Red turnip beetle
Department of Entomology, University of Minnesota
Size: 1/2 inch long
Where/When: Feeds on leaves, stems, and flowers of plants in the mustard family (Brassicaceae), such as cabbages, turnips, radish, hoary alyssum, sweet alyssum, and wild mustard. Most prevalent in areas with sandy soils. Adults are active early June to early July. May also be seen from late July through early August.
Significance: Heavy defoliation may stunt or kill the plant, particularly young seedlings. High numbers are rare.