Bob,
Sounds like you may have larvae of the moth Exyra. These moths lay their
eggs in the pitchers, and the larva chews a hole to prevent water from
collecting in the pitcher and drowning it. Did you notice a lot of loose
material inside the pitcher. This would be the fecal matter from the
caterpillar produced as it eats the inner surface of the leaf. You'll
probably have to look your plants over carefully, and remove any other
larvae.
Good luck,
Liane Cochran-Stafira
Dept. of Ecology and Evolution
The University of Chicago
1101 East 57th Street
Chicago, Illinois 60637-5415
lcochran@midway.uchicago.edu