It overwinters in the larval stage in the cane, emerging as the adult moth the following spring. Red currants are attacked most frequently. Cut out and destroy infested canes as early as possible. Diazinon applied in June will control adults and young larvae before they enter canes. Once the larvae bore into canes, chemical control is not possible.
Foliage is consumed by several small, spotted, caterpillar-like larvae.
The adults are sawflies about the size of a housefly. Two generations hatch each year, causing damage in the spring and again in late summer. Diazinon or malathion will control this insect. Start looking for damage shortly after the leaves have fully expanded. The second generation usually is less severe than the first and does not require treatment.