Today 
Tomorrow
Nesting female bees cut out immediately obvious elliptical shapes from the edges of a leaf to make their cells for laying eggs. Since one female might need 20 or so cells, that's a lot of leaf cutting, particularly when the bee keeps returning to the same plant. It's only a significant problem when young plants are being defoliated or you're growing specimens for a show.
Solution
Organic
Wait for the solitary female and swish her away. Try to avoid killing the bees because they're invaluable friends to gardeners, pollinating flowers.
