Deborah
Smith-Fiola
Rutgers Cooperative Extension
Lyme
disease is spread by the tiny deer tick. Ticks feed on blood,
and infected ticks transmit the disease as they feed. Although
the deer tick prefers to feed on wild animals, especially
mice, birds, opossum, raccoon, and deer, they will also feed
on dogs, cats, livestock, and humans. When people visit or
live near deer tick habitats, they run a high risk of contracting
Lyme disease. For your own safety, you should become familiar
with tick habits and habitats, and you should learn how to
prevent tick bites.
Deer ticks prefer to live in the woods. Dense, mature woods
with a thick undergrowth of shrubs and small trees are their
favorite habitat (85%). They also are found, to a lesser degree,
along the edge of the woods, where the woods meet lawns or
fields. Very few (4--8%) are found in lawns, because properly
mowed lawns are too hot and dry to sustain the tiny deer tick.
Ticks prefer the cool, moist woodlands where they have a better
chance of finding an animal host.
Where
you live, your hobbies, and your habits may influence your
risk of a tick bite. Notice in particular these high-risk
factors:
- yards
surrounded by dense woods
- birdbaths,
birdfeeders
- outdoor
pets that come indoors
- woodpiles,
brushpiles, stone or rock walls
- swingsets,
treehouses in the woods
- outdoor
occupations: landscapers, utility line workers, farmers,
etc.
- outdoor
recreation: freshwater fishing, camping, hiking, hunting,
etc.
Many
of these factors encourage wildlife near the home, and these
animals may carry ticks. Mice in particular are known hosts
of immature deer ticks and carriers of Lyme disease. Reduce,
remove, or avoid these risk factors as much as possible.
Outdoor
pursuits need not be discontinued as long as precautions are
taken to prevent a tick bite:
- Wear
light-colored clothing (ticks are easier to see).
- Wear
long pants tucked into socks.
- Avoid
tall grass and shrubby areas.
- Widen
trails through woods (to 6 feet).
- Remove
brushpiles.
- Keep
turfgrass mowed.
- Thin
out low shrub vegetation in woods.
- Wear
a tick repellent.
Repellents
contain the active ingredient permethrin (Duranon, Permethrin
Tick Repellent, Permanone), or N,N-diethyl-meta-tolumide,
usually called DEET (Off, Cutters, Muskol, etc.)* Follow label
directions; apply until clothing is damp and allow to dry.
These products repel 82-100% of ticks.
Seventy
percent of all Lyme disease cases occur from the bite of the
immature (nymph) deer tick. Before feeding, nymphs are the
size of a poppy seed with a dark head and translucent body.
After feeding, they swell and appear dark gray and round,
about the size of a mustard seed.
Adult
deer ticks are the size of a sesame seed before feeding; females
have a black head and brick red abdomen. After feeding, they
turn gray and swell to the size of a sunflower seed kernel.
Deer
ticks are active all year round, as long as the temperature
is over 35°F. Peak activity months are May-June (nymphs),
and October-November (adults).
Ask
your county extension agent for a free copy of the bulletin
"Protect Yourself from Ticks
and Lyme Disease" for specific ways to identify different
ticks. The Lone Star tick may have a slight involvement in
Lyme disease transmission; the American dog tick is not known
to be involved in Lyme disease transmission in New Jersey.
Ticks don't fly, jump, or drop from trees. They inhabit shrubby
vegetation (nymphs: four- to six-inch vegetation; adults:
waist-high vegetation) and wait for an animal to brush by.
They then grasp the animal's fur or skin, and crawl up the
body. Ticks will wander on the body for 30-60 minutes before
they insert their mouth-parts and begin to feed.
INFECTED
DEER TICKS MUST FEED FOR AT LEAST 12 TO 24 HOURS before they
can begin to transmit the Lyme disease bacterium. Therefore
you should remove ticks as soon as possible. Take a shower
after outdoor activity and check your body thoroughly, paying
close attention to the armpits, the groin, and neck. Use the
buddy system! Look for ticks nightly, especially if you have
young children.
In New
Jersey, approximately 20 to 40 percent of deer ticks are infected
and able to transmit Lyme disease. The infection rate is linked
with native white-footed mouse populations.
Remove
ticks with tweezers only (bent, "needle-nose" tweezers are
best). Do not use alcohol, nail polish, hot matches, petroleum
jelly, or other methods to remove ticks. These methods may
actually traumatize ticks, causing them to regurgitate gut
contents, which may include the Lyme disease bacterium.
If avoiding
tick-infested areas is not possible, pesticide use may be
justified. Research has shown that granular insecticides may
provide longer lasting controls than liquid sprays. READ AND
FOLLOW ALL DIRECTIONS ON THE LABEL. Some insecticides authorized
for tick control include:
- SEVIN
(carbaryl)
- PERMETHRIN
(a pyrethroid)
- DURSBAN
(chlorpyrifos)
- DIAZINON
(spectracide)
Granular
insecticides should be applied once a year in low-risk areas
(late May) and twice in high-risk sites (late May and late
June). An early October adult treatment is optional. Focus
treatment along the edge of the woods and 15 feet into the
woods. These treatments have resulted in more than 90 percent
control in research trials.
Liquid
insecticides should be thoroughly sprayed on vegetation until
they run off. Apply in mid-May, early June, and (optional)
late June. Sprays targeting adult deer ticks may be applied
after leaves have dropped from the trees, from November to
April.
DAMMINIX
is a product that provides insecticide-laced nesting material
to mice. It kills immature ticks feeding on mice in their
burrows. Place it only in areas where mice frequent. Damminix
may also be used in combination with the above insecticides.
For
more information on Lyme disease, see your health care provider.
Disclaimer
and Reproduction Information: Information in NASD does not represent
NIOSH policy. Information included in NASD appears by permission
of the author and/or copyright holder. More
NASD Review: 04/2002
Deborah
Smith-Fiola - County Agricultural Agent, Ocean County
This
publication was made possible in part by a grant from the
National Institute for Occupational Safety and Health Program
on Agricultural Health Promotion Systems for New Jersey.
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