What is this cottony white fungus(?) growing on all the leaves of my little maple sapling?

Its very fine, almost webby, with occasional tufts here and ther.What is this cottony white fungus(?) growing on all the leaves of my little maple sapling?
Possible infestation of Spider mites!





';Most spider mites have a habit of covering leaves, shoots, and flowers with very fine silken webbing, produced from a pair of glands near the mouth. The silk strands aid in dispersal by allowing the mites to spin down from infested to non-infested leaves, and to be blown by wind currents. When abundant, the silk also may shield the mites from pesticide sprays.





Spider mites are common pests in the urban landscape and can inflict serious damage to trees, shrubs and flowers. Spider mites are not insects but are more closely related to ticks and spiders. Their common name is derived from their ability to produce silk, which most species spin on host plants. Mites are tiny—about the size of the period at the end of this sentence. They can also be very prolific, which is why infestations often go unnoticed until plants exhibit significant damage.





Inspect stippled and distorted leaves to determine if mites are present. Similar symptoms can be caused by pests other than mites, including thrips, leafhoppers and lace bugs. Many spider mites prefer to feed on the lower leaf surface, so examine the undersides of leaves first. A 10 - 20 power hand lens or microscope is essential for clearly seeing the mites. The tiny mites will appear yellow, green, orange, purple, black or nearly transparent. Also visible on the leaf surface may be pale-colored cast “skins” shed by developing mites, and the spherical, often translucent eggs.





An efficient way to sample vegetation for mites is to hold a sheet of white paper or foam board under a branch and tap the foliage sharply. If mites are present, they will be dislodged and appear as slow- moving, dark specks on the paper.





Spider mites are one of the more difficult groups of landscape pests to control. Infestations are easiest to control when detected early, before the mite populations have reached very high levels. Twospotted spider mite infestations can often be traced to the purchase of infested plant material, especially bedding and houseplants. When buying new plants, it pays to inspect the lower leaf surfaces for evidence of mites. Spraying plants with a strong stream of water from a garden hose or faucet can dislodge many mites from leaf surfaces. The approach is generally more effective on smaller plants (e.g., houseplants), with non-dense foliage and low mite populations. Water sprays should be directed upward against the lower leaf surfaces, and the technique will need to be repeated on regular intervals. Low populations of spider mites may be held in check by naturally occurring predatory mites which feed on both eggs and active stages.





Elimination of moderate to heavy infestations of spider mites usually requires the use of specific pesticides known as miticides. Some, but not all, insecticides will also control mites.





Good spray coverage is essential when applying miticides. Thoroughly wet the foliage and try to contact as many mites as possible, paying particular attention to leaf undersides where most mites are living. In most cases, two or more applications at 5-10 day intervals will be needed for satisfactory control. Spider mite eggs that have not yet hatched are unaffected by most miticides; the same may be true of larvae and nymphs that are molting. During molting, spider mites remain inactive beneath the former skin, which serves as a barrier against insecticides. The quiescent mites also do not feed, rendering products that kill by ingestion temporarily ineffective. Consequently, if only one application is made, some of the mites may survive and the infestation will persist.





Effective homeowner options include Kelthane, horticultural oils, and insecticidal/miticidal soaps. Horticultural oils and soaps can be effective alternatives to conventional miticides, but require thorough coverage so that all mite stages are contacted.';





Pics of spider mites %26amp; their webs: http://images.search.yahoo.com/search/im…





Pic of botrytis on strawberry for comparison: http://images.search.yahoo.com/search/im…





Pic of downy mildew on spinach for comparison: http://www.uark.edu/ua/jcorrell/Downy%20…What is this cottony white fungus(?) growing on all the leaves of my little maple sapling?
Are you sure it's not downy mildew caused by aphids? Try washing it off with a water hose.
Sounds like it might be Botrytis.