Thank you for your inquiry and accompanying pictures.  Someone has apparently been enjoying your late peas. Sorry it wasn't you!   Caterpillar?  If you see any frass (droppings) on the plant or on the ground under the plant, look for caterpillars.  Other possible insect pests of green and dry peas: 

• Aphid

• Armyworm and cutworm

• Grasshopper

• Leaf miner

• Looper

• Pea leaf weevil

• Pea moth

• Pea weevil

• Seed corn maggot

• Thrips

• Wireworm

Additionally, earwigs, slugs, snails, birds...   

You may also want to be on the lookout for fungal disease, such as 'Pea (Pisum sativum)-Powdery Mildew'. 

  Thank you!

https://pnwhandbooks.org/plantdisease/host-disease/pea-pisum-sativum-powdery-mildew

https://pnwhandbooks.org/insect/vegetable/vegetable-pests/hosts-pests

Rodale’s Garden Problem Solver.  Vegetables, fruits and Herbs by Jeff Ball