Duration of repellency of various synthetic and plant-derived preparations for Culicoides imicola, the vector of African horse sickness virus.
Objectives of the study were threefold: to find a safer and longer lasting repellent of the biting midge Culicoides imicola than di-ethyl toluamide (DEET), to examine whether the current recommendations in Israel for application of repellents during an outbreak of C. imicola-borne pathogens are justified; and to examine whether plant-derived preparations that have no known detrimental side effects are potential replacements of synthetic repellents. Of the seven repellents tested, those inferior to DEET were: oregano and Herbipet which showed a slight non-significant repellency for 2 h and 1 h respectively and Stomoxin which showed significant (P < 0.05) repellency for only 1 h. As the active ingredient of Stomoxin is permethrin, this suggests that recommendations to spray animals with this insecticide to prevent the spread of C. imicola-borne pathogens are not useful. Tri-Tec14 showed significant (P < 0.05) repellency with respect to controls for 2 h only, but performed similarly to, or slightly better than DEET. The repellents clearly superior to DEET were: the plant-derived material Ag1000 that repelled significantly (P < 0.05) with respect to controls for up to 4 h following a similar pattern to but somewhat more strongly than DEET, and pyrethroid-T which exerted significant (P < 0.05) repellency for 9 h. Pyrethroid-T proved to be the best repellent tested and if sprayed nightly it might provide protection from C. imicola-borne pathogens.
Braverman
Y
Y
Kimron Veterinary Institute, Bet Dagan, Israel.
Chizov-Ginzburg
A
A
D000355:African Horse Sickness / Q000517:prevention & control*; D000818:Animals; D002519:Ceratopogonidae; D003671:DEET; D006736:Horses; D007299:Insect Bites and Stings / Q000150:complications / Q000517:prevention & control / Q000662:veterinary*; D007302:Insect Repellents; D007303:Insect Vectors; D007306:Insecticides; D019684:Magnoliopsida; D026023:Permethrin; D010936:Plant Extracts; D011722:Pyrethrins; D011897:Random Allocation
D007302:Insect Repellents; D007306:Insecticides; D010936:Plant Extracts; D011722:Pyrethrins; D003671:DEET; C017160:cypermethrin; D026023:Permethrin