Oleander Aphid, Aphis nerii

	Oleander aphid Aphis nerii Hemiptera: Aphididae Orange County, CA © Peter J. Bryant. Text © Britton Jacob-Schram Back to Arthropods of Orange County, California Back to Hemiptera index page
The Oleander aphid is a bright yellow insect with black legs, and stalks known as cornicles on the back of the abdomen. It is commonly found on oleander, butterfly weed and milkweed, appearing on buds, new shoots and foliage in the spring. Large colonies often develop over the summer and may cause injury or death of the host plant. Like other aphids the Oleander aphid secretes a viscous sugary substance known as honeydew. This secretion is greedily sought after by other insects, especially ants. Some ants live in close proximity to, and tend to aphids. As honeydew accumulates on the leaves, a black sooty mold often follows and can be unsightly.
	Wingless female giving birth The Oleander aphid reproduces entirely by parthenogenesis (without fertilization). Both winged and wingless females reproduce this way so, at least in the wild, no male Oleander aphids occur. The females are also viviparous, meaning that they do not produce eggs but instead give birth to live young called nymphs, the adult female's clones.
	Nymph
	Molting
	Nymph with wing buds
	Winged female Aphids are polymorphic – they have different body forms under different circumstances. Adults can be wingless (apterous) or winged (alate). Winged adult females are usually only seen when the host plant is no longer viable, or when a colony becomes overcrowded to the point where migration to other host plants must occur.
	Mummy Many Oleander aphids are attacked by the parasitic wasp, Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae). The wasp lays its egg by inserting its ovipositor within the aphid nymph; the wasp larva then utilizes the aphid’s internal organs as its food source. After the parasite goes through metamorphosis and becomes a wasp inside the body of the aphid, it cuts a hole in the back of the aphid’s abdomen and emerges, leaving the aphid’s empty body, referred to as a “mummy”, as a hollowed-out dry shell with an open door in its back.
Learn more! Borror, Donald J. & Richard E. White. A Field Guide to Insects: America North of Mexico. New York: Houghton Mifflin Co. , 1970. *Species Aphis nerii* - Oleander Aphid** Oleander Aphid. Featured Creatures, Dept. of Entomology and Nematology, University of Florida

On milkweed. Fullerton Arboretum, Fullerton, Orange County, CA. 12-31-06. © Ron Hemberger	On milkweed. Fullerton Arboretum, Fullerton, Orange County, CA. 12-31-06. © Ron Hemberger
On milkweed. Fullerton Arboretum, Fullerton, Orange County, CA. 12-31-06. © Ron Hemberger	On milkweed. Fullerton Arboretum, Fullerton, Orange County, CA. 12-31-06. © Ron Hemberger
Fullerton Arboretum, Fullerton, Orange County, CA. 1-6-07. © Ron Hemberger	Fullerton Arboretum, Fullerton, Orange County, CA. 12-09-09. © Ron Hemberger