Aphids are slow-moving, soft-bodied insects. Adult cotton aphids are approximately 1/10 of an inch long and roughly pear shaped. They may possess wings or may be wingless. Cotton aphids have two color phases: yellowish or dark green.

The cotton aphid has two projections which arise from the upper side of the abdomen. These small tubes are called cornicles and are used to excrete defensive secretions.

Both the adult and immature stages (called nymphs) of the cotton aphid have stylet like mouthparts, which they use to suck juices from the host plant. Consequently, cotton aphids are sometimes referred to as plant lice

FIG:cotton Aphid


The cotton aphid, Aphis gossypii, excretes honeydew rich in melezitose (ca. 30–40%). Their droplets (inset, 50X) tend to be larger than those produced by whiteflies.

FIG: Whitefly


Whiteflies, Bemisia spp., also excrete honeydew, but as trehalulose-rich (ca. 40–50%) droplets (inset, 50X).