Preventing Lyme Disease Through a Deeper Understanding of Tick Ecology

May 27, 2020

Preventing Lyme Disease Through a Deeper Understanding of Tick Ecology 

Linda Rieger in the woods Spring 2020

by Linda Rieger, Maryland Sierra Club Natural Places

With our spring treks outdoors, many people currently have a deep desire to make our exposure to Lyme Disease less likely. Maryland Sierra Club’s Natural Places team has long had an emphasis on both removing invasive weeds and encouraging native plants, activities that promote healthy ecosystems that also can decrease the incidence of Lyme disease if done correctly. The bacillus which causes Lyme disease is in the white-footed mouse and birds and larger mammals. An understanding of the underlying ecology of lyme transmission to humans will help prevent it to the greatest extent possible. 

tick lifecycleTick larvae are mostly found on the white footed mouse in the summer, and that is where the ticks grow and pick up the bacillus.  If you can break the cycle there, you have stopped the exposure to Lyme Disease.  Unfortunately, the white footed mouse likes to make its nest in the roots of either the prickly plants or in the dense roots of the invasive plants that we are working to remove.  The mice make their nests there because their predators are less likely to get them or their young in those places. Who wants to get into the briar patch?!  

The very plants that we are trying to remove (Japanese barberry and Japanese bush honeysuckle, among others) are where the tick larvae are living on the mice from which they will eventually transfer to us to get their blood meal.  In another other part of the cycle, the tick crawls up on flora to be able to reach and get on to the deer. The deer move around the area where the tick drops to the tall grasses and attaches finally to us as we walk through the grass. 

So, what can we do?  We can do seven things. Let us look at the implications for each of these options.   

  1. 1. Reduce the number of mice. If we remove the prickly invasive plants, it will allow the predators to catch more mice, letting nature take care of itself.  Hawks, fox, and owls will love those juicy mice.  If you stay on the paths, you will not scare away the predators that consume the mice. 

Removing invasive honeysuckle Lonicera maackii by Lily Fountain

 2. Protect yourself from any ticks that land on your clothes.  One  way to reduce danger from ticks is to use an insecticide on your clothes especially boots, socks, and pants, and gear.  Permethrin has been used by the U. S. military and the Boy Scouts carefully for many years.  The CDC and WHO recommends its use before people travel into tick and mosquito infested areas.  There are caveats about the proper use of permethrins.  It should only be used on clothes or by purchasing clothes already impregnated with it.  It should never be sprayed onto a person’s skin or put near your skin while the clothing is still wet. 

The proper way to put it on clothing is to spray it on during a clear day that has no wind and where there will be no run-off.  Permethrin will kill fish.  It will hurt cats.  You can put on the clothes a day after the clothing is sprayed and it will last for around10 washings.  Refer to manufacturer guidelines for the duration of effectiveness for permethrin coatings on clothing and follow the instructions for safe application.

You can use Lemon Eucalyptus or another insect repellent on your clothes on the day you go out if you haven’t had time to safely and properly apply permethrin ahead of time.

3. Reduce the numbers of ticks on mice.  Tick tubes are an option to reduce the tick larvae on the mice.  These are just tubes like toilet paper rolls that have permethrin-soaked and dried cotton balls inside them.  The tubes are placed in areas where you have mice, but not near ponds or streams or where there is heavy run-off.  They should be placed where children and pets will not play with them, such as under a prickly or dense bush.  The mice like to use the cotton balls as material for their nests.  The permethrin kills the ticks, but it does not hurt the mice.  My son and I have used these tick tubes, and they do work.

4. Reduce the overpopulation of deer. There will always be some ticks that get away and find themselves out into the native environment.  If you are lucky, you may have an opossum that likes to eat them.  If not, the ticks are looking for a blood meal so they can reproduce.   If there are a lot of mammals around they will serve in part of the cycle. You are most likely to get the tick because of an overpopulation of deer.  In areas where the deer population has been reduced, the Lyme Disease infections go down as well. If deer are reduced to a natural density of about 20 per square mile, in addition to preserving the native plants and animals in the natural ecosystem, lyme disease will essentially go away.

Deer Crossing by Richard Winston

5. Reduce conditions for ticks in your yard and be vigilant about keeping ticks off us. Whether or not there are lots of deer around, keeping the tall flora (grass) cut in your yard will help.  It will reduce the opportunity for the ticks to get on you.  Wearing long light-colored pants tucked into light-colored socks, you will be able to see the ticks before they latch onto you for their blood meal.

6. Be vigilant about removing ticks from our bodies before they infect us with the bacillus. When you come in from outdoors, make sure you take a bath, and inspect your body. Or better yet have someone else inspect your body. Ticks will migrate to your private parts, under your arms and toward your hairline.  This inspection can get quite interesting! Put your clothes in the washing machine and finally, in the dryer at a high temperature.

 7. Treat Lyme Disease quickly before it becomes chronic. If you miss a tick on the first inspection, (it could happen since they are tiny), remove it carefully as close the mouth parts as possible. The “deer tick” is about the size of a sesame seed.  Save it and take it to the doctor.  You will probably need a round of doxycycline.  Even if you do not yet have symptoms, it is best to start the antibiotic while the tick (and/or you) are being tested.  If your Lyme Disease becomes chronic, you may have these symptoms:  extreme fatigue, anxiety, increase in immune processes, non-functionality (bed-ridden).  This is serious!

 

Tick bite with bullseye by Lily Fountain

Dr. Mark J. Soloski heads the Lyme Research Center at Johns Hopkins University.  He has declared that “Lyme Disease is the #1 vector-bourne disease in the United States.”  The tick must be removed from a human in at least the first 36 hours before transmitting the bacillus for the disease.  People may not have common symptoms like a bulls-eye rash.  A fever or aching joints may be the first symptoms noticed. Then the bacillus must be treated aggressively, most likely with doxycycline (under a doctor’s order).  If the round of the antibiotic that is chosen does not clear the bacillus, advanced Lyme Disease may become a chronic disease.  With advanced Lyme, the person may have unchecked fatigue, anxiety, increased immune processes and become literally non-functional.   Several local universities are looking into the problem, including Virginia Tech, the University of Maryland and, of course, Johns Hopkins University. 

Good luck to you and your family in preventing Lyme Disease!

Victory over invasives by Richard Winston

Contributed by Linda Rieger with Maryland Sierra Club Natural Places

You may contact Linda via email at lindarieger [@] verizon.net 

More Lyme Disease Resources

Here are some further great lyme disease resources. Thanks to Marc Imlay and Kasha Helget (Kasha.Helget@outlook.com). 

Scientific American: The link between Japanese barberry and Lyme disease https://blogs.scientificamerican.com/guest-blog/barberry-bambi-and-bugs-the-link-between-japanese-barberry-and-lyme-disease/