Early in 2007, during a small-scale survey of the ticks infesting cattle in Azaguié about 50 km north of Abidjan, Ivory Coast, ticks, belonging to a species which to our knowledge had never been reported in West Africa before, were encountered. Boophilus microplus was the only member of this genus collected from cattle in the area. No Boophilus annulatus or Boophilus geigyi were recovered although they had previously been recorded in this region (Aeschlimann 1967). The collection site at Azaguié (5°37′15.63″ N and 4°05′12.76″ W) is situated at an altitude of 85 m above sea level and is best characterised as dense humid forest.

The ticks were initially morphologically identified at the Institute of Tropical Medicine in Antwerp, Belgium, using the identification manual of Walker et al. (2003), after which some were sent to the Faculty of Veterinary Science, University of Pretoria, South Africa for confirmation. At the same time sequencing of the ITS2 region of some of the remaining specimens confirmed the initial identification.

The exact means or route of introduction of B. microplus into the Ivory Coast has not been determined. It has, however, been documented that N’dama bulls were introduced from Lower Congo (Democratic Republic of Congo) in 1985, principally on to the Marahoué Ranch for genetic improvement and subsequently for the establishment of herds of improved cattle for local farmers (Shaw and Hoste 1987). As far as we know B. microplus does not occur in the Congo, nor has it ever been documented in the countries bordering the Ivory Coast. But it has been reported from Zambia immediately to the south (Berkvens et al. 1998).

Historically B. microplus was introduced into East and South Africa from southern Asia via Madagascar after the 1896 rinderpest outbreak (Hoogstraal 1956). Because of frequent importation of infested cattle from Madagascar (Hoogstraal 1956), the geographic distribution of B. microplus in East and South Africa during the first half of the 20th century could well have been more extensive than in the latter half, when climatic conditions and other factors appeared unfavourable for its spread. Recent publications, however, indicate an increased dispersion of B. microplus and/or its displacement of the indigenous Boophilus decoloratus in Zambia (Berkvens et al. 1998), Swaziland (Wedderburn et al. 1999) and Limpopo and Eastern Cape Provinces, South Africa (Tønnesen et al. 2004; Nyangiwe and Horak 2007). Some of the authors (Berkvens et al. 1998) have recorded B. microplus in the Eastern Province of Zambia, at intermediate altitudes where, according to the current knowledge of the tick’s climatic requirements, it would not normally survive.

Further studies on the distribution of B. microplus in the Ivory Coast are contemplated as well as on the climatic suitability of the region for the continued survival and dispersion of the tick.