There are also black spots on leaves and maybe spider mites. Help. Thank you. 

Thanks for reaching out and for providing photos of your issue. From the third photo you submitteed, it does look like your azalea may hava a spider mite or lace bug infestation. Both pierce the leaves to get to liquid of the plant cells and cause a yellow to bronze stippling of the leaf. You can usually see them on the underside of the leaves (as they appear to be in your photo) but if you have a heavy infestation, you may also see them on the tops as well. The control measures you can take for both are similar. 

If the issue doesn't seem too widespread, a strong spray of water can help dislodge them. You can also use insecticidal soaps or horticultural oils such as neem oil, which are effective against both spider mites and lace bugs. These treatments should be applied thoroughly to the undersides of the leaves, where these pests tend to reside. These options are low toxicity options with respect to their effect on pollinators. It can also be helpful to spray when they are not in bloom, which should not be an issue this time of year. Another good practice is to spray in the evening, near dusk, when many pollinators are less active. 

There is some additional helpful information here in the AskExtension Knowlege Base here: https://ask2.extension.org/kb/faq.php?id=785027 as well as on the UMD webpage on Identifying problems on Azaleas and Rhododendrons: https://extension.umd.edu/resource/azaleas-and-rhododendrons-identify-and-manage-problems. Look for the section 'Lace Bugs'.

Please reach out if you have additional follow up questions. 

-Rebekah

DC Master Gardener