Green, hairy cabbageworms have a velvety appearance and a row of light spots along their backs. These voracious feeders eat vegetable plant leaves, creating large, irregular holes, often along the midrib. When feeding on cabbage, these worms bore directly into the head. Their excrement consists of greenish-brown pellets. After two to three weeks of feeding, the wormlike larvae pupate and attach themselves to stems by a silk thread. The adult form, the imported cabbageworm butterfly, is easy to spot. It's white, with one to four black spots on its wings. Read more about controlling cabbage worms.