| Problem/Symptom | Cause | Solution |
| Leaves curl, rosebuds and foliage wither or become distorted in shape. A clear, sticky substance that attracts ants appears on foliage. | Aphids, semitransparent insects 1/8 inch long that cluster on new growth and flower buds. They suck the juice from the plant and secrete the sticky substance. Aphids can carry and spread diseases. | Aphids may be knocked off plants with a stream of water. In severe infestations, spray with an insecticide or an insecticidal soap. |
| Small, rounded holes appear in leaves. Eventually, the entire leaf surface between the veins disappears. 
| Rose slugs, the larvae of sawfly wasps. The slug is light green with a dark brown head and up to 1/2 inch long. Some species have shiny bodies; others are covered with hair. Rose slugs generally feed on the undersides of leaves; they do not eat buds and flowers. | Spray with a systemic insecticide and make sure the insecticide covers the undersides of leaves. |
| Buds do not open, or flowers are deformed. Petals have brownish yellow streaks and small dark spots or bumps. White and pastel roses are particularly susceptible. | Thrips, tiny orange insects with elongated bodies. Thrips feed at the bases of rosebuds and on the petals of open flowers. They seem to be attracted to light-colored blossoms. | To discourage thrips from attacking, spray plants with a systemic insecticide just before the buds open. If signs of thrip damage appear, remove and destroy infected flowers and buds. Spray infected plants with an insecticide. If the infestation is severe, repeat applications may be necessary. |
| Roses fail to blossom or existing buds suddenly turn black and die. The foliage and the stem surrounding affected buds may also blacken and die. 
| Rose midge, a fly larva that is white and 1/12 inch long. The larvae feed in clusters at the bases of rosebuds. | A soil-applied insecticide applied to the ground around the plants is your best bet. Imidacloprid is the most widely recommended insecticide. Foliar sprays won't help, since the midge spends most of its 2 week long life either in the soil or deep inside rose buds. |
| Leaves become dry and have a bronze sheen. Tiny specks may be visible on the undersides of the leaves. Eventually, thin webbing appears on the foliage.  
| Spider mites, nearly microscopic pests that may be red, black, yellow or green. To confirm their presence, shake a leaf over a piece of white paper; the mites will be visible moving against the white background. Mites proliferate in hot, dry weather. | Knock adults off plants with a strong stream of water. Most infestations can be controlled with regular showers of water. Only if that doesn't work, spray with a miticide three times, three days apart. Use different miticides; mites may build up resistance to a single miticide. Mites produce new generations in a few days, so repeat treatments will be necessary. Avoid insecticide use, as insecticides kill the beneficial insects that keep mites under control. Reducing reflected heat will go a long ways to preventing mite infestations - use cool mulches, underplantings of low-growing annuals and perennials, or use overhead sprinklers and hose down surrounding hard surfaces in hot weather. |
| Small circles or ovals appear in leaf margins. | Leafcutter bees, which are shiny black, blue or purple bees. The bees do not eat the foliage; they use leaf material to build their nests. | Prune out canes that have damaged foliage. Since leafcutter bees are pollinators of several crops, the use of chemicals to destroy the bees is not recommended. |
| Round or oval masses appear on stems and canes. Foliage wilts, turns yellow and drops from the plant. Growth is stunted and flowers are not produced. | Rose scales, 1/8-inch, white, gray or brown insects with crusty shells. Scales usually appear in clusters. | Prune out and destroy heavily infested canes. To prevent scale infestation, spray plants with horticultural oil in early spring. |
Holes appear in unopened rosebuds. Leaves and stems may also have holes or may be chewed off.  | Caterpillars, the larvae of moths and butterflies. Most are yellow or green and up to 1 inch long. Some, such as budworms, attack only the flowers; others eat the leaves and stems. | Spray with Bacillus thuringiensis, called Bt, a bacterium fatal to caterpillars but harmless to plants and other animals. |
Upper surfaces of leaves are covered with small yellow specks. Leaves may curl.  | Leafhoppers, which are triangular, white or light yellow insects 1/8 to 5/8 inch long. They feed on the undersides of leaves and suck the sap from the foliage. Leafhoppers can carry and spread diseases. | Spray with an insecticide or insecticidal soap. In the fall, rake up leaves and remove weeds that can harbor leafhopper eggs through the winter. |
Rosebuds have holes drilled in them, or unopened bud falls over after something drills a hole in the stem right below the bud.  | Rose curculio. Curculio weevils chew on rose buds. Annoying, but whaddya gonna do. Usually they are very small, dark reddish weevils, with a long dark snout. | Hand pick these small weevils. Hold a largemouth jar full of soapy water below the weevils as they will drop to the ground at the slightest disturbance. |
| Growing tips, foliage and canes wilt. Swollen areas up to 1 inch long appear on canes. | Borers, moth larvae that are white or yellow worms up to 1 inch long. Borers enter the canes through wounds and through pruned stem tips. | Cut off the affected area. Make the cut below the swelling on the cane to be sure you remove the borer. To prevent borers from entering canes, apply shellac or white glue to the exposed tips after pruning. |
| Overnight, roses are chewed and trampled. Buds and blooms are damaged the most. Buds and new growth may appear to have been clipped off with pruners. | Deer | See "Deer Control Methods" (Word Doc) for help |
Post time 10-8-2011 08:06 AM
Author
....tak mcm dolu2....meriah.....
