REDUCTION OF CULISETA-MELANURA FITNESS BY EASTERN EQUINE ENCEPHALOMYELITIS VIRUS

The traditional view of interactions between arboviruses and their art hropod vectors is that vector hosts become increasingly resistant to p arasites; parasite attenuation occurs; or through the process of coevo lution, resistance and attenuation occur in concert. Detrimental effec ts from arboviruses are only seen when vector and virus are not yet we ll adapted. Results from this study indicate that eastern equine encep halomyelitis (EEE) virus reduces survival and reproduction (fitness) o f the mosquito Culiseta melanura, which is required for transmission o f EEE virus in North America. Mosquito virulence was not measurably at tenuated in virus isolates recovered 55 year apart. This virus did not affect the ability of mosquitoes to obtain a blood meal or the rate o f mosquito oocyte development. Results from this study support those f rom earlier investigations with other mosquito-virus interactions and suggest that reproductively successful arboviruses can have detrimenta l effects on their mosquito vectors.