Worms Are Eating the Rose Leaves and Buds

Rose Midge Larvae

• Rose midges look like harmless mosquitoes flying around your rose plants. Female rose midges lay their eggs near flower buds. Once these eggs hatch, larvae feed off of rose buds. Gardeners may see parts of the rose bud that haven't been eaten turn black or fall off of the plant. Treat rose midge larvae with an insecticide that contains diazinon. It is important to treat the soil around your rose plant with the insecticide, because rose midges overwinter in the ground.

Budworms

• Rose budworms, also called tobacco budworms, feed off of the buds and petals of rose plants. Rose buds damaged by these insects fail to open. In addition, gardeners may notice that their rose buds take on a ragged appearance from bite marks. Early detection is key when treating a budworm infestation. Monitor rose plants for small bite marks. Treat your rose plants with a synthetic pyrethoid insecticide. Avoid using an insecticide that contains natural pyrethrin as it is ineffective against rose budworms.

Rose Slugs

• Rose slugs are not actually slugs, but tiny worms that eat rose leaves. These pests are the larvae of sawflies. Gardeners that have a rose slug infestation notice their leaves becoming skeletonized by their feeding. Upon a close examination, you may notice that the skeletonized leaf areas have a thin, brown tissue. To treat rose slugs, spray your rose plant with insecticidal soap. Apply insecticidal soap throughout the growing season, because the spray is only effective for 24 hours.

Caterpillars

• Caterpillars look like worms eating away at rose foliage. Look out for such caterpillars as the tussock moth, orange tortrix, fruit tree leafroller, tent caterpillar and omnivorous looper. Oftentimes, insecticides do not need to be sprayed for a mild caterpillar problem. You can pick off caterpillars and place them somewhere else or dunk them in soapy water. Use a pair of bypass shears to remove damaged leaves. For severe caterpillar infestations, use bacillus thuringiensis, which harms caterpillars by infecting them with a bacteria.