Entomological surveillance for bluetongue on Malta: first report of Culicoides imicola Kieffer

A survey for Culicoides Latreille, 1809, was made on Malta in 2002 to establish whether Culicoides imicola Kieffer, 1913, the principal vector of bluetongue virus (BTV) in the Mediterranean Basin, or any other suspected vector species, was present. The collections and analyses were performed in accordance with the protocols of the National Reference Centre for Exotic Diseases (CESME Centro Studi Malattie Esotiche) in Teramo, Italy. Eighty-four catches were made between May and October at six permanent sites, namely: Mellieha, Rabat, San Gwann, Zejtun (Malta), Gharb and Sannat (Gozo island). The traps were placed near cattle (four farms), cattle and sheep (one farm: Rabat) and sheep and goats (one farm: Mellieha). Culicoides midges were found in 91.66% (77/84) of the catches and the highest number of midges per catch was 1 726. Culicoides imicola was confirmed on Malta for the first time in October 2002 and was found at four sites (San Gwann, Sannat, Gharb and Mellieha) but at very low abundance levels (<0.1% of the total Culicoides collected). Culicoides paolae Boorman, 1996 was the most widespread and abundant species (more than 80% of total Culicoides). Midges of the Obsoletus Complex were rare, with less than 10 individuals captured. Other species of Culicoides identified in the collections were: C. submaritimus Dzhafarov, 1962, C. cataneii Clastrier, 1957, C. circumscriptus Kieffer, 1918, C. jumineri Callot and Kremer, 1969, C. kingi Austen, 1912, C. maritimus Kieffer, 1924 and C. newsteadi Austen, 1921.