Hi- this injury is consistent with striped and spotted cucumber beetle feeding. Adults emerge in spring and start feeding on many plant species but are especially fond of the squash family. Please see our web page for detailed information on preventing and controlling this significant pest.
https://extension.umd.edu/hgic/topics/cucumber-beetles-spotted-or-striped-vegetables
Jon

Thanks for your prompt reply!   The web page was very helpful.  We have definitely identified striped cucumber beetles on the prowl.  We are wondering... the text instructs us to "lightly till" the soil in the fall or spring to kill eggs and larvae.  Could you please define "lightly"?  How deep should we go?  Thanks again!

Hi- four to six inches would be sufficient. They can overwinter in weeds and rough areas around the garden as well. If you till your garden, be sure to cover the bare soil with tree leaves or a cover crop.
https://extension.umd.edu/hgic/topics/cover-crops-protect-and-improve-your-soil
Jon

That's helpful info, thanks.  Clarification:  The Prevention/Control section of the cucumber beetle web page says that we should remove garden debris in the fall.  So your reply indicates that tree leaves don't fall in the category of "garden debris."  Is that true of pine needles, too?  Thanks

Right- garden debris in this context refers to any vegetable plants and weeds in the garden. Tree leaves are a good kind of debris (usually called yard waste) that will not spread diseases in the vegetable garden. They protect soil, provide nutrients after breaking down, and can be re-used as mulch during the growing season. Just pull them back off the garden beds to prepare soil and plant and move the leaves back to surround seedlings and transplants.
Jon