mosquitoes. Results for BM-EO repellency showed great variance across all samples, dependent on chemical composition, with complete protection time (CPT) for contact repellency ranging from 7.22 – 36.02 minutes and 0 ->240 minutes for long-distance repellency. Furthermore, CPT for BM was altered when EOs were combined with other oils and individual compounds. The best performing combination was BM and commercial clove oil (1:1) ratio. This study corroborates the traditional use of BM in deterring insects. Further studies are underway.

Publikationsverlauf

Artikel online veröffentlicht:
16. November 2023

• References

• 1 Hart H.C.. The Flora of the County Donegal. Sealy, Bryers and Walker, Dublin 1898
• 2 Williams N. Díolaim luibheanna. Sáirséal-Ó Marcaigh, Baile Atha Cliath 1993
• 3 Allen E.D., Hatfield G.. Medicinal Plants in Folk Tradition. Timber Press 2004
• 4 Pigott M., Nagar S., Woulfe I., Scalabrino G., Sheridan H.. Unlocking Nature’s Pharmacy: Composition and bioactivity of essential oil of bog-myrtle (Myrica gale) grown on Irish boglands. Planta Medica 2022; 88 (15) 1521-1521
• 5 Nagar S., Pigott M., Whyms S., Berlemont A., Sheridan H.. Effect of Extraction Methods on Essential Oil Composition: A Case Study of Irish Bog Myrtle-Myrica gale L. Separations 2023; 10 (02) 128