Know Your Vector: Blacklegged Ticks

- [Narrator] Blacklegged ticks are some of, if not the most commonly encountered ticks in Pennsylvania and most of the Northeast.

Although they're commonly referred to as Deer ticks, these ticks utilize many other types of hosts other than deer.

Blacklegged ticks also known as Ixodes Scapularis are found throughout Eastern North America.

These ticks are still expanding westward.

Blacklegged ticks are less common and abundant than other species in the south.

However, they're still present there.

On the West Coast you can find a similar species, the Western blacklegged tick, Ixodes Pacificus.

Blacklegged tick females lay eggs in the Spring.

These eggs hatch and the six legged larvae feed on birds and small mammals such as mice and chipmunks.

Pathogen causing bacteria and viruses are not passed from mother to offspring.

Larval blacklegged ticks usually feed on only one host and they rarely bite humans.

The fed larvae over Winter and molt into nymphs in the Spring.

The nymphs feed on small mammals such as mice and medium and large mammals including humans.

If the nymph bit a host infected with a pathogen is a larva, it may transmit that pathogen to a human.

While a higher percentage of adult ticks test positive for pathogens, the risk of pathogen transmission from nymphs is often greater because they're smaller and harder to detect compared to adult ticks.

Fed nymph full blacklegged takes molt into adults in the Fall.

Adult ticks feed on medium and large mammals including humans and especially deer.

If the tick acquired pathogens as a larva nymph, it may transmit them to hosts when feeding.

Adult blacklegged ticks are active throughout the Winter as long as it is above freezing.

This may include sunny days when the air temperature is near or below freezing but individual spots of leaf lit warm by the sun are warmer.

Blacklegged ticks are generally less active when a uniform blanket of snow is present but can still sometimes be found if the snow falls quickly after a warm day or when snow is patchy.

Blacklegged ticks can be distinguished from other ticks by their coloration.

The mouth parts, legs and scutum are dark brown to almost black.

Males appear to be entirely dark colored because the scutum covers most of the abdomen.

The softer abdominal cuticle of females is usually red in color.

To summarize blacklegged tick or deer ticks can be active from spring throughout the winter and although they frequently feed on deer, nymphs and adults can feed on humans.

These ticks can carry pathogen causing bacteria and viruses and can commonly carry the bacteria that causes Lyme disease.

Blacklegged ticks are identifiable through their coloration.

Their mouth parts, legs and scutum are dark brown to almost black.