title: DEET (N,N-diethyl-meta-toluamide)/PMD (para-menthane-3,8-diol) repellent-treated mesh increases Culicoides catches in light traps.
abstract: Biting midges (Culicoides spp.) are vectors of bluetongue and Schmallenberg viruses. Treatment of mesh barriers is a common method for preventing insect-vectored diseases and has been proposed as a means of limiting Culicoides ingression into buildings or livestock transporters. Assessments using animals are costly, logistically difficult and subject to ethical approval. Therefore, initial screening of test repellents/insecticides was made by applying treatments to mesh (2 mm) cages surrounding Onderstepoort light traps. Five commercial treatments were applied to cages as per manufacturers' application rates: control (water), bendiocarb, DEET/p-menthane-3,8-diol (PMD) repellent, Flygo (a terpenoid based repellent) and lambda-cyhalothrin. The experimental design was a 5 × 5 Latin square, replicated in time and repeated twice. Incongruously, the traps surrounded by DEET/PMD repellent-treated mesh caught three to four times more Obsoletus group Culicoides (the commonest midge group) than the other treatments. A proposed hypothesis is that Obsoletus group Culicoides are showing a dose response to DEET/PMD, being attracted at low concentrations and repelled at higher concentrations but that the strong light attraction from the Onderstepoort trap was sufficient to overcome close-range repellence. This study does not imply that DEET/PMD is an ineffective repellent for Culicoides midges in the presence of an animal but rather that caution should be applied to the interpretation of light trap bioassays.
authors.affiliation: Agri-Food and Biosciences Institute, Newforge Lane, Belfast, BT9 5PX, Northern Ireland. archie.murchie@afbini.gov.uk.
authors.forename: A K
authors.initials: AK
authors.lastname: Murchie
authors.affiliation: Agri-Food and Biosciences Institute, Newforge Lane, Belfast, BT9 5PX, Northern Ireland.
authors.forename: S
authors.initials: S
authors.lastname: Clawson
authors.affiliation: Agri-Food and Biosciences Institute, Newforge Lane, Belfast, BT9 5PX, Northern Ireland.
authors.forename: I
authors.initials: I
authors.lastname: Rea
authors.affiliation: Agri-Food and Biosciences Institute, Newforge Lane, Belfast, BT9 5PX, Northern Ireland.
authors.forename: I W N
authors.initials: IW
authors.lastname: Forsythe
authors.affiliation: Agri-Food and Biosciences Institute, Newforge Lane, Belfast, BT9 5PX, Northern Ireland.
authors.forename: A W
authors.initials: AW
authors.lastname: Gordon
authors.affiliation: Agri-Food and Biosciences Institute, Newforge Lane, Belfast, BT9 5PX, Northern Ireland.
authors.forename: S
authors.initials: S
authors.lastname: Jess
mesh_terms: D000818:Animals; D001819:Bluetongue / Q000635:transmission; D002519:Ceratopogonidae / Q000187:drug effects* / Q000821:virology; D000081005:Cyclohexane Monoterpenes; D003671:DEET / Q000494:pharmacology*; D007302:Insect Repellents / Q000494:pharmacology*; D007303:Insect Vectors / Q000187:drug effects; D007306:Insecticides / Q000494:pharmacology; D008610:Menthol / Q000031:analogs & derivatives* / Q000494:pharmacology; D009570:Nitriles / Q000494:pharmacology*; D048448:Phenylcarbamates / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology; D011722:Pyrethrins / Q000494:pharmacology*; D012756:Sheep; D013729:Terpenes / Q000494:pharmacology*
chemical_list: D000081005:Cyclohexane Monoterpenes; D007302:Insect Repellents; D007306:Insecticides; D009570:Nitriles; D048448:Phenylcarbamates; D010936:Plant Extracts; D011722:Pyrethrins; D013729:Terpenes; D003671:DEET; D008610:Menthol; C005804:terpin; C007725:bendiocarb; C037304:cyhalothrin
keywords: Attractant; Culicoides; DEET; Onderstepoort light trap; Repellent; p-Menthane-3,8-diol