| Life Cycle: | The adult raspberry crown borer appears more like a yellow jacket wasp than a moth. Moths begin emerging in late July and can be seen on bramble canes into September. Like the raspberry cane borer its life cycle is two years. The female, which lives for less than 2 weeks, begins ovipositing eggs upon emergence. She will lay 2-3 reddish-brown eggs on the underside of leaves and can lay approximately 100 over her life. The eggs will hatch from September until November. The larvae will migrate down the cane to the soil where they will burrow into the base of the cane or surrounding bark and form a hibernaculum to overwinter. In the spring the larvae will bore into the crown and feed while it matures. The larva will grow to be up to 3.5 cm over the next winter and spring. In mid-summer of the second year, the mature larvae will pupate for 2-3 weeks. |
| Host: | Raspberries and blackberries are the preferred host although all members of the genus Rubus will be attacked. |
| Bio Region: | Throughout North America. |
| Damage: | The crown borer will drill a hole into the cane at the base. Wilting of the cane ensues. Damage is most prevalent in the second year. |
| Management: | There are few measures that can be taken once a cane field is infested and infestation is only visually apparent after the damage has been done. This means that prevention is the best defence. The purchase of registered disease free canes is highly desireable. Removal of wild brambles in the vicinity of the commercial field is also recommended. The underside of leaves should be inspected from August onward for eggs. Upon any signs of cane wilt, the base of the cane should be inspected for entry holes. There may also be a trail of frass (sawdust-like fecal matter). The infested cane should be pulled and burned. |
| Controls: | There are no approved controls for raspberry crown borers. |
