Hard to see clearly but I think I can make out some aphids. The white shreds could be discarded aphid skins (they moult). However, since it is November, the tree will be completely leafless in a few days and it is pointless spraying leaves which are about to fall. Aphids are weak flyers and rain and wind discourage them. So if you covered the tree with some sort of fabric the aphids would have thrived in the sheltered conditions beneath it.

Malathion has actually been withdrawn in the UK for garden use as it is deemed too dangerous. I would never use it in the garden. It is an organophosphate and it will kill the beneficials as well as the pests. I don't know what DT is but if it is having no effect then there isn't much point in using that either. You can knock them back with regular blasts from the hose.

Thanks I am guessing you are right - no doubt the covered being good for them. I will keep an eye on in next year. It was amazing, I see it out my bathroom window and I watch dozens on flies having brunch!

I'm curious about the DT....what is it?

I concur with floral about the aphids. I also suspect that you've been seeing predatory and parasitic insects taking advantage of the situation.

This winter, you should make plans to apply a horticultural oil periodically to the naked tree from top to bottom. The oils, when applied in the dormant season, are extremely effective in smothering the overwintering eggs and nymphs of aphids, scale, and other.

The dormant oil sprays are an essential IPM step in tree fruit culture.

Thanks and for sure I am seeing predators feeding! DT is short for I forget what but kills catepillars and is organic.

Yikes I just looked at leaves. Many leaves have, literally, the entire bottom of the leaf covered with tiny green insects. Unreal. Some leaves have a line on tiny light brown "cavities" lined up along vein of the leaf. Clearly the shells/cocoons.

Its bad!