Des Moines Register
06-02-07
Ticks as small as head of pin lurk in woods
By MARY CHALLENDER
REGISTER STAFF WRITER
Is your scalp crawling?
If not, you probably haven't spent much time outdoors in Iowa recently.
Spring rains and warmer weather have produced a bumper crop of something
Iowans could do without - ticks.
"We seem to be seeing more ticks than normal and they seem to be starting
earlier than normal," said Angelic Vetter, a veterinarian at All Creatures Small
Animal Hospital in Indianola.
"We're seeing both dogs and outdoor cats coming in for normal exams that do
have ticks on them."
Ken Holscher, an associate professor in the entomology department at
Iowa State University, said every year about this time, he gets calls from people
asking, "Is this the worst tick season on record?"
His answer: No one is really out there counting from year to year.
Holscher's view is the more often that nice weather lures people into the woods
for fishing, mushroom hunting and nature hikes, the more ticks make their
presence noticed.
"People find ticks, ticks don't find people," he said. "And if you have a dog, dogs
are like biological vacuum sweepers. They're going to find them."
Although there are far more varieties of ticks in Iowa than most people care to
know, Holscher said there are only a few that Iowans really need to be aware of.
The most common is the American dog tick, the eight-legged brown creature
about the size of a match head referred to by many people as a wood tick.
In southern Iowa, the Lone Star tick - similar in size and coloring to the dog tick
except females have a white "star" on their backs - can also be found in
abundance, Holscher said.
Black-legged ticks, better known as deer ticks, are more of a reddish-brown and
about the size of a pinhead. They are most common in the northeastern quadrant
of the state.
Deer ticks can transmit a serious bacterial infection called Lyme disease, while a
much milder rash-related illness has been associated with the Lone Star tick.
Because it can be hard to tell an adult deer tick from immature stages of the
other two varieties, Holscher said, the smart thing is to keep ticks from biting you
if possible.
To survive, ticks have to live in an area where the humidity is 75 percent or
above, Holscher said. That's why they are so common in tall grass and wooded,
shady areas and scarce in closely mowed, treeless, suburban lawns.
Ticks live on ground
Contrary to accepted wisdom, ticks do not live in trees and they do not drop on
your head as you walk by, Holscher said.
"If you have a tick attached to the top of your head, it started at your legs and
crawled all the way up until it got to that point," he said.
Ticks live on the ground, moving as little as possible to conserve energy as they
wait for a host to pass. Anything that contains blood is an acceptable meal,
Holscher said, even cold-blooded creatures like reptiles.
Although some ticks have eyes, their vision is limited to tell between light and
dark, he said. The blood-sucking insects depend on vibrations and scents like
carbon dioxide to detect a host.
When a tick senses a host is near, Holscher said, it crawls to the top of a blade of
grass and hangs there, hoping the animal or human brushes against it as it walks
by.
If it doesn't, after awhile the disappointed tick will drop back to ground level and
wait for a new host. Holscher said as long as the humidity is adequate, ticks can
survive without a meal for months.
The only way to avoid ticks is to stay out of their habitat, Holscher said. Mosquito
repellents, even the kind with higher concentrations of DEET, he said, don't work
well against ticks.
The repellent Permanone is effective, he said, but you may have to go to a
specialty sporting goods store to find it.
As a student in Oklahoma working on tick research, Holscher said, he found
dressing appropriately was his best defense. He suggests long pants, long socks
and lace-up boots or tennis shoes.
"Stick your pant leg into your boots or socks," he suggested. "The other thing we
used to do is we wrapped masking tape around our pants legs where they were
stuck in the boot then twisted it so the sticky side was out. It looks a little weird
but as ticks crawl across the tape, they get stuck."
Unappealing prospect
It usually takes ticks about a day to work their mouth parts under the skin and
begin feeding, he said, an unappealing prospect even in the absence of Lyme
disease.
"Ticks do regurgitative feeding," Holscher said. "The female tick inserts her
mouth parts, sucks in some blood but she only wants the red blood cells so she'll
spit the rest back in. That's why if you take a tick off you and smash it, you don't
get bright red blood, you get a thick chocolate-looking blood. It's packed with red
blood cells."
To remove ticks attached to the skin, Holscher suggests grabbing them near the
mouth parts with a pointed pair of tweezers. Regardless of what your mother may
have told you, whether or not you get the entire head isn't really that important,
he said.
"I don't know why people go nuts over that," Holscher said. "Even if you snap the
mouth parts off, they're not going to do anything. It's just like a splinter under the
skin."
Once the tick is removed, Holscher generally sticks it to masking tape, wads the
tape in a ball and puts it in the trash.
If you're concerned it could be a deer tick, stick it to the masking tape and then
put it in the freezer. That way, he said, if you develop a "bull's-eye" rash or flu early symptoms of Lyme disease - you can always take the tick in and get it
typed.
Reporter Mary Challender can be reached at (515) 284-8470 or
mchallender@dmreg.com