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Repellency of deet and SS220 applied to skin involves olfactory sensing by two species of ticks
Author(s) -
Carroll J. F.,
Klun J. A.,
Debboun M.
Publication year - 2005
Publication title -
medical and veterinary entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 82
eISSN - 1365-2915
pISSN - 0269-283X
DOI - 10.1111/j.0269-283x.2005.00559.x
Subject(s) - deet , amblyomma americanum , tick , ixodidae , ixodes scapularis , biology , acari , nymph , bioassay , acaricide , zoology , toxicology , ecology
. Responses of host‐seeking nymphs of the blacklegged tick, Ixodes scapularis Say and lone star tick, Amblyomma americanum (Linnaeus) (Acari: Ixodidae) to the repellents N,N‐diethyl‐3‐methylbenzamide (deet) and (1S, 2′S)‐2‐methylpiperidinyl‐3‐cyclohexene‐1‐carboxamide (SS220) were studied using fingertip laboratory bioassays. Ethanol solutions of both compounds applied to the skin strongly repelled both species of ticks at 0.8 and 1.6 µmole of compound/cm 2 skin. The ticks were also repelled when two layers of organdie cloth covered the portion of a finger treated with either deet or SS220. Gas chromatographic analyses of the outer layer of cloth that had covered skin treated with 1.6 µmole compound/cm 2 skin revealed only 0.1 nmole SS220/cm 2 cloth and 2.8 nmole deet/cm 2 cloth. However, in bioassays in which a single layer of cloth was treated with a dose of deet or SS220 equivalent to the amount found in the outer layer of cloth, ticks were not repelled. Results unequivocally demonstrated that these ticks responded to the repellents in the vapour phase when repellent treated skin was covered with cloth to obviate tactile contact with them, and made it clear that the ticks detect the repellents by olfactory sensing. Heretofore, the mode of action of deet and SS220 was unclear.