Blacklegged
tick
Common
Name:Blacklegged
tick / deer tick
Scientific Name: Ixodes scapularis
Introduction. The
common name blacklegged
tick refers to their
dark legs which are
in contrast to the paler
body and that of deer
tick because the preferred
adult host is the white
tailed deer. This tick
is of medical importance
because it is an important
vector of Lyme disease.
Blacklegged ticks are
found primarily in the
Northeastern, Midwestern
and southeastern states
in the United States,
but extend into Mexico.
In Ohio it is most common
in the outermost counties.
Recognition. The unengorged female
tick is about 1/8 inch
long, while the male
is smaller about 1/16
inch long. The flat
oval body is colored
orange-brown to reddish-brown
and the legs are dark
reddish-brown to black
in color.
Biology. Although the life cycle
(egg to egg) can be
completed in 2 years
in nature, it may be
extended to 4 years
if hosts are scarce.
Adult ticks feed during
the winter primarily
on the white tailed
deer. Here they mate,
with the male dying
shortly after mating
and the female remaining
on the host. In the
spring, the female drops
off the host and deposits
about 3,000 eggs. The
6-legged larvae hatch
out in several weeks
(48 to 135 days) and
can be found June through
September. They feed
for 3 to 9 days but
only once, usually on
small mammals such as mice, chipmunks, voles,
etc.; but the preferred
larval host is the white
footed mouse and deer
mouse. Larvae feed before
September, molt promptly
and overwinter as 8-legged
nymphs; those which
feed later, overwinter
engorged and molt into
nymphs the following
spring. Nymphs feed
for 3 to 8 days but
only once during the
summer, usually on mice
or larger mammals such
as squirrels, raccoons,
opossums, skunks, dogs,
and humans, or on birds.
Nymphs can be found
from April through August,
with the population
usually peaking in June
or July. These fed nymphs
then require 25 to 56 days to molt into adults
in the autumn. The adults attach primarily to
the white-tailed deer,
engorge and mate.
The
male dies after mating
but the female continues
to feed until egg development
is completed and remains
on the deer until spring
when she drops off to
lay eggs. Shortly after
her eggs are laid, the
female dies.
If adults do not feed
during their first season
(summer), most die off
but they can survive
through 2 seasons (May
through August of the
next year); they develop
into adults in the same
year in which they feed.
Unfed larvae survive
less than one year,
they usually survive
the winter but die during
the following year.
Lyme disease is caused
by the spirochete, Borrelia
burgdorferi which is
a corkscrew-shaped bacteria.
Its primary wild reservoirs
are the white-footed
mouse and deer mouse
which are infected by
the spring-feeding,
pathogen-infected blacklegged
/ deer tick nymphs.
These mice then serve
to infest the later
feeding blacklegged/deer
tick larvae, which perpetuates
the disease cycle.
Tick eggs don’t contain
the spirochetes; they
are acquired via feeding.
It is the pathogen-infected
blacklegged/deer tick
nymphs, which are most
active in mid-summer
(May-July) and use a
wide variety of hosts,
that are primarily responsible
for Lyme disease in
humans in the northeast
and Midwest. Larvae
and nymphs have been
collected on 29 species
of mammals in 7 orders,
and from 49 species
of birds (23 species
being migratory birds)
in 17 different families.
Habits. Blacklegged / deer ticks
climb the grass and
shrubs to wait for a
passing host, and move
very laterally. They
concentrate on such
vegetation located in
transitional zones such
as where forest meets
field, mowed lawn meets
unmowed fence line,
borders of foot paths
and animal trails through
high grass or forest,
etc. Because these transitional
areas or edge habitats
are where most animals
travel sometime each
24-hour period, this
is where the ticks are
most likely to acquire
a host.
The other habitats most
likely to harbor ticks
are the dens, nests
or burrows of host animals,
such as skunks, raccoons,
opossums, and especially
white-footed and deer
mice. These brown and
white mice prefer woody
or brushy areas. They
nest below ground, beneath
logs, wood debris and
woodpiles, in stumps,
old nests of birds and
squirrels, and in undisturbed
areas of buildings.
A favorable feeding
area for these ticks
on humans is at the
back of the neck, at
the base of the skull;
long hair makes detection
more difficult. However,
the ticks will usually
wander for about 4 hours
or so before they attach.
Then, a tick has to
be attached for a period
of 6 to 8 hours before
a successful transmission
of the Lyme disease
pathogen can take place.
Control. The reduction of these
ticks is a multi-step
process. The first 2
steps are sanitation
and personal protection,
which are the responsibility
of the homeowner or
occupant(s):
Cultural
Control & Preventative
Measures
1. Sanitation, consists
of the following: (a)
keep grass cut low including
around fence lines,
sheds, trees, shrubs,
swing sets and other
difficult to cut locations;
(b) remove weeds, woodpiles
and other debris which
are attractive to mice
as nesting sites, and
leaf litter which is
attractive to ticks,
especially the nymphs;
(c) keep garbage can
lids on tight to discourage
opossums, raccoons and
skunks from coming into
the yard to raid garbage
cans for food because
these animals all harbor
the ticks which transmit
the Lyme disease pathogen;
(d) discourage messy
methods of feeding birds
because seed on the
ground attract deer
mice, the major reservoir
host of the Lyme disease
pathogen; and (e) install
chimney and attic vent
screening to keep squirrels,
raccoons and birds out
of the house.
2. Personal protection
consists of: (a) insect
repellents that contain
deet or permethrin;
(b) tucking pants into
socks or boots when
going into suspect areas;
(c) checking children
for ticks when they
come into the house
because it takes about
4 hours for the tick
to start feeding; (d)
wearing light colored
clothing which makes
spotting ticks easier;
(e) carefully examining
pets which go outdoors
because they may increase
the chances of blacklegged
tick exposure; especially
cats; and (f) having
a veterinarian perform
a blood test on pets
that go outdoors to determine if they are
carrying the Lyme disease
spirochete.
Professional
Control.
1. A Rottler technician
will treat the exterior
perimeter of the structure
or the entire property
with an appropriately
labeled residual pesticide
if ticks are present.
2. The technician may
perform an exterior
perimeter rodent control
program to reduce the
host populations for
this tick.
Lyme
disease. The
symptoms are usually
divided into 3 stages,
and they mimic several
commonly occurring diseases.
Symptoms: Spreading
rash, fever, flu-like
symptoms and aches
Stage
1: expanding
rash (erythema migrans
or EM rashes) occurs
3 to 30 days after the
tick bite.
• Ringlike or bullseye
appearance to rash
• One or more rash sites
• May or may not have
flu-like symptoms
• May come and go or
persist
Stage
2: Complications
or disorders of the
heart or nervous system
• Heart. Varying degrees
of blockage of the heart
muscle.
• Nervous system. Meningitis,
encephalitis, facial
paralysis
• “Bell’s palsy” and
other conditions involving
peripheral nerves.
• Migratory pain in
joints, tendons, muscles,
and bones, often without
joint swelling or redness.
Stage
3: Months to
years after disease
onset.
• Arthritis that appears
and disappears intermittently
for several years.
• Enlarged knee joints.
• Erosion of cartilage
and bone.
Medical treatment
notes:
1. Once bitten
by a blacklegged / deer
tick that possesses
the spirochete, antibodies
may not be produced
in the victim for up
to 6 weeks. Therefore,
it takes time to verify
that one has Lyme disease.
2. Oral medications
for Lyme disease can
destroy the spirochetes
in the blood and give
an antibody reading
that the person is “cured”.
However, the spirochete
may persist in the brain
and reappear in the
person 5 to 10 years
later. Therefore, intravenous
treatment is advised
over oral medications
by some physicians considered
experts in this area,
especially for persons
showing stage 2 or stage
3 symptoms.
Tick
removal:
1. The best way to remove
a tick found attached
to a person or pet is
to
firmly grasp it with
a pair of fine-tip tweezers
as close to the skin
as
possible.
2. Pull firmly but gently
backwards until the
tick pulls free.
3. Do not touch the
tick, but save it in
rubbing alcohol for
later
identification.
Locations
Serving the St. Louis Metropolitan area since 1956, including
Arnold, Ballwin, Chesterfield, Crestwood, Creve Coeur, Des Peres,
Fenton, Florissant, Kirkwood, Maryland Heights, Overland, St.
Charles, Webster Groves, Wentzville and surrounding areas.
In Illinois: Belleville, Collinsville, Edwardsville, Columbia,
Madison, Waterloo, O’Fallon, Granite City, Alton, St. Clair, Monroe
and surrounding areas.
Columbia & Jefferson City, MO and surrounding areas.
