The cotton aphid, Aphis gossypii Glover, is the most common and the only aphid species of economic importance attacking cotton in the United States. Aphids occur in most cotton fields every year but only occasionally cause economic damage. In general natural enemies keep aphids under control but the use of insecticides for other cotton pests can reduce populations of important predators and parasites and the aphid population will flare. Other factors may play a role in flaring the population but regardless, the pest’s prolific reproductive capacity can very rapidly lead to severe infestations.
Aphids feed by sucking sap from phloem tissue of the cotton plant secreting the excessive sugars in the form of honeydew. Heavily infested leaves will often curl downward along their edges. The accumulation of honeydew will cause leaf surfaces to appear shiny and to become sticky. Often a black sooty mold will grow on the honeydew turning the leaves black. Severe infestations can seriously stunt plants and reduce yields, particularly if populations persist for a long period of time. Honeydew secretions on open bolls may result in lint staining or “sticky cotton.”