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American Dog Tick

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Life Cycle

The American dog tick is a three-host tick – each development stage feeds on a different host.

Newly hatched larvae are yellow with red markings near the eyes, while engorged larvae are slate-grey to black. It feeds on rodents such as the meadow vole and white-footed mouse for 3 to 6 days and then drops from the host.

Figure 1: Larva of the American dog tick.

After about a week, it casts off its skin to become an eight-legged nymph. The nymph feeds for a similar length of time on another small mammal, then drops to the ground, where, after 2 to 3 weeks, it becomes an eight-legged adult.

Figure 2: Nymph of the American dog tick.

Larvae usually engorge for 3-5 days, nymphs for 3-11 days, and adult females for 5-13 days. Unfed larvae can live up to 15 months, nymphs 20 months, and adults 30 months or longer.

Adults prefer larger mammals, including dogs and humans. The male mates with the feeding female after his brief bloodmeal and does not become distended with blood. The female feeds for 7 to 10 days, drops to the ground, and after several days, lays 4,000-6,500 ellipsoidal eggs over a 14-32 day period. The eggs usually hatch in 36- 57 days. The female usually dies shortly after the eggs begin to hatch.

Figure 3: Adult male of the American dog tick.

   

Figure 4: Adult female of the American dog tick.

Adults are most abundant from mid-April to mid-July. Once on the host, they crawl upward, seeking a place to attach and take a bloodmeal.

   

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