Rosy Apple Aphid

D. plantaginea Passerini (Hemiptera, Aphidae), is a major pest of apple in North America and Europe, causing leaf curling though sap feeding on buds, fruits or leaf undersides, and the secretion
of plant hormone-mimicking compounds in the aphid’s saliva. In addition, honeydew produced by the aphids provides a media for the growth of a sooty mold fungus which can affect the fruit finish. It is feared by fruit growers as it causes substantial damage to the fruits at low densities, that escape monitoring efforts.

The life cycle of D. plantaginea is holocyclic. Aphids overwinter as eggs on the bark of apple trees, its primary host. Egg hatch coincides with apple bud break in early spring, giving rise to the first generation of wingless females, known as fundatrices. The fundatrices are giving birth to live nymphs without mating (parthenogenesis). As the season progresses, several generations of wingless females are produced, which results in an enormous reproductive potential.

In late spring and early summer, some of the aphids develop wings and migrate to secondary host plants, such as plantain (Plantago spp.). Here, they continue to reproduce asexually. In the autumn, winged males and females are produced, which return to the apple trees to mate and lay eggs, completing the cycle.

Due to the extremely low economical threshold in the early season, the rosy apple aphid is a difficult pest to control in all but the first few generations because of the protection provided by the tightly curled leaves in which it feeds. Currently, the most widely used strategy to control the rosy apple aphid is the elimination of fundatrices. Chemical control must be applied before the formation of curled leaves. Effective management of D. plantaginea usually involves an integrated approach that combines cultural, biological, and chemical control methods.