Plum gall midge

The Plum gall midge (Latin: Asphondylia pruniperda) is a small insect belonging to the order Diptera and the family Cecidomyiidae. This pest specifically targets stone fruit crops, particularly those of the genus Prunus, and can cause significant damage to yields in both home gardens and commercial orchards.

The primary crops affected by this pest include the common plum, cherry plum, and blackthorn. In certain cases, the midge may also infest other fruit trees within the Rosaceae family if they are grown in close proximity to the primary breeding sites of the insect.

The biology of the species is characterized by larvae developing within the plant tissues. Adults lay eggs inside young ovaries or buds. Upon hatching, the larvae feed on plant sap, inducing the formation of characteristic tissue growths known as galls. The lifecycle typically involves one generation per year, with the pest mainly overwintering as a larva inside damaged fruit or within the soil.

Damage symptoms manifest as the deformation of fruit and premature fruit drop. Affected ovaries cease to grow, turn yellow, and eventually shrivel. The harmful impact of the midge extends beyond direct crop loss to the weakening of flower buds, which reduces the tree's overall yield potential for the subsequent growing season.

Protection strategies involve a comprehensive approach: agrotechnical methods consist of the regular collection and proper disposal of fallen fruit containing larvae, as well as deep autumn tillage around the tree trunk to destroy pupae. Chemical control includes spraying with insecticides during the period of adult flight or at the fruit set stage, in accordance with local pesticide application regulations.