The culprit that causes cherry leaves to curl may not be a disease. The black cherry aphid (Myzus cerasi) is a tiny insect that feeds on the sap inside plant cells. As the aphids feed, they excrete a sticky substance called honeydew that coats the leaves and fruit, and the honeydew promotes the growth of black sooty mold. In high aphid infestations, feeding damage causes the leaves to curl.
If you notice aphids before the leaves begin to curl, you’ll stand a better chance of removing them. Simply direct a stream of water from your garden hose to knock them off your trees. However, if the leaves are already curling, streams of water won’t dislodge the aphids that are enveloped by the curled foliage.
Using pesticides labeled for use on aphids is one control option, but this method will harm honeybees. Insecticidal soaps will control aphids, but the challenge with this method lies in being able to apply the soap to all leaf surfaces, many of which are out of reach.

The lady bug may be feeding on the aphids.