What do ticks of the genus Adenium look like? - briefly
Ticks of the genus Adenium are small, oval arachnids measuring about 2–5 mm, with a dark reddish‑brown scutum on the dorsal side and lighter, hair‑like setae ventrally. Their capitulum is short and beak‑shaped, and the legs are short and robust.
What do ticks of the genus Adenium look like? - in detail
Adenium ticks are small arachnids, typically ranging from 2 mm to 5 mm in length when unfed. Their bodies are oval‑shaped and compact, with a dorsal shield (scutum) that covers the entire back of the adult female. The scutum is a hard, chitinous plate, often dark brown to black, sometimes exhibiting a faint glossy sheen.
The cephalothorax bears six pairs of legs, each leg ending in a small, claw‑like tarsus equipped with sensory setae. Leg coloration usually matches the dorsal shield, though the ventral side may appear lighter, ranging from pale brown to yellowish tones. The mouthparts (gnathosoma) are short and robust, adapted for piercing host skin and extracting blood.
Sexual dimorphism is evident: males lack a complete scutum, possessing a partially covered dorsal surface, and are generally smaller, measuring 1.5 mm to 3 mm. Their bodies are more slender, and the legs are proportionally longer, facilitating movement in search of mates. Females retain a fully developed scutum throughout their lifespan, providing protection for engorged blood meals.
In the nymphal stages, the exoskeleton is softer and lighter in color, often appearing pale yellow to light brown. As the tick molts into an adult, the cuticle hardens and darkens, acquiring the characteristic glossy appearance. Engorged females can expand dramatically, increasing their body length to up to 12 mm and their weight by several hundred times, resulting in a balloon‑like abdomen that appears pale gray to reddish‑brown.
Key morphological traits include:
- Dorsal scutum: complete in females, partial in males; dark brown to black.
- Legs: six pairs, uniform coloration, ending in clawed tarsi with sensory setae.
- Mouthparts: short, robust gnathosoma for hematophagy.
- Sexual dimorphism: size and scutum coverage differences.
- Color changes: light in nymphs, darkening with maturity; dramatic abdomen expansion in engorged females.
These features collectively define the visual profile of Adenium ticks across developmental stages and sexes.