COREID BUG

also called leaf-footed bug or squash bug any insect of the family Coreidae (order Heteroptera). This large family contains more than 2,000 widely distributed species, many of which are important plant pests. Coreid bugs are large, usually more than 10 mm (0.4 inch) in length, and dull in colour. They occur in a wide range of environments and vary in size, shape, and colour. Their wings usually lie in a depression on the back. Some feed only on plants, others on insects, and some on both. One of the best-known coreid bugs in North America is the squash bug (Anasa tristis), an important pest of squash, melon, and pumpkin. It is about 15 mm (0.6 inch) long; and, although its basic colour is yellow, it is covered with so many black pits that it appears to be black. Control of this pest is difficult because the larvae feed underground, and the adults, which have piercing and sucking mouthparts, attack the parts of plants that insecticides usually do not penetrate. Squash bugs spend the winter in the adult stage, living in debris or some other sheltered spot. In the spring they deposit conspicuous egg masses on the leaves of young squash plants. There are several generations each season. A number of species of coreid bug (e.g., Leptoglossus phyllopus of North America and L. membranaceus of Australia) have enlarged or flattened extensions on their legs, hence the common name leaf-footed bug. These insects suck plant juices from crops such as peas, beans, potatoes, and tomatoes. Leaf-footed bugs spend the winter in the adult stage. In warm climates there may be two generations a year. They may be controlled by insecticides or by the destruction of hibernation spots and alternate host plants. The box-elder bug (Leptocoris trivittatus) is dark brown with three longitudinal red lines on the thorax and red veins in the first pair of wings. These coreid bugs feed mostly on box-elder trees. They pass the winter in groups in some dry spot, such as under a porch or inside a house. They can be controlled by spraying. The rice bug (Leptocorisa varicornis) does great damage to rice and millet in the Orient. Other Coreidae are known as gum-tree bugs and crusader bugs, the latter deriving from the pale cross on the wings of the Australian species Mictis profana.