April 2011. An extensive survey of parasites and diseases on domestic animals in the early 1990s found no evidence of ticks on Rarotonga, Cook Islands. However, recently ticks were collected from puppies.

Are they Rhipicephalus sanguineus, the Brown dog tick?

Identification is based on the hexagonal dorsal basis capitulum, deeply cleft first coxa, close proximity of first leg to snout, and red legs. The closely related “cattle tick” Rhipicephalus (Boophilus) microplus is recorded in French Polynesia, but it seems that its first coxa is only shallowly cleft, its first leg is not close to the snout, and it has cream legs.

In the Cook Islands, all imported livestock require a veterinary certificate to indicate recent control of parasites among other things, so it is surprising that we now have ticks. Furthermore, most livestock comes from New Zealand, which has only one resident tick, the “cattle tick” Haemaphysalis longicornis.

AgResearch Lincoln, which has been working on tick taxonomy for some time now, confirmed that the tick is most likely Rhipicephalus sanguineus. R. sanguineus is definitely known from Australia, Vanuatu, Hawaii, Fiji, and Okinawa and it is believed to be cosmopolitan between 50N and 30S (in the words of Walker, Keirans and Horak “R. sanguineus is probably the most widely distributed tick in the world” (Walker JB, Keirans JE, Horak IG (2000) The genus Rhipicephalus (Acari, Ixodidae): A guide to the brown ticks of the world. Cambridge University Press.