Cherry slugs, or pear slugs, are small black worms that belong to the sawfly family of insects. They eat the leaves of cherry trees from mid- to late summer and eventually become non-stinging wasps.
Cherry slugs are small dark green to black worms that chew through cherry tree leaves. A mature cherry slug can reach up to 1/2 inch long, and its head is a bulge on one end. Younger cherry slugs are much darker in colour.
Cherry slugs eat cherry leaves for a living. They do not often chew through the leaf. Rather, they eat the upper leaf surface and leave behind a trail of brown spots. If the leaf is heavily damaged, it will fall off.
Tree owners can get rid of cherry slugs by blasting a strong jet of water to knock them off the leaf. Pesticides that contain carbaryl or malathion are also effective.