DEVELOPMENT OF A METHOD FOR EVALUATING TICK ATTRACTANTS IN THE FIELD

Authors: Carroll, John; SOLBERG, V - SILVER SPRING, MD; Cyr, Tracy

Submitted to: Proceedings of the Entomological Society of Washington
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2005
Publication Date: 1/5/2006
Citation: Carroll, J.F., Solberg, V.B., Cyr, T.L. 2006. Development of a method for evaluating tick attractants in the field. Proceedings of the Entomological Society of Washington. 108:82-91.

Interpretive Summary: Ticks and tick-borne diseases cause serious medical and economic problems in the U.S. and abroad. Tick attractants are useful for surveillance for some important species of ticks and are being investigated for use with insecticides to reduce tick populations. Evauating experimental tick attractants against natural populations has some weaknesses, because host-seeking ticks tend to be unevenly distributed, even within a habitat type. We developed an altenrative method of evaluating tick attractants, testing it using dry ice (carbon dioxide, a known tick attractant). By releasing known numbers of ticks at locations on a sheet downwind of dry ice and recapturing them after one hour, we were able to consistently discriminate between tick responses to dry ice and untreated controls. These findings are of interest to researchers and private industry involved in the development of attractants for monitoring tick and insect populations and bait-toxicants for control purposes.

Technical Abstract: A method for testing tick attractants under field conditions is described. Inconclusive results of evaluations of expeimental baits on natural populations that are generally unevenly distributed, even within habitat types, can be avoided by releasing known numbers of ticks at predetermined locations and distances downwind from a bait. Lone star tick, Amblyomma americanum, nymphs were released directly downwind of dry ice baits on large (2.25 x 2.25 m) cotton sheets aligned with the direction of the wind and edged with a masking tape barrier. Best results in discriminating between dry baits and untreated controls were in a zone 0.3-1 m from the bait when ticks were released 1.01-1.5 m from the bait. The success of this method, or any using an air-borne attractant, depends on the wind not stopping for prolonged periods or radically changing direction.