[Pest Profile]

Blacklegged Ticks

Order/Family: Acari/Ixodidae

Scientific Names: Ixodes scapularis Say Deer/Bear,

Ixodes pacificus Cooley and Kohls Pacific/Western

Description

Blacklegged ticks are hard ticks, 1/16- to 1/8-inch long, and orange-brown except for the head, shield behind the head and legs that are dark reddish-brown. Their bodies are flattened and shaped like a tear drop. Unlike adults, which have eight legs, larvae have six legs and are 1/32-inch long.

Biology

During the winter, adults feed on deer. In the spring, engorged females drop off of the host animal and lay 3,000 eggs in a protected area. The eggs hatch in 48 to 135 days and the larvae seek and feed on small rodents. After molting to the nymphal stage, the ticks once again seek hosts and feed only once for three to nine days on larger animals. After 25 to 56 days, engorged nymphs molt to the adult stage which usually feed on deer.

Habits

The deer/bear blacklegged tick is found east of the Mississippi River. The western/Pacific blacklegged tick is found along the West Coast and into Arizona. These ticks are three-host ticks, i.e., they require different and successively larger host animals in order to complete development. Blacklegged ticks climb grass and shrubs and wait for host animals. Typically, they are concentrated in transition areas between fields and lower grassy vegetation, along animal trails and in host animal nests and dens, such as woodpiles, burrows in the ground, stumps, logs, old rat and bird nests and crawlspaces.

Control

Control of blacklegged ticks involves five steps: sanitation, personal protective measures, inspection, tick control and rodent control. These ticks are rarely, if ever, encountered, nor do they survive, indoors. Control of blacklegged ticks begins with sanitation. Tick harborage and questing areas (places where ticks wait for a suitable host to pass) should be reduced by mowing the grass and by removing and cutting high grass and weeds along paths, the fringe of turf areas, and areas frequented by humans and their pets. Perimeter areas should be inspected for ticks and evidence of rodent activity. Rodent populations should be eliminated by using traps, tracking powders and/or baits. In perimeter areas, residual pesticides should be applied to rodent runs, nesting areas, vegetation along paths and trails, and grassy areas including lawns, using liquids with spreader stickers, microencapsulated and wettable powder formulations.