Like many organisms, when you dive deep enough, it has some interesting characteristics. This aphid is an omnivorous plant sucker, feeding on sap of plants in the dogbane family such as milkweed, vinca and oleander. It will even cross over for dessert on crassulaceae (succulents such as jade plant) and solanaceae (nightshade family).
All oleander aphids are female as males do not occur in the wild. They are parthenogenetic (reproduce without male fertilization) and viviparous, giving birth to live nymphs instead of laying eggs. The nymphs go through five stages all looking similar to the adult. Some adults will develop wings when there is overcrowding or the plants are dying off, allowing the aphid to establish a new distant colony.
|Winged A. nerii - Ken Schneider|
So what does eat these aphids? Hover or flower flies, lacewings and lady beetles have no problem with their secretions. A prominent source of predation are the aphid wasps such as Lysiphlebus testaceipes. They lay their eggs on the aphid nymphs and the resulting larva enters the aphid which mummifies while the larva matures inside.
The oleander aphid can become a garden pest, injuring young shoots and producing a sticky honeydew which can develop a black sooty mold on it, not what you want on your garden flowers. The aphids can be removed by hand and are vulnerable to insecticidal soaps and oil. Gardeners should avoid other insecticides as they are also toxic to butterflies and other pollinators.
|Large Milkweed Bug- Mark Bower|
|Photo- Mark Bower|
|Large Milkweed Bug adult and nymphs- Photo by Greg Hume|
Details on the aphid are found at this University of Florida website.