title: Essential oil analysis and field evaluation of the citrosa plant "Pelargonium citrosum" as a repellent against populations of Aedes mosquitoes.
abstract: A plant recently introduced into North America as the citrosa, Pelargonium citrosum ('Van Leenii'), has been marketed as a biological repellent against mosquitoes. Citrosa is claimed to repel mosquitoes within a 10 ft.2 (0.93 m2) area due to a continuous fragrant release of citronella oil. The total essential oil yield was 0.2 +/- 0.1% from fresh plant material. Chemical analysis by the authors revealed that combined essential oils of fresh greenhouse- and field-grown citrosa have 35.4 +/- 6.2% geraniol, 10.4 +/- 1.6% citronellol, 8.9 +/- 2.0% isomenthone, and 6.8 +/- 3.8% linalool. Both the morphology and essential oil of citrosa fall within the Pelargonium x asperum hybrid complex and are similar to 'Rosé', the commercial rose geranium. No character of morphology or essential oil of a Cymbopogon species yielding commercial citronella oil could be detected in the citrosa. The effectiveness of the citrosa as a repellent against field populations of spring Aedes spp. mosquitoes was evaluated and compared with a 75% deet (N,N-diethyl-3-methylbenzamide) formulation. Deet provided > 90% reduction in mosquitoes biting subjects for up to 8 h post-treatment. There was no significant difference between citrosa-treated and nontreated subjects.
authors.affiliation: Department of Environmental Biology, University of Guelph, Ontario, Canada.
authors.forename: B M
authors.initials: BM
authors.lastname: Matsuda
authors.forename: G A
authors.initials: GA
authors.lastname: Surgeoner
authors.forename: J D
authors.initials: JD
authors.lastname: Heal
authors.forename: A O
authors.initials: AO
authors.lastname: Tucker
authors.forename: M J
authors.initials: MJ
authors.lastname: Maciarello
mesh_terms: D000328:Adult; D000330:Aedes; D000818:Animals; D005260:Female; D006801:Humans; D007302:Insect Repellents; D008297:Male; D009032:Mosquito Control; D010938:Plant Oils / Q000032:analysis; D010944:Plants
chemical_list: D007302:Insect Repellents; D010938:Plant Oils