Pest profile

Melon aphid (cotton aphid)

Aphis gossypii · Hemiptera: Aphididae[2]

Melon aphids curl and yellow the leaves of cucurbits, citrus and hibiscus and can spread several plant viruses.[1]

Melon aphids in yellow and dark green forms on a stem, tended by an ant, beside a 1 mm scale bar
Melon aphids in yellow and dark green forms on a stem, tended by an ant, beside a 1 mm scale bar. Photo: Jesse Rorabaugh, public domain (CC0), via iNaturalist

How to identify it

  • Wingless females are 1 to 2 mm long, usually light green mottled with dark green, with black cornicles.[1]
  • Winged females have a black head and thorax and a yellowish-green abdomen.[1]

Look-alikes

Look-alikeHow to tell them apart
Spirea aphidIts tail-like cauda is dark brown to black; the melon aphid's is pale to dusky.[1]

Where it lives

It occurs in tropical and temperate regions worldwide; in the U.S. it's a regular pest in the Southeast and Southwest.[1]

US map: public records from 25 states since 1990 (GBIF).

Biology and life cycle

In the South, females keep producing young without mating as long as weather allows, and hot weather doesn't slow them.[1]

A generation can take as little as about a week, so numbers climb fast.[1]

Damage and signs

  • Feeding curls and distorts leaves, and the honeydew grows sooty mold on fruit and foliage.[1]
  • Hosts include watermelon, cucumber, cantaloupe, squash, pepper, citrus, cotton and hibiscus.[1]

Health risk

It feeds on plants; UF/IFAS mentions no risk to people.[1]

Control

Prevention

Row covers and reflective silver or white mulches reduce aphid numbers.[1]

Biological control

Lady beetles, flower flies and braconid wasps attack it; the wasp Lysiphlebus testaceipes can parasitize up to 99%.[1]

Pesticides

If spraying, cover foliage thoroughly and avoid unneeded insecticides; resistance to pyrethroids and organophosphates is widespread.[1]

Common questions

What are the tiny aphids curling my cucumber leaves?
Often melon aphids, a serious pest of cucumbers and melons.[1]
Why did aphids get worse after I sprayed?
Insecticides for other pests can kill beneficial insects and trigger melon aphid outbreaks.[1]

Sources

  1. University of Florida IFAS Extension (Featured Creatures), “Melon Aphid or Cotton Aphid, Aphis gossypii (EENY-173).” edis.ifas.ufl.edu/publication/IN330 (accessed 2026-10-06)
  2. iNaturalist, “Aphis gossypii taxon page (order and family).” www.inaturalist.org/taxa/309466 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.