What do tick larvae and adult ticks look like? - briefly
Tick larvae are microscopic, six‑legged, translucent or pale bodies measuring under 0.5 mm that appear as tiny specks. Adult ticks are considerably larger, eight‑legged, with a hardened, oval dorsum 3–5 mm long (up to 10 mm in some species) and coloration ranging from brown to reddish.
What do tick larvae and adult ticks look like? - in detail
Tick larvae, often called seed ticks, are the smallest life stage. Their bodies measure 0.1–0.5 mm in length, appear translucent to pale yellow, and lack the distinct dorsal scutum seen in later stages. Six legs are present, arranged in three pairs, each leg ending in a tiny claw. The mouthparts are short and not visible without magnification. Sensory organs are reduced, giving the larva a smooth, rounded silhouette.
Adult ticks are considerably larger, ranging from 2 mm in small species to over 10 mm in engorged females. The dorsal surface is covered by a hardened shield (scutum) in males and non‑engorged females; this shield is typically brown, reddish‑brown, or black, with distinct patterns that vary by species. Adults possess eight legs, each ending in a well‑developed claw for attachment. The capitulum, located at the front, includes elongated chelicerae and a hypostome with backward‑pointing barbs that facilitate blood feeding. In females, the abdomen expands dramatically after a blood meal, turning the body into a balloon‑shaped, engorged mass that can increase severalfold in size. Males retain a relatively flat, oval shape, with a smaller abdomen and more pronounced scutum.
Key morphological differences:
- Size: larvae < 0.5 mm; adults up to > 10 mm.
- Leg count: six in larvae, eight in adults.
- Scutum: absent or faint in larvae; prominent in adult males and unfed females.
- Coloration: pale, translucent in larvae; darker, patterned in adults.
- Abdominal shape: round and compact in larvae; flat in males, dramatically expanded in engorged females.