Several species of aphids or plant lice feed on tobacco, but only the tobacco aphid commonly builds up large colonies. Winged aphids fly to plants in the bed or field and being producing wingless young (nymphs). Wingless, aphids are softbodied, pink to red, pale green to yellow-green, pear-shaped, and only about 1/16 inch long when full grown. Most aphids are wingless even as adults, but darker, winged forms may also be produced. Aphids have beak-like mouthparts through which they suck plant juices. In addition, they produce a sticky waste product, honeydew, on which sooty mold develop. As a result of these factors, both yield and quality may be reduced. (This and other species of aphids may also transmit certain virus diseases.) Infestations are characterized by the presence of aphids (mostly on the underside of upper leaves), shiny or greasy honeydew deposits on the upper surface of leaves, and sooty mold. In recent years, the red (pink) form of the tobacco aphid has become much more prevalent than the green form.