Importation of a New World tick, Dermacentor albipictus (Acari: Ixodidae), with a horse from the USA into Germany

Abstract

In February 2006 an American Bashkir Curly horse was imported via air from Montana, USA into Germany. Already on arrival at the airport of Amsterdam about 30 fully engorged ticks dropped off the horse, and during the following 4 days in the stable in Germany more than 200 engorged ticks were collected. The tick species was identified as Dermacentor albipictus, which is also called ‘winter tick’. Hosts for the ticks are large wild and domestic mammals, such as moose, cows, and horses. On these animals the tick undergoes a one-host life cycle. Larvae become active in summer, nymphs and adults engorge during November and February on the same host. This New World tick species occurs in woodlands of North America up to 60° N in Canada. The ecological conditions in Europe may give a suitable environment for establishing a tick population for D. albipictus. From Germany the occurrence of two similar ticks, Dermacentor marginatus and D. reticulatus, is known. This underlines the importance for an exact species diagnosis of ticks. Ticks of the genus Dermacentor include important vectors of disease agents, such as viruses, rickettsiae, Babesia, and Theileria. Unfortunately, there exist no veterinary regulations by the EU (Brussels) or the OJE (Paris) for prevention of importation of ticks. The horse was treated with permethrin wipe-on. Additionally, all visible ticks were collected by hand dressing and burned. Engorged female ticks were collected for experimental use. In an outdoor experiment female ticks laid eggs under natural German winter conditions. Larvae emerged 25 weeks after engorgement of the females.