Lettuce Fly
(Anthomyia Lactucae). The larva is at times very destructive to the seed of the garden Lettuce. The eggs are laid on the flower, and the yellowish-white maggots bore into the seed-vessels, eat the seed, and then go on to repeat the process. They change into chestnut-brown oval pupae in the flower-head, or in the ground, towards the end of September or in October. The flies appear in the next spring or summer, and are about the size of house flies. The female is grey, with a chestnut stripe down the face, and blackish legs. The male is black, with the face chestnut-brown; four pale stripes on the front of the thorax; the rings of the abdomen grey, with dark base and triangular spot; legs black, and wings dark.
Prevention. Care should be taken to insure that the seed, when sown, is free from pupae. Infected crops, when cleared off the ground, should be burned.