Matthew Debacco has created an excellent guide with pictures to help identify pumpkin plant problems.  I have posted his guide here:  Pumpkin diseases and plant problems


Information about pumpkin diseases can be found here:

Pumpkin Disease Information
Additional Pumpkin Disease Information

Insects that do damage:

The cucumber beetle is my number one enemy each year.  You can find information about this insect and how to control it here:

Information about the vine borer can be found here: