Our three species of hard ticks are mites with 8 legs, a small plate over their mouthparts, and skin so tough it’s hard to crush one. Adults are 1/16 to 1/4 inch long (about the size of a sesame seed). When engorged with blood, they swell up to about 3/8 inch long and turn gray. During the larval “seed tick” stage, ticks have 6 legs and are about as large as a poppy seed.
Three species of hard ticks are commonly encountered in Missouri. Most common are the lone star tick (Amblyomma americanum) and American dog tick (Dermacentor variabilis). The deer tick, or blacklegged tick (Ixodes scapularis), is also common.
Lone star tick — Females are easily identified by the white dot in the center of the back. Males often have dots or white streaks on the edge of their bodies.
American dog tick — Newly hatched larvae are yellow. Adults are brown. Blood-engorged females are gray.
Deer tick (blacklegged tick) — Legs and upper body are black.