Hello,
There is a USB for IMAQ driver available at:
NI-IMAQ for USB Cameras
http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=ED6942DF78E34659E034080020E74861&p_node=DZ52490&p_source=External
This driver should allow you to interface with your USB camera. Please check the documentation that is available with that download for information on how to use it with LabVIEW.
Regards,
Scott R.
Applications Engineer
National Instruments
Scott Romine
Course Development Engineer
National Instruments