Detailed Guide to Identifying and Controlling the Green Peach Aphid

The green peach aphid causes extremely widespread damage. Adults and nymphs gather in groups on the undersides of leaves and on tender shoots to suck sap. Infested leaves curl irregularly toward the underside, which affects the growth of new shoots on peach trees and spreads viruses. The green peach aphid can damage more than 300 species of plants, making it one of the most difficult pests to control.

Winged viviparous females are green or yellow-green; brown and reddish-brown forms also occur, with colors varying according to the host; wingless viviparous females are green, yellow-green, apricot-yellow, and reddish-brown; nymphs are small and pale red; eggs are mostly laid in the crevices of the host's shoot tips, bud axils, and small branch forks, and are oblong and jet black. It produces more than 10 to more than 20 generations a year. Eggs overwinter in the shoot tips, bud axils, small branch forks, and bark crevices of peach trees. From the bud-swelling stage to the flowering stage of peach, the overwintering eggs hatch, and nymphs begin to damage peach buds. By late April, when new shoots have grown 1-3 cm, temperatures rise and the aphids develop rapidly. From late May to early June, they reach their peak. After that, winged aphids appear in large numbers. After mid-June, winged aphids migrate to summer hosts to cause damage. In mid-October, winged aphids are produced again and migrate back to peach trees, where they mate and lay eggs to overwinter.

Control methods:

1. Use natural enemies to control aphids, such as ladybugs, green lacewings, and parasitic wasps, but aphids reproduce quickly and in large numbers, so relying on natural enemies alone is not easy to control.

2. For chemical control, insecticides such as pymetrozine, acetamiprid, and pirimicarb can be selected for spray control. Note that spraying should be fine, thorough, and even to achieve good results.