Tick Facts
Ticks
are arthropods that are sometimes
mistakenly called insects. Insects have
three body regions, six legs, and
typically possess wings. Ticks lack
wings, have two body regions, and
depending upon their developmental
stage, may have either six or eight
legs. Ticks possess tremendous potential
for transmitting organisms that may
cause disease in humans and other
animals. These disease-causing organisms
include protozoa, viruses, and bacteria.
Bites from certain ticks can cause a
rare limp paralysis starting in the
lower limbs and moving upwards with
death resulting if the tick is not
promptly removed. Additionally, tick
bites can cause skin irritations or even
allergic reactions in sensitive people
who are repeatedly bitten.
Ticks
undergo four developmental stages: egg,
larva, nymph, and adult. Nymphs and
adults have four pairs of legs, while
larvae have three pairs. All
developmental stages of ticks are
obligate blood feeders. They must obtain
a blood meal to molt to the next life
stage and for female ticks to develop
eggs. Males remain on their host and
mate with several females; they too will
eventually drop from their host.
Depending upon the species of
tick, the number of eggs laid may range
from a few hundred to several thousand.
In most cases, the larger the volume of
blood taken, the more eggs the female
will be able to produce. The egg-laying
process may take from several days to
two or three weeks to complete. The
female dies shortly after laying her
eggs. The developmental period for each
tick stage varies, and the entire life
cycle may take up to two years or more
to complete.
Ticks do not jump or fly and must
literally come in contact with a host.
Favorite vegetation sites for adult
ticks that quest include tall grass and
shrubs. Immature ticks are more likely
to remain near the leaf litter or lower
in the vegetation where they are more
likely to encounter small rodents and
ground-visiting birds.
Protect
your health. Protect your family.
With
a Healthy Home Tick Service from Pestech
®,
you'll know you're protected.
To schedule,
click here or call us
Monday- Saturday, 8am-5pm at
1-800-287-2847.
**
Contact us before April 15th, 2008 to receive exclusive
internet pricing! Time is ticking............. **
Tick
Species in New York State
New
York state has several species of ticks.
Those of greatest public health
importance are the American dog tick,
the brown dog tick, the lone star tick,
the groundhog tick, and the blacklegged
tick.
American
Dog Tick (Dermacentor variabilis)
The American Dog Tick, Dermacentor variabilis.
Clockwise: nymph, larva, male, female.
American dog tick females are
about 1/4 inch (6.35mm) long and are chestnut brown with a silvery-gray or
creamy-white scutum. Male ticks are slightly smaller, and are chestnut brown
with similar light-colored vertical markings on the dorsal surface. Larvae feed
on small mammals, and nymphs feed on small-to medium-sized mammals. Adults,
sometimes called wood ticks, occasionally attack humans but are more common on
dogs and other medium-sized animals.
Dermacentor variabilis is
a known vector of Rickettsia rickettsii, a bacterium that causes Rocky
Mountain spotted fever in humans. Most Rocky Mountain spotted fever cases are
reported from the south Atlantic and south central states, but cases do occur
each year in New York state, especially on Long Island. The average incubation
period after an infected tick bite is seven days and results in fever, severe
headache, and joint and body aches. Within a few days a spotted rash appears on
the wrists and ankles and spreads to the palms, soles, and eventually to the
rest of the body. Rocky Mountain spotted fever is treatable with antibiotics
but can be fatal if not treated promptly. Rickettsia rickettsii can be
transmitted to eggs. Consequently unfed larvae are capable of transmission, in
addition to nymphs and adults.
Brown Dog Tick (Rhipicephalus
sanguineus)
The
Brown Dog Tick, Rhipicephalus
sanguineus. Starting with the upper
left and going clockwise: fully
blood-engorged female, female, larva,
male.
Brown
dog ticks are reddish-brown with a dark
brown scutum. Unfed females are about
3/16 inch (4.76mm) long. All stages feed
almost exclusively on dogs and can
become established in kennels. Although
brown dog ticks can be found crawling on
humans they rarely attach and feed on
humans. This tick is considered a
nuisance species and is not known to
transmit disease-causing organisms to
humans in the United States.
Lone Star Tick
(Amblyomma americanum)
The Lone Star Tick, Amblyomma americanum.
Clockwise from upper left: nymph, male, female.
All stages of Amblyomma
americanum will aggressively attack people and other medium-to-large
mammals. Females are 1/4 inch (6.35mm) long and reddish brown in coloration. A
distinctive white spot or "star" on the scutum is characteristic of
females. A reticulated pattern is apparent on the outer margins on the upper
body surface of males. Lone star ticks have long mouthparts but with care the
stylets can be completely removed from the host skin. Even with successful
removal of mouthparts the cementing substance is left in the bite wound. This
cement material can causing itching, skin irritation, and localized swelling
immediately around the bite. Please refer to the guidelines for safe tick
removal in this fact sheet.
Several cases of human monocytic
ehrlichiosis are reported annually in New York State with most cases
reported from Long Island and the lower Hudson River Valley. The causative
agent is Ehrlichia chaffeensis, a type of bacterium. After an incubation
period of 5 to 10 days nonspecific symptoms appear, including a high fever,
severe headache, chills, aching muscles and joints, and fatigue. Patients may
exhibit a rash, but it is not a common clinical feature of the disease. Usually
infection with Ehrlichia chaffeensis is mild, but severe manifestations
of the disease may result in death. Human monocytic ehrlichiosis is
treatable with antibiotics.
Ixodes cookei (Ixodes
cookei)
Ixodes cookei. Clockwise from upper left: female,
nymph, larva.
Ixodes cookei
has no official common name but it has been called the groundhog, woodchuck, or
carnivore tick. Groundhog ticks are very similar in appearance to blacklegged
ticks (Ixodes scapularis), thus microscope examination is required to
properly distinguish between these two species. Ixodes cookei has been
found to parasitize a wide variety of carnivores and rodents but can be
especially abundant on groundhogs (Marmota monax). The groundhog tick
rarely quests for hosts on vegetation. Rather, they are found in the burrow of
their host. This tick is primarily considered a nuisance, but it has been
associated with the transmission of a virus that causes Powassan encephalitis.
Powassan encephalitis is rare, and just a handful of cases have been reported
in New York state since its discovery in North America in 1954. This is
probably a reflection of the low contact rate between humans and infected
vectors. Infection with Powassan virus can cause inflammation of the brain
(encephalitis) and sometimes meningitis.
Blacklegged Tick or Deer
Tick (Ixodes scapularis)
The
Blacklegged Tick, Ixodes scapularis. From left to right: female, nymph,
male.
The blacklegged tick is the
officially accepted common name for Ixodes scapularis, but many people
refer to them as "deer ticks". Adult females are dark brown in
appearance and are less than 1/8 inch (3.12mm) long. Larvae and nymphs feed on
small mammals and birds. The white-footed mouse is an important host for the
immature ticks, while adults are more common on deer. All stages will bite
humans, but due to their small size, attachment by larvae and nymphs often goes
unnoticed.
The blacklegged tick is a vector
of two bacterial diseases and one protozoan disease in New York state. Lyme
disease is caused by infection with the bacterial spirochete Borrelia
burgdorferi. Nymphs are considered to be the most important stage for
transmission because they are easily overlooked due to their small size. Signs
and symptoms of Lyme disease usually appear within 1 to 2 weeks (range 3-30
days) following an infected bite. In addition to flu-like symptoms roughly
sixty to eighty percent of infected people develop a spreading rash (erythema
migrans). The rash slowly spread and has a distinctive bulls-eye appearance.
The risk of contracting an infection from a tick is virtually nil during the
first 24 hours of attachment, so promptly removing ticks can reduce your
chances of contracting Lyme disease. Untreated cases may resolve or progress to
chronic joint, neurological, or cardiac problems. Lyme disease is treatable
with antibiotics. Serological tests are used to support the clinical diagnosis
of Lyme disease. These tests are designed to detect antibodies against Borrelia
burgdorferi. The reason that serological tests are not performed until
several weeks after the appearance of symptoms is because it takes time for the
immune system to develop detectable antibodies. Most cases of Lyme disease are
reported from Long Island and the lower Hudson River Valley.
Excerpt from:
