ARE THESE MITE GALLS ON ALEXANDERS?

ARE THESE MITE GALLS ON ALEXANDERS?

Observation - ARE THESE MITE GALLS ON ALEXANDERS?. Description: Hollow raised bits on the leaves of Alexanders, lighter than the rest of the leaf and dotted with bright yellow . . . looks like pollen or butterfly eggs but is neither. The raised areas with yellow are almost all on the tops of the leaves and with the ho

Hollow raised bits on the leaves of Alexanders, lighter than the rest of the leaf and dotted with bright yellow . . . looks like pollen or butterfly eggs but is neither. The raised areas with yellow are almost all on the tops of the leaves and with the hollows on the backs - and nothing to be seen inside any of them. Nearly all are rounded but some are long and a bit more solid (as shown). The plants seem healthy.