What are the visual, behavioral similarities and differences between Yellow Fever Mosquito (Aedes aegypti) and the Tiger Mosquito (Aedes albopictus)?
For the best way to tell them apart, see this guide: http://www.cdc.gov/dengue/resources/30Jan2012/comparisondenguevectors.pdf

Specifically, it seems that the silver pattern on the torso is different (lyre-shaped for Yellow Fever Mosquito, more linear for Asian Tiger Mosquito).  Location is probably also an important determinant.