**Raspberry Cane Borers** (*Oberea bimaculata*) are slender, long-horned beetles that are specialist pests of plants in the *Rubus* genus, primarily raspberries and blackberries. The conflict is **cane dieback and loss of fruit production**: the adult female damages the tip of new canes by creating two parallel rows of punctures (a **double girdle**) and laying an egg between them. The larva then hatches and tunnels down the pith of the cane over two years, causing the tip to wilt and the cane to eventually die.
Taxonomy and Classification
Raspberry Cane Borers belong to the Family Cerambycidae (Longhorned Beetles). They undergo complete metamorphosis, with the damaging stage being the larva.
Physical Description
Adults are 12-15\text{ mm} long.
- **Adult (Key ID):** Slender, black body; the thorax is often orange or yellow and features two or three black spots.
- **Larva (Key ID):** Creamy-white, legless larva found tunneling inside the cane pith.
- **Damage ID:** A characteristic **double ring of punctures/girdles** near the cane tip, followed by wilting of the cane tip.
- **Conflict:** Agricultural.
Distribution and Habitat
Found primarily in eastern North America. Habitat is the canes of cultivated and wild raspberries, blackberries, and related brambles.
Behavior and Conflict
The conflict is the result of the egg-laying ritual.
- **Girdling:** The female girdles the cane tip to kill the tissue, preventing sap flow to the tip, which may protect the egg from rapid growth and crushing.
- **Slow Damage:** The long, two-year life cycle means that damage accumulates over multiple seasons, weakening the entire plant system.
Management and Prevention
Management is **Pruning and Destruction**.
- **Immediate removal and destruction** of any cane tip showing the wilting and the characteristic double girdle (cut 6-8 inches below the lowest puncture).
- Removing and destroying old, dead canes where the beetle may be pupating.
- Infrequently used, as the larva is protected inside the cane; chemical sprays are timed to control the short-lived adult stage before egg laying.
Conservation and Research
Research focuses on developing monitoring programs (e.g., traps) for the adult beetles to better time cultural or chemical controls.