Despite their miniscule size, they can cause a lot of trouble, and they’re on the move. Where once there were relatively few ticks, there are now many, and a higher percentage of them carry disease. Who are these travelers, why do you not want one as your personal houseguest, and what can you do if one moves in unbidden?
Many species of ticks live in the northeastern U.S. New Hampshire alone has 15, including blacklegged ticks, the ones that spread Lyme disease. “In all the activities of farming, ticks sometimes fall off the radar,” said Alan Eaton, a University of New Hampshire Cooperative Extension professor and entomology specialist. “If you don’t think about ticks, you are the perfect victim,” he warned.Here’s what you need to know about ticks to avoid being a victim:
- Ticks can be active all year, even throughout mild winters. The time of greatest risk for humans is between about May 15 and July 10, but in wetter years, this period may be extended. Ticks are also active in October and November.
- A daily personal all-body check and prompt removal of ticks are the best ways to avoid illness.
Questing for you
Ticks are most likely to be found in tall grass and in brush, and most hang out about 4 inches above the ground. On the farm, those areas include hayfields and the edges of cultivated areas, particularly places where insecticides are not used more than once or twice a year. Ticks can also be found in ornamentals, including hedges, and in certain ground covers like creeping charlie. Mowed lawns are not ideal tick habitat, but the untended edges are.
As you (or any warm-blooded animal) walk through tick habitat, a tick may hitch a ride and seek lunch. Although most ticks cannot see — they have no eyes — they respond to touch. When they’re seeking a host, they hold their front legs out (a stance termed “questing”), ready to grab any potential host passing by. Ticks do not drop out of trees; tree canopies are too dry to be suitable habitat for most ticks.
Tick baggage: What ticks carry and how it can affect you
Blacklegged ticks, Ixodes scapularis (formerly known as deer ticks), can spread not only Lyme disease, but also the microorganisms that cause two other serious illnesses, anaplasmosis and babesiosis. Anaplasmosis is a serious, often fatal illness involving white blood cells. It generally affects people over age 60. Babesiosis is a disease similar to malaria, which attacks red blood cells. It can be treated with an antibiotic plus an antiparasitic drug. Between 2008 and 2011, New Hampshire (whose then third-place ranking of Lyme disease incidence has now risen to first) saw 43 cases of babesiosis, 79 of anaplasmosis, and 5,569 reported cases of Lyme disease.
Lyme disease is the most common tick-borne illness. Left untreated, it can cause extreme fatigue, joint problems (especially in the knees), heart arrhythmias, and Bell’s palsy, a form of facial paralysis resulting in the inability to control the muscles on the affected side of the face. In earlier phases, symptoms may resemble the flu.
Life cycle and hosts
With the notable exception of winter tick (the one-host tick that plagues moose), most ticks found in the northeastern U.S. require three blood meals in order to complete their two-year life cycle. Beginning as eggs laid on leaf litter, ticks
hatch into six-legged larvae from which they morph into eight-legged nymphs, and then adults. After the third and final blood meal, adult female ticks lay their eggs, which may number in the hundreds. As female ticks lay their eggs, they get smaller and smaller, and then they die.
Blacklegged ticks acquire Borrelia burgdorferi, the bacterium that causes Lyme disease, as they dine on an infected reservoir host. Reservoir hosts provide places for B. burgdorferi spirochetes (corkscrew-shaped bacteria) to multiply. White-footed mice are the most common reservoir hosts of B. burgdorferi, but chipmunks and robins can also be carriers. Blacklegged tick nymphs, no larger than a poppy seed, are the most common transmitters of Lyme disease. Only about 1 millimeter in size, blacklegged tick nymphs are much smaller than adults. Adults resemble a sesame seed in size and shape.
The spread of Lyme disease begins when the larva or nymph of a blacklegged tick feeds on a reservoir host infected with the spirochetes. Weeks later, after the tick has digested the blood meal from the reservoir host and is feeding again, the spirochetes move from within the tick’s gut to its blood, and then into its salivary glands. As the tick feeds, the spirochetes are ejected from its salivary glands and injected into a host (which could be you). Nymphs can transmit disease within 24 hours of feeding. If you find and remove your unwanted diner before 24 hours have elapsed, Eaton said, “You can lessen your chances of acquiring Lyme disease from that bite to near zero.”
Symptoms of Lyme disease
Within three to 32 days after a tick bite, a red, spreading rash that’s warm to the touch may appear at the bite site. The rash, called erythema chronicum migrans (ECM), does not begin immediately after the bite and tends to fade as it spreads. It does not always appear in concentric rings, and it appears in only about 40 percent of people who get Lyme disease. “People frequently confuse the red spot formed during biting with ECM,” Eaton noted.
From a few days to weeks after infection, fatigue, fever, headaches, stiffness, and muscle and joint pain often occur. Left untreated, Lyme disease can affect people from several months to years after infection.
Reducing your odds of getting Lyme disease:
- Whenever possible, avoid thick brush and high grass.
- Tuck your pant legs into socks or gaiters. Once a tick finds you, its instinct is to move upward on your clothing until it finds an entry point to your skin. Tall rubber boots, 16 inches or more, are too smooth for ticks to climb and can be an effective deterrent.
- To discourage ticks from attaching to you, apply repellents to socks and pants, especially to lower pant legs. Remember, many ticks hang out from 0 to 4 inches above the ground. DEET is the most effective repellent; however, some people are sensitive to it. DEET should never be used on infants. Permethrin is a clothing spray that repels and/or kills ticks. Permethrin is quite effective and clings well to cotton. After applying, let it dry thoroughly before wearing the clothing. Permethrin should never be applied directly to skin. Permethrin will survive multiple launderings. Picaridin works well on mosquitoes and is almost as effective as DEET on ticks. For those who are sensitive to DEET, Picaridin is a good alternative. IR3535 also works well. At this time, there is no human vaccine for Lyme disease, but there may be some vaccines in the pipeline.
- Examine and monitor for ticks after every day you work outdoors in areas ticks might inhabit. Of all the techniques for reducing your odds of getting Lyme disease, monitoring and examination are the most important. Strip and check (or have someone check for you) your entire body, including hair. For self-examination, use a full-length mirror and a bright light. Ticks particularly like the waistband area. Be especially vigilant in May, June, July and October. (August may be too warm and dry for ticks.)
- Segregate your clothin
g. Since ticks are killed by warm, dry conditions, clothing placed in a hot dryer for five minutes will be tick-free. Microwaving clothing (in a plastic bag) will also work.
- Remove ticks promptly. Since tick bites are painless, ticks often go unnoticed until after they’ve begun to feed. Remove a tick by grasping it as close to the head as possible using a forceps or tweezers. Pull outward using slow, steady pressure. Do not yank or pull sideways, as this could cause the head to break off. A notched tick spoon (one brand is Ticked Off) also works well to pry out ticks. Do not use a hot match or Vaseline. When a tick bites, it secretes a kind of cement to help it hold on. This cement prevents it from backing out even if it were inclined to. The tick also injects saliva to keep its blood meal from clotting.
- Record date, time and location of any suspected tick bite. If you discover a suspect rash a week, month or more after you were bitten, you have accurate data to help yourself and your doctor diagnose and treat your illness.
Managing ticks on your property
While there may be areas of your farm where the most effective option for avoiding disease-carrying ticks is monitoring yourself, there are some land management techniques that can help. Because dry conditions are the greatest natural mortality factor for ticks, it’s useful to limit wet areas. In addition, try to reduce human contact with wet areas and with tall grass or thick brush. Consider the following land management techniques where feasible:
- Manage land to avoid herbaceous vegetation or thick brush.
- Fence out areas with thick brush and tall grass, especially areas where people and companion animals might travel.
- Widen trails and paths, keeping them free of vegetation, thus limiting tick habitat.
- Be informed. Know your risks, and use signs, fact sheets or workshops to keep your employees, your family and others safe.
- Keep play equipment and recreational activities away from the edge of woods.
- Apply pesticides, especially in early June. “One proper treatment should greatly lower the number of blacklegged tick nymphs. Adults are harder to kill, but susceptible,” Eaton said. Target leaf litter and the lower 18 inches of shrubs. “A thorough pressure application which disturbs leaf litter is most effective,” Eaton added. “Green” sprays, such as EcoEXEMPT IC2, can be effective; pyrethrins and piperonyl butoxide (PBO) have limited efficacy.
- Control ticks on small mammals by aiming control chemicals (where appropriate) at them. One such method involves the use of “tick tubes,” cardboard tubes filled with pesticide-treated (permethrin) cotton. Tubes are placed where mice and chipmunks will find them and take the cotton as nesting material. Attached ticks are carried back to nests, where the treated nesting material causes the ticks to drop off and die.
Remember Eaton’s warning: “If you don’t think about ticks, you are the perfect victim. But you do have the ability to greatly increase or greatly decrease your risk of getting tick-borne diseases.”