Yet another pest is on the loose, apparently moving southward from New England. Now it's the redheaded flea beetle (Systena frontalis). It has recently become a serious nursery pest, and if it's a problem for plant nurseries, it can become a problem for you.
The redheaded flea beetle munches on roots and leaves of woody plants, vegetables and perennials including crape myrtle, hydrangea, roses, buddleia, forsythia, blueberries, cranberries, cabbage, beans, beets, sedum, salvia, hibiscus, rudbeckia and coreopsis. After overwintering in the soil, the larvae hatch and start on the roots. Heavy infestations can completely girdle plants.
The larvae are slender and white. Adult redheaded flea beetles are about 1/16 inch long, black with reddish heads and have long antennae. As the name suggests, they jump when spooked.
Gardeners probably won't see them when they're feeding in the root zone, but will notice skeletonized leaves from feeding adults. Redheaded flea beetles seem to be more abundant in rural gardens adjacent to row crops such as soybeans and corn.
So far, there aren't any sure-fire remedies for redheaded flea beetle infestations. They might be caught with sticky traps. They feed on certain weeds, so their numbers might be reduced if gardens are kept weed-free. Researchers are working on chemical combinations they hope will do the trick. Systemic insecticides containing dinotefuran and bifenthrin seem to work well. Dinotefuran is pretty expensive.
Pesticides should be applied in mid- to late spring when larvae are most active. Always follow label instructions when applying chemical pesticides.
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