Notes on Raspberry Insects
Red-necked cane borer
Identification
This pest, also known as the rose-stem girdler, is seen occasionally
in raspberries in Ontario. The adult beetle is a small (6 mm) dark metallic
beetle with a flat head and reddish coloured band just behind the head.
The beetle emerges from fruiting canes in late spring or early summer.
Eggs are laid on the lower half of the primocanes. Larvae tunnel in a
spiral fashion around the cane. The first few spirals under the bark result
in a swelling or gall. The larvae continue to tunnel up or down the cane
in the pith. Infested canes may wilt or dry up and often break off at
the gall.
Red-necked cane borer larvae
Period of Activity
Adults are active in late June and early July. Larvae tunnel up and down
the cane in July and August. Injury is most frequently observed in late
summer, fall or winter when infested canes break off about two to three
feet above the ground.
Management notes
There are no insecticides registered for control of this pest. Prune
out and remove infested canes before spring.
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