Hi there,

From the pictures, this looks like it could be flea beetle damage. These pests feed on the foliage, and certain species can damage potato tubers. For control, the PNW Insect handbook advises to "direct treatment especially toward where stems of potato vines enter soil. No tuber treatments against flea beetles are available for home gardeners". Some options for chemically controlling this insect are

·        Insecticidal soap

·        Kaolin (applied as a spray foliage it acts to repel pest)

·        Pyrethrins

·        Spinosad

These are not the trade names, just the active ingredients. Make sure to read and follow the label for whatever product you decide to use.