Fig. 50: Green Peach Aphid, Myzus persicae (Sulzer); Aphididae, HOMOPTERA
Also the closely related tobacco aphid, Myzus nicotianae (Blackman); Aphididae, HOMOPTERA
A, Winged adult.
B, Wingless adult.
C, nymph with wing buds.
The tobacco aphid probably overwinters on weed hosts or on cole crops that remain alive through the winter. Tobacco aphids are not known to have an egg stage, and they reproduce by giving birth to live young female aphids without mating. Their young are able to produce young as well without mating. If the plant becomes too crowded or if it becomes late in the season and the aphids need to find a winter host, the aphids give birth to young that will grow up to have wings and can move to other plants. Differences on reproductive rates exist between the red and green forms of the tobacco aphids. The red form is able to reproduce much faster during extremely hot weather than the green form.
On chrysanthemums, green peach aphids feed on all parts of the plant (melon aphids feed only on the buds and leaves, and chrysanthemum aphids feed only on the stems and leaves). Green peach aphids will not become established in the presence of the other two aphids unless pesticides are applied. In that case, green peach aphids outlive both melon aphids and chrysanthemum aphids.
Because green peach aphids overwinter on weed hosts, infestations can occur in the greenhouse any time of year. Green peach aphids readily infest bedding plants and can be introduced into greenhouses whenever bedding plants are brought in from another grower. Although damage per aphid is often not serious, these aphids reproduce so rapidly that serious harm can be done in a short time. Moreover, these aphids' resistance to pesticides calls for thorough applications whenever a new infestation is found. Tobacco aphids can be controlled in the same manner as green peach aphids. For specific chemical controls, see your county Extension agent or consult your state's pest management guide for the control of pests of ornamental plants.