The brown dog tick, Rhipicephalus sanguineus is probably the tick which the public in Micronesia is most familiar. Kohls (1957) reported it on dogs on Guam, Saipan and Kiribati. Previous to this, Schnee (1904) reported it from cattle in the Marshalls. It is known to be a pest of a wide array of animals. Over fifty years ago, Kohls (1957) considered this tick to be “nearly cosmopolitan.”

Unidentified species from sea krait (Laticauda colubrina)

In their work on Palau, Crombie & Pregill (1999) mention that the sea krait “ Laticauda must come ashore to lay eggs (unlike the live-bearing sea snakes) and they often spend enough time on land to accumulate ticks.” In personal communication with Crombie, he said that he had also found ticks associated with this species of sea snake when it hauled out on land but no identification of the ticks had been made. Although the ticks of sea snakes are poorly studied, other reports tell of Amblyomma (Aponomma) fimbriatum and Amblyomma nitidum, wide ranging ticks, known from this reptile (Rageau & Vervent 1959, Hoogstraal 1982, Voltzit & Keirans 2002, Easton 2003, Nadchatram 2006). None of the other species of ticks reported for Micronesia were found to be associated with sea snakes.

Through the compilation of previous studies, it was found that twenty-nine species of vertebrate hosts are known have been reported as having ticks in Micronesia. These are listed in Table 2.

As with insects, the natural dispersal of ticks is undoubtedly “quite fortuitous,” (Gressitt & Yoshimoto 1963). Therefore, there is reason to suspect and speculate that the species listed in Table 1 are probably not the only ticks to be found in the area if a careful search were to be undertaken at this time. In extensive studies of Arno Atoll in the Marshall Islands, which documented many other ectoparasites of both animals and humans, no ticks were reported (Usinger & La Rivers 1953). On a recent visit, however, residents there were quite familiar with ticks.