Blacklegged Tick (Female)

Description:

If you've ever wondered what the ventral side of a tick looks like, check out photos 2 and 3! On the underside, the upper, central opening between the fourth pair of legs is called the genital aperture. The lower central opening is the anus. The two whitish circular openings underneath the fourth legs are the spiracular plates. The genital aperture and anus are fairly self-explanatory due to their names. The spiracular plates contain spiracles through which the ticks breathe. Interestingly, larval ticks do not have spiracular plates, but rather they breathe through their skin. Nymphal and adult ticks do have spiracular plates, and they are able to control the opening/closing of their spiracles using muscles and hemolymph (blood) pressure. Ticks have a very delicate balance to maintain between their need to open their spiracles to breathe, but not have them open long enough to desiccate. Luckily for them, they can close their spiracles for long periods of time and survive without any oxygen exchange. This tick is an adult, female blacklegged tick. They have black heads and dorsal shields, dark red abdomens, and 8 legs.

Habitat:

This is the third tick I found crawling on me while hiking in a deciduous forest. The temperatures were only in the low 40's Fahrenheit (6 Celsius), and I was surprised to find active, blood-seeking ticks. Of the three ticks, two were adult females, and one was a nymph - which unfortunately had attached and started feeding before I found it.

Notes:

The lifecycle of blacklegged ticks generally lasts two years. During this time, they go through four life stages: egg, six-legged larva, eight-legged nymph, and eight-legged adult. Ixodes scapularis is a three-host tick, which means that it must have one bloodmeal during each life stage (larva, nymph, adult) in order to survive. Ixodes scapularis is the main vector of Lyme disease in North America. It can also transmit other diseases such as Babesiosis, Powassan, and Anaplasmosis.