My in-laws Asian pear trees got lots black spots on the leaves. Fungal infection?
Looks like Scab to me:
The way the spots are raised means it could be pear leaf blister mite. When they are active the leaves are red/pink and they turn brown like this after the mites die. But its hard to be sure, I would not be surprised if it was scab or some other disease like fabrea leaf spot.
Any of these pics look like yours? https://www.google.com/search?q=pear+blister+mites&es_sm=122&tbm=isch&imgil=zDP1tJA6aK3AEM%3A%3BFJ96SUsjfbtZTM%3Bhttp%253A%252F%252Foregonstate.edu%252Fdept%252Fnurspest%252Fpear_leaf_blister_mite%25252520closeup1.htm&source=iu&pf=m&fir=zDP1tJA6aK3AEM%3A%2CFJ96SUsjfbtZTM%2C_&biw=1600&bih=775&usg=__fqHpsGtHVhtijDFiHXCgLP1q7RI%3D&ved=0CDAQyjc&ei=mKWBVfWeFriCsQSAtYegDw#imgrc=zDP1tJA6aK3AEM%3A%3BFJ96SUsjfbtZTM%3Bhttp%3A%2F%2Foregonstate.edu%2Fdept%2Fnurspest%2FImages%2Fmites%2Fpear%2520leaf%2520blister%2520mite%2520damage%2520crn.jpg%3Bhttp%3A%2F%2Foregonstate.edu%2Fdept%2Fnurspest%2Fpear_leaf_blister_mite%2520closeup1.htm%3B684%3B482&usg=__fqHpsGtHVhtijDFiHXCgLP1q7RI%3D
Looks exactly like photos I’ve seen of Fabrea leaf spot, but I see what Scott is saying about the raised “bumps”. Is that why blister mites are named such?..because they cause blisters on the leaves?
Don’t think it’s blister mite. My Seckel branch had them; there are no brown spots and the leaves are far more misshapen.
I have had many years of blister mite and it can look very different based on severity, weather, and leaf maturity. I have seen it looking very similar to those pictures, and the raised bumps are not common in diseases.
Interesting, thanks Scott!
Scott, I thought it might be blister mite, too, due to the bubbling effect. Guess the best thing for Tony to do is send his pics into the local Ag agent and see what they have to say. Or, treat for both, and he’s covered.