Technical Abstract: West Nile virus (WNV) was first introduced into the U.S. in 1999. The fatality rates for organisms that contract this virus are up to 100% in some avians, 33% in equines, and around 10% in humans. A mosquito species capable of transmitting this disease is the Culex quinquefasciatus, the "Southern House mosquito." In laboratory rearing of this species, the females are provided bloodmeals of bovine blood; the odors produced by this blood are highly attractive for this species. Currently, good attractants are needed for mosquito traps to enhance surveillance accuracy by more efficient trapping of Culex spp. mosquitoes. Solid phase microextraction (SPME) fibers were used to extract compounds both in the headspace above blood and from immersion directly into blood for subsequent analysis by gas chromatography/mass spectrometry. Volatile compounds, such as acetone, dimethyl disulfide, and 2-pentanone were identified tentatively in the headspace above bovine blood. Additionally, numerous hydrocarbons were observed. Substituted benzenes were observed in the headspace, while substituted pyrazines were observed from the direct blood extraction. Neither of these classes of compounds were detected in the analysis of blanks. Further experiments to identify the headspace volatiles from bovine blood are ongoing; these involve direct injection of the headspace above the blood, microscale purge and trap GC/MS analysis of the headspace, and collection of the volatiles on Tenax, followed by elution off of the Tenax by solvents and analysis of fractions