Cabbageworm, Imported Cabbageworm
Order Lepidoptera, family Pieridae, Pieris rapae
Adult--1 1/2", larva--up to 1 1/4"
Adult is a fast-moving, pretty, small white butterfly with black tips on its wings. Eggs are tiny yellow cones. Larvae are pretty little light green worms.
Pupae overwinter in garden debris. Adults emerge in the spring and lay eggs on plant foliage. Larvae feed for two to three weeks. Several overlapping generations per year. Complete metamorphosis.
Broccoli, cabbage, brussels sprouts, cauliflower, and other leafy garden plants.
Larvae eat ragged holes in leaves and heads of cabbage, cauliflower, broccoli, and other leafy vegetables. They leave a trail of droppings.
Destruction of garden crops.
Parasitic wasps, yellow jackets, insectivorous animals. Plant early-maturing varieties.
Control: Bacillus thuringiensis products, floating row covers. Release of beneficial wasps. The time to release trichogramma wasps is when you see the pretty little white butterflies fluttering around and landing on your vegetable plants. Make a release prior to this time for even better control. These beautiful little female butterflies lay a translucent egg on foliage every time they light. Don't let their delicate beauty fool you. These little green worms are very destructive.
Will often hide in the heads of cut broccoli. Soak heads in salty water to drive pests out--unless you like a little protein with your veggies. It's easier to see the light green worms on plants with purple foliage.