[Drosophila] Species identification

[Mark Thorson]

Now that I've scaled up my cultures so I'm
using at least half a dozen bananas every day,
I'm attracting quite a few wild flies.  I killed
more than a dozen yesterday.  Most are obviously
Drosophila, but a few (maybe about a third) are
a larger species.  It's a little less than
double the linear size of Drosophila, and it's
all black.  I'm in California.  Anybody know
what species this is?  I don't have a photo, yet.