Actually the chief cause of rhododendron death is too much water when the weather is hot. In clay soil with poor drainage, it is very difficult to water without creating a puddling of moisture in the bottom. Raised beds are usually used over clay soil to prevent this. Thrips are characterized by a silvery white discoloration on the leaf's upper surface and silvery on the bottom with small black frass specks. The damage is similar to that from lace bugs. Thrips are a problem in warm and dry climates like California and New Zealand. Most of the standard insecticides and insecticidal soaps can be used. Control for thrips whether an insecticide or insecticidal soap is a contact control and must be applied on the adults. This is most likely done in May in California when they are visible. Locally, biological controls may also be available. It is best to remove infected flowers. Drought or Borers can cause entire portions of a plant die: * Drought can cause entire branches or entire plants to die. We have had several years of drought here and we observe that if rhododendrons and azaleas are not watered during a drought some plants will die, but others will just have one section of the plant die. It seems to be the plants way to conserve what little moisture it has. Prolonged drought weakens plants and often results in the appearance of fungal cankers on the branches of older azaleas. Look for branches that wilt in hot, dry weather in late summer and be sure to water azaleas if drought drags on more than a few weeks. Prune out the affected branches to stop the spread of fungal canker diseases. * If a Rhododendron Stem Borer, Oberea myops, or Rhododendron Borer, Synanthedon rhododendri, is in a branch, the entire portions of a plant beyond (away from the roots) will wilt and die. Borers only affect the portion of the plant away from the roots from the borer. If the borer is in the main trunk, then the entire plant will wilt and die. The plant can be save by cutting off the area with the borer and letting the plant regenerate from the roots. There are no conventional insecticides that will kill stem borer larvae once they are inside the branches. The best control option for homeowners with only a few plants is to prune out and destroy wilting branches in early spring or late summer. On the other hand, entire plants wilt and die slowly when their roots become compromised. There are several causes of this: Root strangulation. This is best prevented by proper root pruning when planting. If the plant is not too far gone, it might be rescued by digging and removing the soil. Then cutting any circling roots that may be strangling other roots. The roots need to be opened up. On larger plants, some of the top must be removed to compensate for the weak state of the roots. Any time the roots are exposed, they must be kept moistened. Roots that dry out will die. Phytophthora crown rot or wilt. This root rot is the major killer of rhododendrons and azaleas. It develops when roots are growing in wet conditions. The rot is more prevalent in warm summer conditions. Plants infected with crown rot caused by the fungi Phytophthora have roots which become clogged with brown fungi internally. The roots get blocked and the plant wilts and dies. There is not much of any cure for crown rot. Some varieties of rhododendrons are vulnerable (Chionoides, Catawbiense Album, Nova Zembla) and some are resistant (Roseum Elegans, Scintillation, PJM). Sphagnum moss and bark dust combined with good drainage seem to prevent crown rot, but do not cure it. Drought. It may have simply dried out. If you plant rhododendrons or azaleas in late spring, it is very important to give them some extra water while they are growing new roots. Never let the soil completely dry out; it's best to keep the soil evenly moist. Too much water or poorly drained soil might be another explanation of sudden rhododendron or azalea death. Rhododendrons and azaleas have very fine, fibrous roots that are easily damaged by waterlogging, even for short periods of time. Voles. Voles, also known as meadow mice, may have chewed on the bark and roots near the crown of the plant. Sometimes they chew all the way around the trunk and kill the inner bark, resulting in death of the whole plant. Keep mulch away from the trunk to discourage voles. Bark Split. The bark may also split when there are wide fluctuations in temperature in the winter. Rhododendrons and azaleas may begin to come out of dormancy if late winter weather is warm; if a cold snap follows, bark injury is likely, especially in sunny, exposed sites. Here is a link that might be useful: Common problems of rhododendron and azaleas.

Nat, I did additional research, and I am 99% certain that these are Western Flower Thrips. While they do not generally cause damage, if brought inside, they can infest indoor flowers. I do a soak of my peonies before bringing them inside to get rid of ants on the blossoms, but apparently those thrips can withstand a greater time underwater! I soaked mine for 45 minutes and brought them inside and it seems as if MOST of them are gone. The water doesn't seem to have any adverse affect on the blooms, since they usually withstand the rain pretty well. Now, to practical matters. What do we do to get rid of these. There are a number of beneficial insects that will help get rid of them, but, I have found, that these seldom work. And not to mention expensive. What sucks is that they are on the blooms, which makes chemical controls a problem as well. If you Google the thrips and beneficials, you should be able to find a good selection. I am beyond that at this point. I see that my iris are also infested, although to a lesser extent. Diatomaceous Earth can be a good way, if used carefully to get them, BUT, again, they need to come in contact with it. I have a systemic organophosphate that I am going to use so that I can get the bugs without having to get the flowers. It has Acephate AND Fenbutaine Oxide, both will kill thrips, and since Acephate is systemic, it will get them without application to the flowers, although the time to get to the flowers probably won't matter THIS year. It will probably help your clematis. I am SURE there will be plenty of people with help on the non-chemical side. I used to be all chemicals - spray the nastiest thing I could find, and now that is a last resort, but these tiny things, in my view warrant it! By the way, LOVE your peony pics. I think we have at least one white variety in common, althoug I forget the name! Sorry for my long-windedness! You are the ONLY reply I have had - and I posted in the Pests/Diseases forum as well! Good luck!!!!

"they seldom do really great harm...." Unless of course, their damage removes so much chlorophyll that the leaves CAN'T do what they are supposed to do. A large population of these insects can also result in the loss of other plant juices in large quantities. I've seen this occur on azaleas, pyracantha, and lantana, just to mention three of the common hosts of lacebugs. Such damage is common and not in the best interest of the plant to ignore. OF COURSE, measures should be taken to restore the plant to a healthier status by controlling the pest. There can be up to 5 generations per year in a warm climate!! But I agree with Jean, the images don't really indicate lacebug damage, though that stippling could make one think so. Here's a question: what does the UNDERside of those affected leaves look like? The bottom of lacebug infested leaves will always be covered with dark fecal matter and the tar-like spots which cover their egg clusters. Very dirty. Is that what you see? Here is a link that might be useful:

MITES: Mites are the most dreaded of the African violet pests because of the damage they cause and the difficulty (and expense) of eradicating them. Mites are tiny arachnids, measuring about 1/100 of an inch. Most people need a jeweler's loupe to see them. The damage is usually in the center, or crown, of the plant. You may notice the crown is deformed, hairy or tight. Mites produce a toxin that causes the leaves to curl, twist and become stunted. Too much light or too much fertilizer can also cause similar symptoms. To kill the mites, you must treat the plants with a miticide such as Avid, Pylon or Kelthane (Dicofol). Cape Cod Violetry and Grower Supply sell these products. Other treatments such as Neem oil may control mites but will not kill them. Some growers choose to throw out plants with mites rather than to treat because of the difficulty and expense involved. MEALY BUGS: These white insects are visible to the naked eye and are about 1/8 to 1/16 of an inch. They may look like specks of cotton on the leaves or leaf axils. Mealy bugs may also be found in the soil, where they will look like grains of rice. The symptoms are generally a plant that fails to bloom, grow and is just suffering overall. Treat with Malathion or Marathon. Marathon is available from Cape Cod Violetry or Grower Supply. Other treatments such as dipping a cotton swab in alcohol will control the problem, but not rid the plant of the insects. THRIPS: These insects are about 1/50 of an inch. You can see them with the naked eye, although a jeweler's loupe may help. Thrips are most often found in the flowers. Gently blowing on the blossom may make them more visible. A classic symptom is yellow pollen spilled on the flowers. The first step in eradicating thrips is to disbud the plant. This means removing all flowers and flower stalks. It deprives the thrips of their favorite food. After disbudding, treat with Neem Oil, Malathion, Marathon, Avid or Conserve. Keep disbudding for at least six weeks. Join us on the African Violets forum.