Dirca leaves
Dirca leaves

From Steve Young: My son Alex took this photo of leatherwood in Saratoga County today while on a trip with Jackie Donnelly.  She has noticed this disease affecting Dirca for some years and it makes the plant stand out in the woods this time of year.  Anyone have any suggestions as to what it is?

Update Sept. 09: Leucanthiza dircella (Lepidoptera: Gracillariidae): A leafminer of leatherwood, Dirca palustris. It seems that this leaf miner and a rust make the leaves of Dirca turn yellow in August.