The MSPCA recognizes the widespread concern regarding Lyme disease.  We also acknowledge the need for more information and education on the issue, how it is spread, and effective measures to reduce the number of infected ticks. As history has shown, increasing deer hunting seasons is not an effective way to successfully reduce the threat of Lyme disease.  In order to effectively reduce the number of Lyme disease cases, the number of disease carrying ticks needs to be reduced, not the number of deer. 

It is important to note that attempts to increase deer hunting will not reduce the threat of Lyme disease.

1.  Reducing the number of deer will not reduce the number of deer ticks

A 1993 study found that reducing the deer herd would not greatly reduce the number of ticks until the host density approaches zero. Reducing the herd will only result in more ticks per deer, not fewer ticks. Therefore, increasing deer hunting seasons will not successfully address the community’s concerns about tick-borne diseases.

2.    Reducing the deer herd will not reduce the number of ticks

Reducing the herd will not result in fewer ticks, only more ticks on fewer deer. In addition, hunting regulations to reduce the herd size usually focus on reducing the number of breeding females, when data has shown that bucks tend to carry more ticks than does.  It has been reported that “for whatever reason, bucks seem to be the more accommodating host for deer ticks; male deer have been shown to carry up to five times as many ticks as their female counterparts.”[i]

3. Adult ticks feeding on deer are not the greatest threat to humans

Deer ticks have a two-year life cycle with three stages: larvae, nymph and adult.  In the spring, eggs hatch into larvae, which are not born infected. However, if the larvae’s host (usually a mouse) is infected, it too may become infected.

When the larvae turn into a nymph in the fall, they usually feed on mice, small mammals and birds, not deer. According to the American Lyme Disease Foundation, due to its small size, an infected nymph tick can go unnoticed until they are fully engorged and “therefore responsible for the majority of human Lyme disease cases.”[ii] 

Adult ticks feed on deer, humans, pets and other large mammals. Female ticks feed for approximately one week, mate on or off of the host, drop off of the host and will lay approximately 2,000 to 3,000 eggs in the spring before dying.

If tick-borne diseases are to be successfully addressed, efforts need to focus on decreasing the number of ticks throughout their life cycle, not the number of hosts. 

Recommendations

The following tactics may be more effective in reducing the number of tick-borne diseases than increasing deer hunting seasons:

1. Increase public education    

Since ticks in the nymph stage have a greater potential for infecting people, communities should focus on increasing the means by which they educate people about ticks, how to reduce the chance of getting one, and what to do when people are bitten. The Massachusetts Department of Public Health recommends that people protect themselves from ticks by using repellents, staying out of tall grassy areas, and checking for ticks every day.

According to Assistant State Epidemiologist at Maine’s Department of Health and Human Services, education is the key to prevention because “a deer tick will not transmit Lyme disease if removed within 24 to 36 hours”[iii]

2. Install deer treatment bait stations

In order to target a larger percentage of ticks, deer treatment bait stations should be installed. The American Lyme Disease Foundation, Inc. sells a relatively inexpensive deer treatment bait station. Deer using the feeding station are forced to rub up against applicators that apply a pesticide to their ears, heads, necks and shoulders where approximately 90% of feeding adult ticks are attached.[iv]

3. Modify habitat to reduce the number of ticks in high-use areas

Habitat modification and pesticides can be used to reduce the number of ticks in recreational areas. Places with “low-lying vegetation, shrubs and grasses surrounding campgrounds or backyards should be close cropped or mowed to discourage tick movement and nesting. An approved residual insecticide should then be broadcast into the surrounding vegetation to establish an effective chemical barrier. A similar process, but on a smaller scale, can be followed for well-defined hiking trails.

Control should be aimed at the nymphal stage, which is the most likely stage to transmit the disease to humans. One application of a pesticide should be made at nymphal population peak. A second application toward the end of the nymphal stage, in late July to early August, is also suggested.”[v]

To manage tick numbers at the larval stage, a control device called Damminix Tick Tubes can be used. This device presents cotton balls treated with permethrin in cardboard tubes. “Mice take the cotton balls and use them in building nests. The mice are therefore exposed to enough pesticide to control the ticks that try to feed on them. Damminix is reported to be effective in reducing larval tick numbers and may have a place in an integrated tick management program. Commercial treatment of residential premises for tick control must be done by certified applicators.”[vi] Click here for information on Damminix Tick Tubes.

4.   4. Reduce habitat degradation

      There are several methods that can be used to address habitat degradation, including planting shrubs and plants that deer do not like to feed on; applying deer repellents and installing fencing.[vii]

The MSPCA’s Living With Wildlife program is committed to offering effective strategies that are long lasting and believes that reducing deer herds will not successfully address the tick-borne disease issue. We agree with the many professionals who recognize that this issue needs to be addressed through education, prevention, and innovative pesticide methods that directly affect the ticks.

For more information on Lyme disease, please visit the following:

American Lyme Disease Foundation

Massachusetts Department of Public Health

Center for Disease Control