Greenbugs are small, lime-green or yellow aphids that concentrate in colonies on the undersides of leaves. They have a dark green line down the middle of the back and antennae that are as long or longer than their body. Their reproductive capacity is very high. All individuals are female and mature in five to seven days in warm weather, producing several offspring per day for up to two weeks. While feeding, greenbugs inject saliva that is very toxic to sorghum, destroying chlorophyll in the leaves and turning them a red or rusty brown. As host plants deteriorate, winged forms develop that are capable of wind-assisted dispersal over great distances. Greenbug damage to sorghum in Kansas has declined in recent years, but could resurge at any time. Injury may occur at any time during the growing season, from seedling through soft dough stages. Empty panicles can result from flower steriilty induced by greenbug feeding.