LE3 .A278 2021

2021

Faraone, Nicoletta

Acadia University

Bachelor of Science

Honours

Chemistry

Chemistry

Ticks, such as blacklegged tick (Ixodes scapularis) and American dog tick (Dermacentor variabilis) are vectors of several pathogens that negatively impact animal and human health. In recent years due to global warming, the threat of disease transmission has risen significantly, resulting in an increased demand for environmentally safe, tick repellent and acaricidal products. Natural products, such as essential oils and inert rock dust, are prospective alternatives to manage these pests. Basil (Ocimum basilicum, L.) has been reported to have promising pest repellent activity. I have extracted essential oils from different basil varieties through hydrodistillation and I have characterized the chemical composition of the oils through GC-MS. Basil essential oils were tested for long-term repellent activity towards nymphs of blacklegged ticks using horizontal bioassays at different concentrations. In addition, I combined basil essential oils with an inert material (i.e., granite rock dust) with known insecticidal properties to assess acaricidal activities against adult ticks. Among the tested basil varieties, Jolina essential oils (at the concentration of 15% v/v) repelled 96% of tested ticks up to 2 hours post-treatment. In acaricidal tests, the combination of essential oils from Aroma2 var. at concentration of 10% w/w with rock dust resulted in 100% tick mortality after only 24 hrs post-exposure. In the effort to protect essential oils and enhance their bioactivity, I have encapsulated a mix of extracted basil essential oils in equal ratio through nanoemulsification followed by spray-drying. The obtained powder provided a stable product with an encapsulation efficiency approximately equal to 100%. The use of essential oils alone, and in combination with rock dust, and the possibility to enhance essential oil properties through nanoencapsulation represent an innovative and environmentally-friendly approach to manage ticks and the spread of vector-borne diseases.

The author retains copyright in this thesis. Any substantial copying or any other actions that exceed fair dealing or other exceptions in the Copyright Act require the permission of the author.

https://scholar.acadiau.ca/islandora/object/theses:3579