LITTLE ROCK, Ark. (AP) — A hardy, invasive species of tick that survived a New Jersey winter and subsequently traversed the mid-Atlantic has mysteriously arrived in Arkansas. No one is sure how the Longhorned tick, native to East Asia, arrived in the country, nor how it made its way to the middle of the continent.

The Arkansas Agriculture Department said late Monday researchers at Oklahoma State University had confirmed a tick found on a dog in Benton County in the far northwestern corner of the state was a Longhorned tick. Until then, the bug had only been reported in New Jersey, Virginia and...