Amblyomma triste (Acari: Ixodidae): new North American collection records, including the first from the United States.

New distribution records for the Neotropical tick, Amblyomma triste Koch, are identified from 27 specimens in 18 separate collections. These collections originated from six now recognized geographical foci in two states in the United States (Cochise and Santa Cruz Counties, Arizona, and Brewster and Jeff Davis Counties, Texas) and from import cattle, Bos taurus L., presented for entry at the United States border and originating in three Mexican states (Coahuila, Durango, and Sonora). For at least 67 yr, A. triste has existed in some areas of the United States as a cryptic species, and specimens there have been confused with and identified as Gulf Coast ticks, Amblyomma maculatum Koch, even by noted tick specialists. Most of the records reported in this study were from reidentified, archived specimens of putative A. maculatum.