Xcode 6.0.1 with iOS 8.1, cannot select iPhone 6+ device

Question

I have my iPhone 6+ for a developer with iOS 8.1.
My iOS8 app is compatible with the minimum target version of iOS up to 7.0.

With Xcode 6.0.1, I can no longer select the 7.0.x simulator and cannot run the application on my device.

Googled, but cannot find and answer.

Answer 1

Solution found.

I had to upgrade to Xcode 6.1 because, as Petes said, Yosemite does not support the 7.0 simulator.