paraensis is also active diurnally with only a slight apparent peak in host-seeking female activity in the late afternoon ( Mercer et al., 2003 and Roberts et al., 1981). Hence, while the maximum biting rate recorded for C. paraensis is a relatively modest 14.4 adults collected/min on a human subject in Belém, Brazil ( Hoch et al., 1990), their diurnal activity combined with a propensity to enter human housing
( Roberts et al., 1981), leads to a consistent low level of biting in both day and night. Quantifying this biting activity and the resulting impacts on transmission is therefore difficult when using a standard ‘snapshot’ estimate of crepuscular Culicoides abundance. Importantly, these rates appear to be insufficient to trigger changes in human behavior to combat the nuisance and reduce OROV transmission, despite selleck chemicals llc the fact that systematic clearing of larval habitats has been shown to be effective in reducing C. paraensis numbers ( Hoch et al., 1986). In addition to OROV, Culicoides may see more also play a limited
but poorly defined role in the transmission of many other zoonotic arboviruses of global importance ( Table 2). By far the best characterized of these is vesicular stomatitis Indiana virus (VSIV), though research concerning the transmission of this virus by Culicoides has been entirely focused on ruminants ( De Leon and Tabachnick, 2006, Drolet et al., 2005 and Nunamaker et al., 2000). This is because cases of human disease arising from arthropod transmission of VSIV are thought to be extremely rare ( Krauss et
al., 2003 and Letchworth et al., 1999). Of the other human pathogenic arboviruses that have been detected in field-caught adult female Culicoides, oral susceptibility has only been investigated in detail for Rift Valley fever virus (RVFV), following initial detection in field populations. In this study RVFV failed to replicate in 135 individuals of a C. sonorensis colony line derived from a population originally colonized Rutecarpine in the USA ( Jennings et al., 1982). The public health importance of Culicoides biting midges in Europe is currently restricted to biting nuisance, largely inflicted by a single species, C. impunctatus. While this species is widespread and abundant in many northern European countries, including the Netherlands ( Takken et al., 2008), the vast majority of detailed studies of C. impunctatus have centered on populations in the Scottish Highlands ( Blackwell, 2001 and Stuart et al., 1996). Here, the abundance of C. impunctatus vastly exceeds that recorded in the rest of northern Europe and can result in biting rates on humans that exceed those recorded for the vast majority of haematophagous dipteran species worldwide, with a maximum of 635 C. impunctatus collected/minute on human bait arms in Ormsary, UK ( Carpenter et al., 2005). In contrast to C. paraensis, C.