Green Peach Aphid
Egg - Eggs are first green but later turn shiny black. However, the egg stage is not known in North Carolina.
Nymph - Nymphs are green and resemble adults but lack wings.
Host Plants - The green peach aphid is a pest of a wide range of plants, including tobacco, vegetables, deciduous fruits, flowering plants, and ornamental shrubs.
Damage - The green peach aphid is an important pest of tobacco in most of the tobacco-growing regions of the U.S. It is a particularly important pest in the Georgia and Florida shade-grown tobacco belt and in Connecticut. In the southern U.S., the green peach aphid attacks tobacco throughout the growing season, but in Maryland and Kentucky, aphid attacks usually occur in late-season tobacco. Although the green peach aphid occurred on tobacco in North Carolina for many years, it was not reported to be a serious pest until 1946. Severe infestations also occurred in 1947, 1948, and again in 1976 through 1979.
In North Carolina, the green peach aphid attacks tobacco in both plant beds and in the field. Aphids damage tobacco plants by sucking the sap from the leaves. Such feeding weakens plants, causing curled, stunted, distorted leaves. They also contaminate the leaves with cast skins and honeydew in which a black sooty mold fungus develops. Such leaves cure poorly and are low in quality. The green peach aphid also transmits viral plant diseases such as tobacco etch and potato virus Y (PVY).
Life History - In southern states the aphids are nearly all females. These adult females give birth to living nymphs. Most of the nymphs develop into green, wingless adults which in turn produce another generation of wingless females. The adults and nymphs of the wingless form look alike. Other nymphs develop into blackish, winged adults. There is no egg stage in North Carolina. Successive generations of females, mainly wingless, are produced throughout the year. This pattern of development occurs as far north as Tennessee and Maryland. In fall, winter, and early spring, host plants include cabbage, collard, turnip, wild mustard, and dock. In spring, winged aphids fly to tobacco.
In cold northern climates, a generation of males and egg-laying females develop in the fall. Eggs are laid on certain fruit trees where they overwinter. Eggs hatch in spring, and the second or third generation of aphids infests tobacco. Aphids first appear in the plant beds. Once in the field, aphid populations may increase rapidly and cause serious damage before growers are aware of a problem. Numbers generally decline after plants have flowered, but can remain high on sucker growth.
A number of insecticides are available to control aphids on tobacco. When 25 percent or more of the plants are moderately infested (100 or so aphids on each of two or more leaves), chemical control is warranted. Repeated applications of certain carbamate insecticides within intervals of a week or less are frequently conducive to aphid buildups. For specific chemical recommendations, consult the current North Carolina Agricultural Chemicals Manual.