Targeting hosts to stop the spread of ticks

Improvements to bait boxes — a tool used to kill ticks on mice and chipmunks — can successfully lower the prevalence of ticks in the rodents, according to new research.

These bait boxes, which leave insecticide on tick hosts when they emerge, were first produced in 2002, but they were recently improved so that it’s harder for squirrels and large animals to damage them.

As part of the new study published in the Journal of Medical Entomology, researchers tested the improved design of the SELECT Tick Control System (TCS) on residential properties in New Jersey in 2012 and 2014.

They deployed the bait boxes on 12 residential properties adjacent to woodlands in 2012 and 10 properties in 2013 and periodically returned to check how many animals visited each box. Then, they trapped mice and chipmunks in areas with and without bait boxes and counted the ticks on them.

The team found that the improved bait boxes reduced tick prevalence in mice and chipmunks. Ticks in the treated properties were reduced by 97 percent after two years.

“These results demonstrate that SELECT TCS may provide a significant reduction in human exposure to host-seeking ticks, while reducing the use of pesticide compared to traditional area-wide chemical control,” said study co-author Robert Jordan, a research scientist with the mosquito control division of Monmouth County, N.J., and a TWS member.

Because the bait boxes target only specific life stages of ticks that have already acquired a host, however, Jordan said, significant tick reductions may not appear until months or years after the boxes are deployed. “Such lag times may affect their widespread public acceptance and commercial use,” he said.

Jordan said future research should look at other species, such as shrews, which were not effectively sampled, and on the effect of the bait boxes on tick-borne disease prevalence.