Authors: Dr. Randy Hudson, Dr. David Adams, University of Georgia, Department of Entomology.
Melon aphids are soft-bodied, pear-shaped, and pale- to dark-green in cool seasons (spring) and yellow in hot, dry summers. Though winged forms develop periodically, most adults are wingless and about 2.0 mm long. All forms have a pair of tailpipe-like appendages known as cornicles. Nymphs are smaller than the wingless adult but similar in shape and color.
The melon aphid has a wide host range. They have been found on all the cucurbits, bean, pea, eggplant, okra, spinach, tomato and cotton. There are certainly other hosts not reported.
Congregating on lower leaf surfaces, they pierce the plant and suck sap. Leaves curl downward and pucker. Wilting and discoloration may follow. Aphids secrete honeydew, the plants become sticky, and sooty mold develops. Sooty mold can reduce light penetration, subsequently reducing yield and quality.
Adults pass the winter on greens and other wild hosts. Winged forms migrate to other hosts in late spring. During these migratory flights, aphids may spread viral diseases from infected volunteer plants and weeds to healthy crops. In Georgia, the aphids are nearly all females. Successive generations of females, mainly wingless, are produced throughout the year. Winged migrants develop whenever overcrowding occurs or food becomes scarce. Many generations may occur per year.
In many crops, natural controls often can regulate the population below economic impact thresholds. Many predators, fungal diseases, high temperatures, hard rains and damp weather reduce aphid populations. Insecticides are the second choice for controlling aphids.