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Beginner

Scientific Name: Oberea perspicillata (previously O.bimaculata) (Order: Coleoptera; Family: Cerambycidae)

Identification

• Damage is present as two rings, spaced approximately 20 to 30 mm apart, 10 to 20 cm below the tip of affected primocane, made of zipper-like puncture wounds.
• Damaged shoot tips bend over, wilt and ultimately die above the point of injury.
• Adults are black, slender beetles approximately 12.5 mm in length.
• Upper surface of the prothorax is yellow to bright orange with two or three black dots.
• Antennae are very long, up to the entire length of their body.

Often Confused With
Phytophthora Crown and Root Rot
Fireblight
Raspberry Crown Borer
Red-necked Cane Borer

Period of Activity
The beetles are active in June, July and August. They overwinter near the base of the cane, pupate in the spring, and emerge as adults in the summer. Primocanes wilt immediately after egg-laying occurs.

Scouting Notes
Look for bent-over primocane shoots. If the two characteristic zipper-like girdling marks are observed approximately 15 cm below the shoot tip, the problem is likely raspberry cane borer. Adult cane borers are rarely observed.

Thresholds
None established.

 

Advanced

Scientific Name: Oberea perspicillata (previously O.bimaculata) (Order: Coleoptera; Family: Cerambycidae)

Identification
Raspberry cane borers lay eggs in the raspberry cane, causing primocane tips to wilt and die back. The hallmark of raspberry cane borer damage is the presence of two rings made of zipper-like puncture wounds created by the female beetle. The two rings are spaced approximately 20 to 30 mm apart and occur 10 to 20 cm below the tip of the affected primocane. The egg is placed between the two rings and tends to be located closer to the lower one. This damage to primocane tissues causes the shoot to bend over, wilt and ultimately die above the point of injury.

Raspberry cane borer adults are black, slender beetles approximately 12.5 mm in length. Their pronotum, or upper surface of the prothorax, is yellow to bright orange with two or three black dots. The antennae are very long measuring as much as their entire body length.

Often Confused With

Phytophthora Crown and Root Rot
Caused by a fungus and associated with high moisture around the roots. If wilted canes are discoloured at the base, the problem is often phytophthora. Scrape the surface of the bark in the crown area and look for a reddish-brown discolouration of the underlying tissue, typical of this disease. .

Fireblight
Fireblight is caused by bacteria and starts out as a blackening of the leaf veins. The tip of primocanes bends over to the form of a shepherd’s crook and the entire cane can be affected, wilt and die. Amber coloured ooze or flakes of whitish dried exudate are sometimes evident.

Raspberry Crown Borer
The entire plant becomes weak and lacks vigour. No zipper-like marks are observed near the primocane tip and instead a larva can be observed inside the crown.

Red-necked cane borer
The two insects are both beetles with orange or reddish colouring in the thorax. Raspberry cane borers have antennae which are as long as their body, approximately 12.5 mm long. Red-necked cane borers have short antennae, and are smaller in size, approximately 6 mm long. The two beetles also damage primocanes in different ways. Raspberry cane borers produce two zipper-like girdles near the tip of the cane, which cause the shoot tip to bend over, while red-necked cane borer larvae cause swellings on the lower portion of the cane.

Biology
The raspberry cane borer adults are active in early June. Females lay single eggs into the pith of primocanes, close to the tip. Once the larvae hatch they begin tunnelling down the cane. The larvae are creamy-white and legless. They have a brown, rounded head and measure approximately 20 mm in length when fully grown.

There remains some confusion as to the duration of the cane borer life cycle. According to some accounts (Ellis et al. 1991), the raspberry cane borer has a two-year life cycle. The larvae hatch and begin feeding on the pith of the primocane while boring down. They then overwinter inside the cane, potentially near the lower ring of cane punctures, and spend the next year tunnelling further down into the crown where they will feed on the crown tissue. They spend their second winter in the crown and pupate in the spring to emerge as adults between June and August. According to another account (Mid-Atlantic Berry Guide), the cane borer has a one-year life cycle, whereby the larvae feed on cane tissue and bore down the cane to reach the base in the fall. They overwinter near the base of the cane, pupate in the spring, and emerge as adults in the summer.

Period of Activity
The beetles are active in June, July and August. Primocanes wilt immediately after egg-laying occurs.

Scouting Notes
Look for bent-over primocane shoots. If the two characteristic zipper-like girdling marks are observed approximately 15 cm below the shoot tip, the problem is likely raspberry cane borer. Adult cane borers are rarely observed.

Thresholds
None established.

Management Notes

• Examine canes frequently in June and July for injury.
• Cut any affected primocane tips about 2 cm below the lower girdle, as soon as possible after injury occurs.
• Check if the cane below this point shows tunnelling damage as that would indicate that the larva has hatched and moved further down. Cut down further until no more damage is observed.
• Remove and destroy all prunings to kill the insects inside.
• If there is a history of significant damage from this pest, consider the use of a registered insecticide when beetles are first active. See OMAFRA Publication 360: Fruit Crop Protection Guide (Chapter 3: Berry Crops).