The Black Legged Tick, formerly known as the deer tick, is the main vector in the spread of Lyme Disease.  Lyme disease is a disabling and difficult to treat problem effecting millions of people and pets in the North East.  The Black Legged tick has a 3 host life cycle that includes small rodents and larger animals.  The multiple hosts give the ticks 3 chances to pick up the bacterium that causes Lyme disease, while the ticks themselves are not effected. Vectors are animals that spread disease, while reservoirs are animals that harbor disease organisms.  Common reservoirs for Lyme disease are the White Footed Mouse, Voles, Shrews, Chipmunks, Squirrels, and the White Tailed Deer.

After mating on the host animal, likely a White Tailed Deer, the females drop off in the Spring to lay eggs in the leaf litter.  The egg mass, often containing thousands of eggs, hatches releasing a horde of hungry larval ticks.  The tiny six legged larval ticks are sensitive to sunlight and desiccation, keeping low to the ground where they find the first of three hosts.  After feeding the larval ticks drop off, and molt into the nymph stage.   The tiny nymphs, or seed ticks have eight legs like the adult, but are still sensitive to light and desiccation.  The nymphs  also seek smaller hosts that live in the leaf litter and concealed locations like rock walls and thick ground cover. Once the nymphs feed they drop off the host and molt into the adult ticks.  Adult Black Legged ticks have harder bodies than the immature stages and climb up onto shrubs and grasses to find their larger animal hosts like White Tailed deer.  After overwintering on the host, the females drop off to begin the cycle again.  The entire life cycle of  Black Legged tick can take up to 2 years.

Tim Chace
Colonial Pest Control Inc.

Photo Credit : By Content Provider(s) : CDC/ Michael L. Levin, Ph. D. Photo Credit : Jim Gathany – http://phil.cdc.gov/phil/detail.asp?id=1669Transferred from fr.wikipedia to Commons., Public Domain, Link