The pear aphid (Dysaphis pyri) is a highly damaging pest of pear orchards. Both nymphs and adults feed on developing foliage, causing leaves to curl and distort while reducing tree vigor. Heavy infestations can affect shoot development, trigger premature leaf fall, and compromise overall orchard productivity. Aphids also excrete honeydew, creating a sticky layer on leaves and fruit which promotes the growth of sooty mold.
Pear aphids are most damaging during spring and early summer when young leaves and shoots are actively growing. Early detection and timely intervention are essential to prevent populations from reaching damaging levels.
Pear aphid infestations can cause a range of symptoms, including:
The aphids overwinter as small, black eggs deposited in bark crevices and near buds.
Eggs hatch shortly before bud break. Wingless females colonize young leaves and reproduce rapidly without mating, allowing populations to increase quickly.
Several generations develop through spring and early summer. As colonies expand, feeding causes characteristic leaf curling that protects aphids from natural enemies and challenging weather conditions.
By mid-summer, colonies on pear naturally decline as winged adults develop. These adult aphids migrate to their secondary host plants. In autumn, they return to pear trees to reproduce sexually and lay fertilized overwintering eggs around buds and young twigs, completing the annual life cycle.
Regular monitoring is essential during spring, before leaves become fully curled. Inspect orchards from bud break onwards for:
Monitoring early in the season helps identify infestations before leaves become tightly curled and more difficult to manage.
Biological control is an effective and sustainable way to manage pear aphid populations. Koppert offers a range of natural enemies, including parasitic wasps, lacewings, hoverflies, ladybirds, and predatory midges. By establishing beneficial insects early, growers can suppress aphid populations naturally and reduce reliance on conventional insecticides.
