Rose curculio (Merhynchites bicolor)
What do rose curculios look like
If you grow roses, be on the lookout for these beetles with red or black bodies and black heads with a long snout. The beetles measure about ¼ inch long.
The miniscule eggs are difficult to spot hidden in the buds and hips. Pudgy, creamy white larvae hatch and feed on the buds and hips before dropping to the ground and pupating. They seem to prefer light-colored roses and can be found in most of the United States and in southern Canada.
Damage caused by rose curculios
The larvae pupate in spring, climb up the roses as adults and feed on the buds and flowers, puncturing them with their snouts and causing small holes throughout. They'll cause your rose petals to have holey, marred petals and drooping buds. You’ll notice the damage in late spring and early summer.
How to control rose curculios
Act quickly if you see rose curculios because they can quickly ruin a rose bush in one season. Hand picking and disposing of adults is actually quite effective. Pick them off and drop into a bowl of soapy water, or shake the canes over the bowl to remove the beetles.
Because the larvae drop to the ground, you can also fight the infestation by releasing parasitic nematodes into the soil. They’ll devour the larvae. If a cultivar is repeatedly infested year after year, you might consider replacing it with a darker-flowered variety.
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