This photo, sent in by a reader from Bloomington, MN, shows the mottled and spotted leaf on an orange tree. Q: I have an Orange Tree which I move indoors for the winter. The leaves are mottled and spotted with tiny black spots on the bottom. I do not see insects or webs. A: Hello. I'm glad you've turned to AskExtension! The spots appear to be the work of a sucking type of mite called a spider mite. This is also evidenced by the presence of webbing around the leaves. If you were to hold a blank, white sheet of paper under the affected leaves and shake the leaves, you would see tiny reddish dots (smaller than a period mark) land on the paper. If they start moving on the paper, they're definitely spider mites. Spider mites like a dry environment which is what our Minnesota homes are like in the winter. Here is more information about their control should you choose to try to keep and treat your tree. Learn how to control these tiny critters: Managing insects