Comprehensive DescriptionRead full entry
General DescriptionDermacentor andersoni are brown ticks with a light silver-gray ornamentation on the dorsal scutum ('shield"), dorsal portions of the legs and on the basis capitulum ("mouthpart"). Adult female ticks are 2.8 to 5.4 mm long when unengorged and 13.8 mm to 16.5 mm long when engorged. The dorsal scutum ("shield") covers the anterior half of the idiosoma ("body"), while the posterior half of the idiosoma is brown coloured. The spiracular plates are oval shaped and have a long and thin dorsal prolongation. Adult male ticks are from 2.1 mm to 6.1 mm in length. The scutum covers the entire dorsal surface of the idiosoma. The spiracular plate has a more rounded shape, fewer goblets and a shorter dorsal prolongation than female ticks. The size and number of goblets on the spiracular plates differentiates the three Dermacentor species in Canada. Dermacentor andersoni have 100- 200 moderately sized goblets, D. albipictus have many large sized goblets, and D. variabilis have more than 300 small goblets. Dermacentor hunteri also has similar-sized and the same number of goblets as D. andersoni. However, D. andersoni is distinguished from D. hunteri by the large and deep punctuations of the scutum. Additionally, D. andersoni has a long and thin dorsal prolongation of their spiracular plates and have a reduced number of goblets near the dorsal prolongation. For both sexes, the goblets of D. andersoni are large in the middle and is surrounded by numerous pore-like structures in the peripheral region.