Libgdx does not support primitives as such. You're on your own.
My advice: Export the sucker from a 3d modeller and load as an obj. Applying texture to that is trivial.
Check this out: http://code.google.com/p/libgdx/source/browse/trunk/tests/gdx-tests/src/com/badlogic/gdx/tests/ObjTest.java
However, if you must create a sphere at runtime you'll have to implement the creation of the vertices & texture coordinates yourself and stuff them into a mesh. I'm sure you could find quite a few algos on the web re: sphere mesh creation.