Know Your Vector: American Dog Ticks

- [Narrator] Dermacentor variabilis, more commonly known as the American Dog Tick can be found throughout Eastern North America including all of Pennsylvania.

This tick species can transmit pathogens that cause diseases such as Rocky Mountain spotted fever and tularemia.

You are most likely to encounter an American Dog Tick during their peak activity in the summer.

However, because they can live for extended periods of time without feeding, you could encounter them at any point in the year as long as it is warm enough for them to be active.

Ticks require a blood meal from a host to progress into the next life stage from larva to nymph, to adult, and finally to egg production.

American Dog Tick larvae and nymphs preferentially feed on small and medium sized mammals, such as mice, rabbits, skunks, and raccoons.

At this life stage they rarely bite humans.

The adults on the other hand preferentially feed on large mammals like humans but especially canonists such as coyotes, foxes, and dogs.

American Dog Ticks are distinctive among cakes that bite humans and pets due to their ornate color pattern of dark red and white reticulations, the interlacing lines resembling a net.

This pattern is restricted to the scutum, the hard shield on the dorsal or back surface of the tick.

On males the scutum covers most of the dorsal surfaces.

So this pattern is more apparent than it is in females.

Females that are engorged, that is those that have obtained a blood meal from a host can measure up to 15 millimeters in length.

However, the scutum and patterning are still apparent and can be used to identify them.

Another defining characteristic of American Dog Ticks is the ridges on the edge of their lower abdomen, known as festoons.

The festoons in conjunction with the unique color pattern make this tick easy to identify.

In summary, American Dog Ticks can be found throughout Eastern North America and are active during the spring and summer, but can continue to be active into the fall or on mild winter days.

These ticks can be identified by the distinctive dark red color with white markings on the scutum.

They also have festoons around the edge of their abdomen.

The larvae and nymphs of this species feed on small mammals like mice, rabbits, and skunks, while the adults feed on larger mammals, such as coyotes dogs and humans, if they get the chance.