Check your sunflower fields, advises Mike Catangui, South Dakota State University (SDSU) extension entomology.
Large numbers of flea beetles are infesting sunflower fields in Sully County, S.D.
Palestriped flea beetles are about one-eighth of an inch long, black, with two white stripes on the back. They can both jump and fly, which is why they're called "flea" beetles.
Palestriped flea beetles chew on the true leaves, cotyledons, and hypocotyls causing the sunflower seedlings to wilt and die, Catangui says. Injured leaves become riddled with holes giving them a lacey appearance.
Spraying with an insecticide may be justified if 20% of the stand (one out of five seedlings) shows extensive feeding by the flea beetles, Catangui says.
Baythroid (2.8 fluid ounces per acre) is specifically labeled for the pest. In addition, Sevin XLR Plus (32 fluid ounces per acre), Warrior (2.56 fluid ounces per acre), and Mustang MAX (2.72 fluid ounces per acre) were effective in reducing palestriped flea beetles in an SDSU Extension Entomology research near Onida in 2001-2003.