Which tick species follows a one-host lifecycle?

• A. Rhipicephalus annulatus
• B. Haemaphysalis longicornis
• C. Amblyomma maculatum
• D. Dermacentor andersoni

Answer: (A)

One-host lifecycles occur when the larva, nymph, and adult all feed on the same individual host and complete development there, with the tick dropping off only after the final engorgement to lay eggs. The cattle fever tick, Rhipicephalus annulatus, is the classic example of this pattern: larvae attach to a single animal, molt to nymph on that same host, then to adult while still on that host, and only after the adult engorges does it leave to reproduce. The other listed ticks typically use a three-host lifecycle, feeding on different hosts at each stage, so they don’t fit the one-host pattern. Therefore, Rhipicephalus annulatus is the one-host lifecycle tick.