nigripalpus shows an early- to late-season feeding shift from ornithophilic to opportunistic (Edman and Taylor 1968, Tempelis 1975). Louis encephalitis virus (Sudia and Chamberlain 1964, Dow et al. nigripalpus is also an efficient laboratory vector of WNV (Sardelis et al. nigripalpus was shown to transmit WNV to sentinel chickens in nature in Florida (Rutledge et al. nigripalpus support its likely involvement in this arbovirus transmission cycle (Blackmore et al. Studies showing WNV-positive field-caught Cx. 1980, O'Meara and Evans 1983, Day and Curtis 1989, Zyzak et al.
![cc maker virus cc maker virus](https://www.goodnewsnetwork.org/wp-content/uploads/2016/02/OFF-and-mosquito-CC-Mike-Mozart-CC-Katja-Schultz.jpg)
This species is found throughout Florida and is most abundant during summer and fall (Mitchell et al. Culex nigripalpus Theobald is a subtropical mosquito distributed throughout the southern United States, the Caribbean, and Central and South America (Day 2004, Darsie and Ward 2005). W est Nile virus (WNV family Flaviviridae: genus Flavivirus) is maintained in an enzootic transmission cycle between birds and Culex spp.
![cc maker virus cc maker virus](https://i1.rgstatic.net/publication/353252972_Leaf_Plasmodesmata_Respond_Differently_to_TMV_ToBRFV_and_TYLCV_Infection/links/60ef8fee16f9f3130083de71/largepreview.png)
The complex relationships between infection, dissemination, and transmission must be evaluated under a variety of biological and environmental conditions to begin to assess the epidemiological risk of natural mosquito populations. Therefore, characterizing the transmission ability of a vector population using infection or dissemination as indicators of transmission may provide inaccurate information. We show that not all mosquitoes with infections and/or disseminated infections transmit WNV under the conditions of this test. Virus titers in body and leg tissues were significantly lower at the low dose and the titers were not influenced by IP. Despite 100% infection and 90% dissemination in the most permissive treatment of high dose and 12 days, only 11% transmission was observed. Dissemination rates were significantly higher at the high dose, and this was dependent on IP. Infection rates were not influenced by dose or IP. Vector competence was measured using rates of infection (% with WNV-positive bodies), dissemination (% infected with WNV-positive legs), and transmission (% infected with WNV-positive saliva). Female Culex nigripalpus were fed blood containing a low dose (6.3☐.01 logs plaque-forming units (PFU)/mL) or high dose (7.3☐.1 logs PFU/mL) of West Nile virus (WNV) and maintained at 28☌ for incubation periods (IPs) of 6 or 12 days.