Essential oils as repellents for controlling house flies (Musca domestica L.) in organic dairy operations

Pradeep Nampoothiry^1*, Simon Lachance², Cynthia Scott Dupree¹, Ron Harris¹ and Rebecca Hallet¹
(1) School of Environmental Sciences, University of Guelph, Guelph ON, N1G 2W1,
(2)Organic Dairy Research Centre, University of Guelph – Alfred campus, Alfred, ON, K0B 1A0.
*Presenter, pnampoot@uoguelph.ca

Abstract
The house fly (Musca domestica L.) is a major pest of dairy cattle because of its potential to spread diseases, and reduce feeding efficiency and milk production in livestock. Synthetic insecticides cannot be used in organic dairy operations and hence there is a need for alternate strategies to control these flies. Some essential oils are known to cause repellency and mortality of insect pests.

Six essential oils – basil, geranium, pine, peppermint, lavender and lemongrass were studied in laboratory and barn bioassays to determine their comparative repellent effect on house flies. Laboratory binary choice bioassay using 4 doses smeared on a sugar coated slide (bait) were performed. All oils, except pine and peppermint at the highest dose (42.8 µl/slide), exhibited 100% repellency for a 10 min period after the treatment. Basil, geranium and lemongrass at 6.7 µl/slide resulted in 100, 93 and 86% repellence, respectively. Twenty-four h after treatment, geranium oil continued to effectively repel 96% of flies at the higher dose. The effects of all the oils waned after 72 h.

In a barn bioassay, all 6 oils along with a low risk organically certified insecticide (spinosad – Entrust®, Dow Agroscience Canada Inc.) and a conventional pyrethrin (1.8% pyrethrins - Konk®, AirGuard Control (Canada Ltd.) were applied to an attractive substrate (a mix of wheat bran, milk powder, blood meal, yeast and water) at 5 different doses.  The treated substrate was placed in a barn and observed over a 6 h period. Barring pine, the oils repelled more than 98% of flies at 50 µl/g. Geranium and lemongrass at 25 and 11.11 µl/g repelled more than 95 and 80% of flies, respectively. Spinosad had very little repellent effect, while the pyrethrin was highly repellant. The effective repellency of house flies by essential oils could be combined with attractant traps to devise a novel push-pull strategy that will aid in sustainable pest management of these insect pests in organic dairy operations.


Abstract of presentation given at the 2010 Guelph Organic Conference Natural Sciences Research Symposium.


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Posted March 2010