Developing attractants and repellents for ticks: promises and challenges.

Historically, some of the most effective tools to counter vector-borne diseases have been those directed against the vectors. Ticks are undergoing a population explosion as evidenced by the recent expansion of their distribution range. Tick control has traditionally relied heavily on pesticides. However, sustained use of acaricides is resulting in resistant tick populations. Multipronged management strategies that build and expand upon innovative control methods are sorely needed. Behavior-modifying chemicals, referred to as semiochemicals, such as pheromones and repellents, offer a first line of personal protection against ticks. We review the current understanding of tick semiochemicals, and how such understanding is leading to the identification of novel chemistries that are effective and safe.