Squalene: A naturally abundant mammalian skin secretion and long distance tick-attractant (Acari : Ixodidae)

Squalene is a naturally occurring lipid on mammalian skin and is an attract ant to the lone star tick, Amblyomma americanum (L.). In this study, we com pared squalene to the standard tick-attractants, benzaldehyde, isobutyric a cid, methyl salicylate, nonanoic acid, and o-nitrophenol identified as acti ve ingredients of tick aggregation-attachment pheromones and determined its effectiveness in field and laboratory settings at varying distances. Squal ene was detected from 1/4 m greater than the standard tick attractants, att racted a greater percentage of ticks (75 compared with 0-43%) and featured a rapid response time (<30 min). Thus, squalene contributes more to the tic k's ability to locate hosts at greater distances than aggregation-attachmen t pheromones. These results have important implications for improving tick monitoring and control programs by adding squalene as a supplement to exist ing attractant baits.