Efficacy of plant-derived and synthetic compounds on clothing as repellents against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae).
We conducted field trials to compare the relative repellent activity of two natural product compounds (nootkatone and carvacrol) with commercially available plant-derived (EcoSMART organic insect repellent) and permethrin-based (Repel Permanone) repellents against adult Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae) by using treated coveralls. One day after treatment, nootkatone and carvacrol provided 100% repellency of I. scapularis adults, with nootkatone maintaining complete protection through 3 d, whereas carvacrol showed steadily declining repellency against I. scapularis during the 7-d course of the trials. Nootkatone was at least as effective against host-seeking A. americanum as against I. scapularis through 3 d. Carvacrol provided little protection against A. americanum adults. Both natural compounds performed well initially in comparison with the commercial products. After 7 d, nootkatone was the most effective against both species followed in order of activity by Permanone, EcoSMART, and carvacrol. Nootkatone seems to have offer considerable potential as a clothing repellent against both I. scapularis and A. americanum.
Freehold Area Health Department, 1 Municipal Plaza, Freehold, NJ 07728, USA. rajordanphd@optimum.net
Robert A
RA
Jordan
Terry L
TL
Schulze
Marc C
MC
Dolan
D000818:Animals; D003020:Clothing; D000081007:Cymenes; D007302:Insect Repellents / Q000737:chemistry* / Q000494:pharmacology*; D026863:Ixodidae / Q000187:drug effects*; D039821:Monoterpenes / Q000737:chemistry / Q000494:pharmacology*; D026023:Permethrin / Q000737:chemistry / Q000494:pharmacology; D010944:Plants / Q000737:chemistry*; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes / Q000737:chemistry / Q000494:pharmacology*; D013983:Tick Control
D000081007:Cymenes; D007302:Insect Repellents; D039821:Monoterpenes; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes; D026023:Permethrin; C073316:carvacrol; C050302:nootkatone