How does a tick look at different stages? - briefly
Ticks pass through four stages—egg, six‑legged larva, eight‑legged nymph, and adult—each distinguished by size and body armor. Eggs are microscopic spheres; larvae are ≈0.5 mm and lack a scutum; nymphs are 1–2 mm with a partial scutum; adults reach 3–5 mm (females larger) and bear a complete dorsal scutum.
How does a tick look at different stages? - in detail
Ticks undergo four distinct developmental phases, each with characteristic morphology.
The first phase begins with the egg. Eggs are microscopic, spherical, and translucent, ranging from 0.5 mm to 1 mm in diameter. They are laid in clusters on the ground or in leaf litter and lack any external segmentation or limbs.
The second phase, the larva, emerges as a six‑legged organism. Larvae measure 0.5–1 mm in length, appear pale amber or reddish‑brown, and possess a flat, oval body without a discernible scutum. Their mouthparts are visible as a short, ventral stylet used for piercing host skin.
The third phase, the nymph, is an eight‑legged stage. Nymphs are larger, 1.5–2 mm long, and display a darker brown or reddish hue. A partial scutum may be present, covering part of the dorsal surface. The body remains relatively flat, and the capitulum (mouthparts) is more pronounced, allowing deeper attachment to the host.
The final phase comprises adult males and females, each with unique features.
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Adult male: Length 2–3 mm, coloration varies from light brown to dark brown. The scutum covers the entire dorsal surface, giving a shield‑like appearance. Legs are proportionally longer, facilitating mobility while seeking mates. The capitulum is short, indicating a non‑blood‑feeding role.
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Adult female: Length 3–5 mm, often darker than the male. The scutum is limited to the anterior portion of the dorsum, leaving a large, expandable abdomen for blood storage and egg development. The capitulum is elongated, adapted for prolonged feeding. After engorgement, the abdomen can swell to 10 mm or more, turning a deep reddish‑orange.
These morphological differences enable identification of each stage in field and laboratory settings, supporting accurate monitoring and control measures.