The adult moths tend to be greyish-brown and have darker brown distinct lines on their wings. Each spring, adult female moths lay eggs on the undersides of corn leaves as well as within the corn silks. Typically only single eggs are laid within the silk. When the earworm larvae hatch from the eggs, they feed on nearby leaves and their feeding can stunt the overall growth of the crop. However, the worst case of earworms is one where the worms have fed on the silks which can result in poor pollination and interrupted kernel development.
Corn earworms can produce several generations within a growing season.
In order to use insecticides effectively, you need to treat the corn earworms before they bore into the ears. Dusting the garden with carbaryl can be an effective treatment. If you repeat the application at intervals of three days for three or four applications you should effectively control the earworms. However, if reinfestation occurs you can safely treat the corn at intervals of three days right up until the time of harvest if necessary. Learn more about the corn disease heliothis zea, the corn earworm also known by tha names tomato fruitworm and cotton bollworm.