Cane Borer - Red-Necked

Adult Cane Borer are elongated and cylindrical. Elytra vary from beautiful velvety black to blue with bluish reflection. It has a red neck from which it gets its name. The head is small, dark, bronze, and deeply grooved. Eggs are irregularly oval and flattened, dirty white and have brownish edges. Larva are elongated and flattened. They are white to pale yellowish with brown head, measure 16 to 19 mm long. In northern regions, they emerge from June until August. Eggs are inserted in the bark near leaf bases and hatch in about 3 weeks.

Larva feed beneath the bark and proceed spirally upward or downward in the wood parts causing the stems to swell and become gall-like. Later, larvae bore into the pith and continue upward or downward for 10 to 20 cm or more, sometimes causing stems to break.

Mature larvae form oval pupal cells in the pith where they overwinter. Pupal cells typically are only a short distance above the ground and a few centimeters below the first gall. Pupation occurs during April and May and lasts 7 to 10 days. Adults exit through D-shaped emergence holes. This cane borer has one generation annually.

These pest usually affects rasberry and blackberry plants in gardens and in the wild.

© Copyright Photo by Vincent J. Hickey.

For control products and more information please see our Borer Control page.