Would a vial of anticoagulated, warm blood attract mosquitoes?
According to wikipedia they locate "prey" by detecting CO2 and some other compounds, so I don't think mosquitoes will actually find the blood unless they're accidentally right on top of it. 

And for your reason: if you have the equipment to regularly draw some blood, keep it at 37 C and have some anticoagulants on hand, you might be better off using some tried and true anti-mosquito tech (nets, insecticides, preventing them to breed in the local area).

Or maybe this: https://en.wikipedia.org/wiki/Mosquito_laser