A MA grower has reported adult flea beetles, which appear to be Redheaded Flea Beetles (cranberry flea beetle) feeding on foliage of mums. Shiny black beetles are about 3/16 -1/4” long with a reddish head (in good light). Antennae are light colored near the head and dark near the tips. Adults feed primarily on young foliage (mostly at night), chewing holes and causing leaf spot damage primarily on the upper surface of the foliage. The damage looks similar to four-lined plant bug injury, but the flea beetle spots are more irregular in shape. Red-headed flea beetles are primarily a pest on woody ornamentals. According to the CT Agricultural Experiment Station other states have reported feeding on Asters, Chrysanthemum, Coreopsis, Rudbeckia, Salvia, Sedum, Veronica and Zinnia. This is a native beetle with a widespread distribution in the US east of the Rockies.
Growers that have had this pest, have reported that it moves into the crop quickly, causes damage and then leaves.
Reference: July 27, 2015 CT IPM Greenhouse Pest Message, Leanne Pundt
Tina Smith, UMass Extension
Photos: Flea Beetle damage on mums, Fea Beetle
Redheaded Flea Beetle The Connecticut Agricultural Experiment Station (2013)
Control of Red-headed Flea Beetles (photos and phenology), University of Delaware