Flea beetles are small, black or striped beetles that jump away from cabbage family seedlings when touched. These are often seen on cabbage family weeds such as shepherd’s purse and these weeds keep the population of beetles going. The flea beetles eat small round holes in the seed leaves.
Usually, the plants grow out of it and no control is necessary. If damage is severe – more than ten holes in a seed leaf – growth can be checked. A shake of Derris Dust along the rows of seedlings gives good control.