Answer: Sounds like pickleworm damage. While they prefer cucumbers, they will attack any member of the cucurbit family, pumpkins included. They typically feed on foliage first and then migrate towards the fruit. Once you see a hole, it's too late to control that particular worm and I'm afraid the pumpkin will eventually rot rather than growing to maturity. Carefully inspect your plants for these little worms. If you find any, hand pick them or use Bt (sold as Dipel or Thuricide). Bt is a bacterium that works as a stomach poison on caterpillars but won't harm other insects. Good luck with your pumpkins!
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