During a quick walk-through in early February, I found melon aphids on hibiscus, green peach aphids in high numbers on English daisy and, in a different overwintering structure, a mixed population of green peach and melon aphids on two dozen containerized gum trees. Both species are major pests of ornamental plants. They are easily distinguished by the color of the cornicles, a pair of tube-like projections, on the distal end of the abdomen, from which the honeydew is excreted. The adult green peach aphid is light to dark green or pink, with red eyes. Three dark lines run down its back.
Winged adults mingle with wingless forms on the same plant.
Shiny, black eggs are laid only in the northern United States. This method of reproduction results in the potential for very rapid population increases. The green peach aphid's resistance to many pesticides, coupled with its reproductive potential makes it a formidable pest on greenhouse crops and bedding plants. The wingless nymph resembles the larger adult. The GPA has a broad host range, having been collected from more than 100 species, including a variety of vegetable and ornamental crops.