Rose Curculio - Merhynchites bicolor

Rose Curculio damage to rose Adult, 1/4 inch, on rose buds
Baldo Villegas - sactorose@yahoo.com

HOSTS: Roses.

DESCRIPTION: Common in cooler regions. Adults are 1/4 inch long, black to red beetles with a black snout. They injure buds, preventing them from opening, and riddle flowers that do succeed in opening with holes. Adults may also kill the tips of new shoots.

LIFE CYCLE: Larvae overwinter in the soil near rose bushes. Adult emerges in spring and lays eggs on flower buds. Larvae hatch and feed on flowers.

CONTROLS:
Cultural: Pick off adults.
Biological: Parasitic nematodes may help to control larvae before they emerge in the spring. Fall application is best in Western Montana.

Botanical: Neem can be sprayed on larvae feeding on flowers.


Missoula County Extension Office; Missoula, Montana 59808 - Updated for 2006