Insects That Eat Roses

The insect, Euthochtha galeator, causes rose leaves to wilt and wither.

Roses are beautiful landscape plants that can be challenging to grow because of the many insects that feed upon them. Usually insects are not fatal to roses, but they they can stunt or kill plant parts, which can affect a rose's cosmetic appearance and flowering. Often these insects are managed without using chemical methods. By knowing how to control insect problems you'll increase your odds of producing beautiful roses.

Aphids

Aphids attack roses more than any other insect. Using their mouth parts they suck on plant sap. Although a small population of aphids doesn't do much damage, they reproduce quickly, reaching large numbers that cause problems such as distorted growth. They can also reduce the quality and amount of blooms. Ants protect aphids for the sticky honeydew they secrete. Other insects, including syrphid flies and lady beetles, are natural enemies of aphids. Rose aphids (Macrosiphum rosae), the most common aphids, are pink or green with soft, pear-shaped bodies.

Rose Midges

The rose midge (Dasineura rhodophaga), is a fly that lays eggs in the shoots and buds of roses. The insect's small, legless larvae are white maggots measuring roughly 1/16 inch long, according to the University of Minnesota. Stem tips wither and buds become bent or blasted as a result of larvae feeding on roses. Their feeding also causes growing shoots and buds to turn brown and then eventually turn black. Control them by pruning out infested buds or using systemic insecticides.

Thrips

Flower thrips (Frankliniella tritici) and western flower thrips (Frankiniella occidentalis) are the most common types of thrips that eat roses. Adult females of both of these species have feathery or fringed wings that are yellowish brown. They're extremely tiny at less than 1/16 inch long, says Clemson University. Remove any infested blossoms. Although insecticides can be used, the timing of these sprays is crucial, as they should be applied before any thrips enter unopened buds.

Japanese Beetles

Japanese beetles (Popillia japonica) are easily identified by the adult beetles' green metallic bodies and legs. White hairs on the ends of their abdomens set them apart from similar-looking beetles. These beetles feed on leaves, flowers and buds of roses using their chewing mouth-parts, as they eat everything but the leaf veins. The best control method is handpicking the insects off of leaves and then dropping the beetles in soapy water.

Rose Curculios

Adult rose curculios (Merhynchites bicolor) are red and have long black snouts. Their legs and undersides are also black. These weevils particularly eat shrub roses, although they feed on all rose species. Adults feeding on shoot tips and buds cause dead shoot tips and damaged petals. Rose curculios feeding below buds can cause stems to bend over. Larvae are legless and have a color similar to rose midge larvae. Control small numbers by hand picking off adults.

References

• University of Minnesota; Insect Pests of Roses Kevin Stroom, Jody Fetzer, et al; 2008
• University of Minnesota: Bud Shoot Feeders
• Clemson University; Rose Insect & Related Pests; Janet McLeod Scott and Joey Williamson; November, 2009
• University of California; Roses; September, 2008
• University of Florida; Coreid Bug; Frank W. Mead