What does an encephalitis tick look like and what are its dimensions? - briefly
The encephalitis tick is a small, oval arachnid with a reddish‑brown dorsum, lighter ventral side, eight legs, and a scutum covering the back in adult females. Adult individuals range from about 2–4 mm in length when unfed to roughly 8–10 mm after engorgement.
What does an encephalitis tick look like and what are its dimensions? - in detail
The tick responsible for transmitting encephalitis exhibits a compact, oval body covered by a hardened dorsal shield (scutum) that is typically dark brown to reddish‑brown in color. Eight robust legs extend from the anterior region, each ending in small claws that aid attachment to host skin. The mouthparts, located on the ventral side, form a short, pointed proboscis capable of penetrating deep into tissue.
Dimensions differ markedly between life stages and feeding status:
- Unfed adult: length 2 – 3 mm, width 1.5 – 2 mm; overall shape resembles a flattened disk.
- Engorged adult: length expands to 10 – 12 mm, width up to 8 mm as the abdomen fills with blood.
- Nymph: length 1 – 2 mm, width approximately 0.8 mm; coloration lighter than the adult, often mottled.
- Larva: length 0.5 mm, width about 0.3 mm; translucent to pale yellow, lacking a distinct scutum.
The dorsal shield occupies roughly half of the adult’s back, leaving the remaining surface visible as a softer, lighter‑colored area that stretches over the abdomen. When fully engorged, the tick’s body becomes noticeably rounded and swollen, with the scutum remaining unchanged in size while the surrounding tissue expands. This morphological pattern assists in distinguishing the species from other ixodid ticks in field and laboratory identification.