Surveillance of Culicoides biting midges in northern HonshuJapan during the period of Akabane virus spread

摘要

A surveillance of biting midges with light suction traps wasconducted in the northern region of Honshu, main island of Japan, during the summers andautumns of 2009 and 2010. A total of 106 trap collections across 37 cattle farms wereinvestigated for the structure and distribution of species.Forty-thousand and one hundred forty-nine specimens of bitingmidges were identified at the species level, and ≥19 species were included in thespecimens. , which is a known major vector of Akabanevirus (AKAV), appeared not to have expanded in northern Honshu during the surveillance. Ofthe potential AKAV vectors suggested by a previous laboratory experiment, and widely infested cowsheds acrossnorthern Honshu. The AKAV circulation was confirmed by serological surveillance ofsentinel cattle in northern Honshu during the summer and autumn of 2010 and, consequently,>200 calves affected by the virus were identified as of spring 2011. Our surveillancedemonstrated that and werewidely spread and often dominated at cattle farms in/around the seroconverted regions, andour results thus suggest that these species played a critical role in the AKAVtransmission in 2010. Because the distribution ranges of and cover almost all of mainland Japan, a potential risk ofAKAV transmission might be expected even in areas outside the range of .