Submitted to: American Society of Tropical Medicine and Hygiene
Publication Type: Abstract Only
Publication Acceptance Date: September 8, 2008
Publication Date: December 7, 2008
Citation: Bennett, K.E., Hopper, J.E., Stuart, M.A., West, M.S., Drolet, B.S. 2008. Effects of Viral Infection on Blood Feeding Behavior and Fecundity in Culicoides Sonorensis (Diptera: Ceratopogonidae). American Society of Tropical Medicine and Hygiene. Interpretive Summary: Culicoides sonorensis (Diptera: Ceratopogonidae) is the primary vector of bluetongue virus (BTV) in North America and has been shown to be a competent vector of vesicular stomatitis virus (VSV). To determine whether infection with VSV or BTV affects blood feeding, midges were injected with VSV, BTV, or virus-free cell lysate and held 2, 3, or 4 days post inoculation (DPI) for VSV or 2, 4, or 7 DPI for BTV before being offered a non-infectious blood meal. Viral growth curves were determined for each virus. Measurements of fecundity, egg viability and days from hatching to the emergence of pupae were taken for individual females. The effect of viral infection in C. sonorensis on virus transmission and epidemiology is discussed.
Technical Abstract: Culicoides sonorensis (Diptera: Ceratopogonidae) is the primary vector of bluetongue virus (BTV) in North America and a competent vector of vesicular stomatitis virus (VSV). Little is known about how viral infection of this midge affects its blood feeding behavior and fecundity. Blood feeding success of midges intrathoracically inoculated with either virus-infected or virus-free cell lysate was measured at 2, 3, and 4 days post inoculation (DPI) for a study of VSV and at 2, 4, and 7 DPI for a study of BTV. Viral growth curves were determined for each virus, and blood meal DPI were selected to include the normal optimal blood feeding time point (2 DPI) and peak virus titer in the insects. To determine effects of infection on feeding, midges were offered a non-infectious artificial blood meal for a short (10 minutes) or long period (60 minutes) and proportions of fed midges were compared using a generalized linear mixed model. Fecundity, egg viability, and the number of days from initial hatching to pupation were measured for egg clutches from individual females, and results were compared based on virus infection status and the number of DPI that a blood meal was taken. The potential consequences of altered blood feeding behavior and fecundity on virus transmission and epidemiology are discussed.