What does a common tick look like and how does it differ? - briefly
A common tick is a tiny, oval arachnid with a flat, reddish‑brown body that swells into a balloon‑like form after feeding. Species differ in size, color, and scutum markings, allowing identification of distinct types.
What does a common tick look like and how does it differ? - in detail
A typical tick is a small arachnid, roughly oval when unfed, with a dorsal shield (scutum) covering part of the back in females and the entire back in males. The body consists of a front portion (capitulum) bearing the mouthparts and a larger rear portion (idiosoma) bearing eight legs in adults. Color ranges from reddish‑brown to dark brown, often with a glossy appearance. The legs are relatively long, allowing the animal to grasp hosts securely.
Key distinguishing characteristics among the most encountered species are:
- Deer tick (Ixodes scapularis): small (2–5 mm unfed), dark brown to reddish‑brown, scutum covering only the anterior half in females; legs relatively short; distinctive “tick‑shaped” anal groove.
- Dog tick (Dermacentor variabilis): larger (4–6 mm unfed), brown with a white or ivory‑colored dorsal pattern; scutum fully covers the dorsum in both sexes; legs noticeably longer than those of the deer tick.
- Lone‑star tick (Amblyomma americanum): medium size (3–5 mm unfed), reddish‑brown with a characteristic white spot on the female’s dorsal shield; males lack the spot; scutum pattern varies but often shows festoons along the rear margin.
Life‑stage differences are pronounced. Eggs are microscopic and invisible without magnification. Larvae (seed ticks) possess six legs, measure 0.5–1 mm, and appear pale. Nymphs have eight legs, are 1–2 mm long, and exhibit a darker hue. Adults reach 2–6 mm when unfed; females expand dramatically after feeding, sometimes exceeding 10 mm in length.
Sexual dimorphism appears primarily in scutum coverage and size. Males retain a fully covered scutum, limiting abdominal expansion; they remain relatively small after feeding. Females possess a partially covered scutum, allowing the abdomen to swell as blood is ingested, resulting in a markedly enlarged, rounded appearance.
Engorgement transforms the tick’s silhouette. An unfed adult appears flat and compact; after a blood meal the abdomen elongates, the body becomes balloon‑like, and the overall color may shift to a lighter, more translucent shade. This change aids identification of recent feeding activity.