The deer tick (Isodes scapularis) also known as the black-legged
tick is found throughout the Northeast, Southeast, Midwest, and some
areas of the Southwest. Deer ticks are the primary vector for a variety
of diseases including Lyme disease, babesiosis, and ehrlichiosis. Over
the past 10 years over 100,000 cases of disease caused by deer ticks
have been reported. Deer tick populations continue to increase and as
their populations grow so does the risk of contracting a tick-borne
disease. As a consequence, there is an increased demand for pest
managers to develop and implement effective deer tick control programs
in both residential and recreational areas.
Deer ticks are parasites and must feed on blood to survive and
reproduce. They begin their life as tiny eggs, which hatch into
sexually immature larvae about the size of a grain of sand. The mobile
stages of this pest climb onto foliage or structures like fences or
buildings waiting for potential hosts to wander by. The larval ticks
infest small animals, such as mice or birds, for several days, taking
in blood until they are engorged and drop off the host, usually into
leaf litter or thatch. The engorged larvae molt into sexually immature,
eight-legged nymphs, which are about the size of a poppy seed. These
nymphs then take a blood meal, usually on a small to medium sized
mammal such as a squirrel or rabbit, feeding for four or five days. The
engorged nymphs drop off the host and eventually molt into a sexually
mature eight-legged adult. The adults latch onto a large mammal such as
a deer where they mate where the females subsequently attach and feed
for about a week. They then drop off and lay eggs. This whole process
can take two years with peak activity occurring in different seasons.
From a public health perspective, it is most important to control the
nymphal tick because 90% of all Lyme disease cases are due to bites
from this life stage.