Identification of Culicoides obsoletus (Diptera: Ceratopogonidae) as a vector of bluetongue virus in central Italy

Abstract

In 2001 and 2002, 235 outbreaks of bluetongue were observed in the Lazio and Tuscany regions of central Italy. During entomological surveillance Culicoides imicola, the main vector of bluetongue virus in the Mediterranean region, was detected in only 14 of 28 municipalities affected by outbreaks; Culicoides obsoletus was the most abundant species, contributing 83 per cent of individuals in catches, whereas C. imicola contributed only 2 per cent. In affected municipalities the maximum catch of C. obsoletus was 18,000 specimens, compared with 54 of C. imicola. In October 2002 bluetongue virus serotype 2 was isolated from a single pool of wild-caught, non-blood-engorged parous C. obsoletus inoculated on to BHK-21 cells. Its identity was confirmed by reverse transcriptase-PCR.

Drosophila melanogaster as a Model Organism for Bluetongue Virus Replication and Tropism

“…However, the recent BTV-8 outbreak in Northern Europe occurred beyond the northernmost limit of C. imicola (47), confirming earlier studies that had implicated Palearctic Culicoides species in the transmission of this virus (15). This hypothesis was later confirmed by the isolation of BTV from field-collected specimens that belong to the Culicoides obsoletus and Culicoides pulicaris groups, which are abundant in Central and Northern Europe (13,20,66), and the successful infections of both groups in the laboratory (14). In light of this evidence, the whole of Europe is currently regarded as "at risk" for the emergence of bluetongue and other arthropod-borne diseases (33,44,58).…”

The phenology and population dynamics of Culicoides spp. in different ecosystems in The Netherlands

“…Both species are confirmed vectors of BTV in Italy and suspected vectors on the Balkan (De Liberato et al, 2005). Although these species were not expected to be active after the first nights with frost in October, in November 2005 we found C. obsoletus still active in one of the farms, suggesting that host seeking was still occurring relatively late in the phenological season.…”

“…scoticus, C. dewulfi and C. chiopterus as well as the African vector C. imicola (Gomulski et al, 2005). C. obsoletus and C. scoticus have been incriminated as bluetongue vectors in Italy (De Liberato et al, 2005). C. dewulfi is the only species from which bluetongue virus was identified during the bluetongue outbreak in the Netherlands of 2006 2 although in a C. obsoletus pool in Germany viral DNA was also detected.…”

A Mini-review of Culicoides (Diptera: Ceratopogonidae) Fauna and its Vectorial Role in Tunisia

“…The two pathogens are responsible of devastating diseases in ovine and equidae, respectively. It is important to note that other species including Culicoides obsoletus, Culicoides scoticus, Culicoides dewulfi and Culicoides pulicaris are considered as known or potential bluetongue virus vectors [14][15][16][17][18][19][20]. In Tunisia, the first outbreaks of bluetongue virus (BTV) were identified in 1999 causing a dramatic sanitary and economical crisis in the country [21].…”