Understanding factors that can influence arbovirus infection and transmission between an infected vector and host is critical for increasing forecasting and control of arboviral outbreaks. By examining spatial and temporal conditions associated with arbovirus transmission we may identify predictors of transmission indices. We monitored field sites in three counties in Florida, trapping mosquitoes during the 2005, 2006 and 2007 arbovirus transmission seasons using chicken baited traps. This process enables us to examine both infection rates in mosquito pools as well as transmission rates of the virus from mosquito to chicken. Mosquitoes were pooled by species and tested for West Nile virus (WNV) and St. Louis encephalitis virus (SLEV), and chicken sera were tested for antibodies to both arboviruses. We also examined variables that may significantly influence mosquito infection and transmission dynamics, such as the age structure of the mosquito population. Age structure was measured by looking at parity rates in mosquito collections using several collection methods. Arbovirus transmission was low in 2005 and 2006; only one chicken seroconverted to WNV. In 2005, Cx. nigripalpus was the only mosquito species that tested positive for WNV, further implicating this species in field transmission. Mosquito abundance varied between the years, sites, and collection periods. This research enables a more complete understanding of the field dynamics of the arboviral cycle, including factors that may enhance or suppress transmission. Increasing our understanding of this complex cycle will allow for a greater ability to predict and control arboviral outbreaks.