Chokeberry Gall Midge – Contarinia virginianae

Chokeberry Gall Midge: Appearance, Territory, Damage and Life Cycle Latin Name: Contarinia Virginianiae Appearance: The gall is a pear-shaped, hollow enlargement of the fruit. On the same fruit cluster, there may be a mix of regular berries and galls. The gall is initially green in appearance, but as it matures, it turns red. The primary core of the body, which is orange, seems to be encased in a transparent envelope. Host Plant: Adults emerge from pupation in May, and lay eggs in the flowers and developing fruits of host plants. This insect feeds on chokecherry and saskatoon berry. Territory: It is found throughout the Prairie Provinces. Damage Caused: The chokecherry fruit gall midge is a small insect that damages the fruit directly. Galls form as a result of the larvae feeding. The gall is a pear-shaped, hollow enlargement of the fruit. On the same fruit cluster, there may be a mix of regular berries and galls. The gall is initially green in appearance, but as it matures, it turns red. Chokecherry gall midge causes chokecherry damage. Chokecherry fruit that is still forming gets distorted by the larvae, causing it to expand and become hollow. Bright orange-red maggots grow and feed within this galled fruit. Life Cycle and habits: The pupal stage is spent near the base of previously afflicted chokecherries during the winter. Females deposit eggs in the flowers when adults emerge in early spring, around the time of flowering. The juvenile maggots burrow into the growing chokecherry fruit when the eggs hatch, causing it to become larger and hollow. Many maggots may congregate in one area, and maggots will feast on the growing fruit until midsummer. Feeding causes the fruit to swell and darken, resulting in a bloated gall, causing the developing seeds to abort. Larvae eat inside the gall until late July, when they emerge to pupate on the ground. Before the berries are fully mature, the hollow fruit will fall from the vine. They descend to the ground and pupate once they’ve done feeding. Every year, a new generation is born.