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Providing evidence to improve practice

Individual study: Effects of treatment with diatomaceous earth on numbers of ectoparasites in nests of tree swallows Tachycineta bicolor near Prince George, British Columbia, Canada

Published source details

Dawson R.D. (2004) Efficacy of diatomaceous earth at reducing populations of nest-dwelling ectoparasites in tree swallows. Journal of Field Ornithology, 75, 232-238


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Remove ectoparasites from nests to increase survival or reproductive success Bird Conservation

A randomised, replicated and controlled trial over two breeding seasons in 2001-2 in British Columbia, Canada (Dawson 2004) found that tree swallow Tachycineta bicolor nests treated with insecticide (in 2001: 38.1% diatomaceous earth, 0.2% pyrethrins and 1.0% piperonyl butoxide; 2002: 80% silicon dioxide) contained significantly fewer bird fleas Ceratophyllus idius and blow flies Protocalliphora spp. than untreated nests (approximately 25 fleas and 28 blowflies in 23 treated nests vs. 350 fleas and 50 blowflies in 32 control nests).