Phyllid Leaf Bugs
Occasionally kept as pets, these leaf insects are native from India to the Fiji Islands, and about 30 species exist. Almost 2 1/2 inches long, they mimic leaves so closely in color and shape that the wings appear to have midribs and veins as well as natural-looking leaf margin irregularities and discolorations. Males and females have different shapes. Males have narrow bodies and can fly, and females are broad and flattened, with large forewings extending completely over the abdomen. They can't fly.
Capsid Leaf Bugs
The entire family Capsidae, formerly known as Miridae, can be called leaf bugs or plant bugs. They are characterized by two main cells formed by wing veins in the outer set of wings. They are usually small and slender and often brightly colored, with over 250 kinds native to North America. One of the commonest leaf bugs is the four-lined leaf bug, found throughout the U.S. east of the Rockies. Immature insects are red, and adults are orange-yellow with green wings marked with four black stripes. They suck sap from a wide variety of plants, including gooseberries and currants.
Ash-Gray Leaf Bugs
Belonging to the true bug family Piesmatidae, ash-gray leaf bugs are less than a quarter of an inch long. Yellowish-gray in color, they have lacelike patterning at the base of the forewings and short spines between the eyes and antennae. They feed on sap of herbaceous weeds, especially pigweed. They hibernate during the winter under tree bark and are native to the Great Lakes region.
Other Leaf Bugs
Flatid leaf bugs, related to leafhoppers and treehoppers, have very different immature and adult forms. Adults are pink to pinkish-green and flattened from side to side, and resemble flower petals. Immature nymphs extrude long white filaments of wax from their backs that curl and fork, hiding their bodies from view. These Madagascan leaf bugs also suck plant sap. Some katydids closely resemble leaves. These grasshopper relatives have strong chewing mouthparts and feed primarily on leaves. They are common in the U.S., but the katydids that most closely mimic leaves live in the American tropics. Katydids have long antennae, leathery forewings and long hind legs for jumping. Male katydids sing at night.