I could be accused of shirking my pest and disease control duties at home. My wife has a espalier peach tree in the glasshouse on which I’d noticed some signs of spider mite a couple of weeks ago but I’d decided not to spray as the peaches are just ripening. Well, the hot and humid conditions have been ideal for spider mite to breed and this is the result.
Once an infestation has got to this level damage limitation is your only course. I’m firstly going to prune out the dead and dying branches and then follow up with a weekly spray of a suitable acaricide.
What I should have done is monitor the tree in late spring when hot weather develops and then introduce the biological control Phytoseiulus persimilis. By the time you see mottling on the leaves the population of spider mite is too large for the biological control to clean up.