It sounds like these are wireworms. They are slender worms yellow to brown in color, and range from 1/2 to 1 1/2 inches long. They overwinter deep in the soil, and then move to the soil surface when temperatures are around 50 °F. Once the pest is in the bulbs, there is no control. Some things you can do include cultivating regularly to make conditions unfavorable for egg laying and to expose the pest to weather and natural enemies; and using raw potatoes or carrots as a trap crop. Cut the potato in half and spear it with a stick. Bury it about 1 to 2 inches deep so the stick is protruding from the soil. Every couple of days remove it and destroy. You might check with a local extension service as pesticide recommendations vary by state.