Ever stick your nose to inhale the perfume of a rose, and see teeny-tiny bugs jump? Likely you’ve just met some flea beetles. Named for their well-developed hind legs, they jump like fleas when disturbed.
While these insects can be a nuisance to roses, they don’t do any real damage. They’re more commonly found on young edible plants and seedlings, chewing small “shot holes” in the foliage. Flea beetles feeding together can cover leaves with bleached, pitted areas, or ragged holes. They can be serious pests of leafy vegetables, broccoli, kale, cabbage, and collards, along with potatoes, tomatoes, eggplant, and peppers. Since they are so mobile, they can be difficult to control.
Overwintering flea beetle adults emerge in mid- to late spring, become more active when the days get warmer. Adults deposit their eggs in the soil at the base of a host plant where larvae hatch from eggs, feed on below-ground portions of the plant, and then pupate in the soil. Adults emerge to feed on above-ground foliage, then overwinter under protective plant debris, in grassy and woody field borders, and in ditch banks. Depending on location, there may be one or more generations each year, especially in warmer temperatures.
Clean up debris in the fall to remove any overwintering beetles. Protect seedlings with protective coverings until they are in the sixth leaf stage; older plants are less likely to suffer damage. Reflective mulches applied very soon after planting and before plants become infected can be helpful. White sticky traps can be used to monitor or trap adults. Insecticides should not normally be necessary and are not very effective when populations are high.