QtCreator .pro file question

I can't seem to get a library linked. The library is libusb-1.0.

I have the following line in my .pro file:
LIBS += -L/usr/local/lib -llibusb-1.0

I get the following error during a build (clean/qmake/rebuild all):
/usr/bin/ld: cannot find -llibusb-1.0

I'm sure that the library is on my system. The results of #locate libusb-1.0:

/usr/local/include/libusb-1.0
/usr/local/include/libusb-1.0/libusb.h
/usr/local/lib/libusb-1.0.a
/usr/local/lib/libusb-1.0.la
/usr/local/lib/libusb-1.0.so
/usr/local/lib/libusb-1.0.so.0
/usr/local/lib/libusb-1.0.so.0.0.0
/usr/local/lib/pkgconfig/libusb-1.0.pc

I tried changing the .pro line to all of these with no success:
LIBS += -L/usr/local/lib -llibusb-1.0.so
LIBS += -L/usr/local/lib -llibusb-1.0.so.0
LIBS += -L/usr/local/lib -llibusb-1.0.so.0.0.0

Any ideas what I'm not doing or doing incorrectly?

Thanks!