The rose chafer (Macrodactylus subspinosus) is a tan-colored beetle that attacks and feeds on rose bushes and other fragrant flower species during the summer. If you find this pesky bug nibbling away at your prized ornamental shrubs, you have several methods at your disposal for ridding your garden of this nuisance pest.
First, pull on a pair of garden gloves to protect your hands. Then, inspect your rose bush or ornamental shrub in the early morning – the cooler temperatures means this insect is more likely to be sluggish and not flying, reports the Alabama A&M Extension – and pluck the rose chafers off of the shrub’s branches or leaves by hand. The University of Minnesota Extension reports that this is one of the best options for isolated infestations of this beetle.
Next, step on the rose chafer beetles you’ve removed to crush and kill them, suggests the University of Wisconsin Extension. Alternatively, the University of Minnesota Extension recommends that you drop the beetles into a bucket of soapy water. To effectively kill the beetles with soapy water, combine 5 tablespoons of standard dish detergent in 1 gallon of water.
If you prefer a more hands-off approach to controlling this garden pest, try a bug spray. Spray your rose bush or ornamental shrub with an insecticide if manual hand-picking doesn’t sufficiently control this insect problem. Use any standard insecticide formulated with bifenthrin, imidacloprid or permethrin, as these chemicals will sufficienttly kill rose chafers. Apply the insecticide according to its manufacturer-specific guidelines, since toxicity varies widely by product, warns the Alabama A&M Extension.
Remember, rose chafers must physically be present on the shrub when you spray the shrub with insecticide. Apply the insecticide according to its labeled guidelines in the early morning when beetles move slower and are less likely to fly and evade your spraying.
A side tip on long-term control: Some gardeners simply cover their rose bushes or ornamental shrubs with cheesecloth, tying the cloth’s edges securely at the base of the shrub. This allows sunlight and water to reach the plant, but creates a physical barrier that successfully prevents the rose chafer beetles from attacking the plant.
References:
1. North Carolina State University Extension: Rose Chafer
2. Ohio State University Extension: Rose Chafer
3. University of Minnesota Extension: Rose Chafers
4. University of Wisconsin Extension: Skeletonizing by Rose Chafer
5. Alabama A&M Extension: Insect Pest Management in the Home Vegetable Garden
6. Colorado State University Extension: Insect Control – Soaps and Detergents