Monday, June 6, 2011 By: David Velten

Flea Beetles are Back

Flea beetles made quite a nuisance of themselves in the garden last year. I don't remember them ever being that much of a problem in years past. But at least the eggplants were 2 feet tall and able to endure the attack. So I was really dismayed last week to see my new transplants riddled with pin holes and swarming with flea beetles. A check around the garden showed radishes, arugula, lettuce and other plants affected, but none as severely as the eggplants. The picture to the right shows a damaged eggplant leaf with several of the small, black beetles.

Flea beetles are tiny, hard-shelled beetles that riddle plant leaves with pinholes. They get their name from their size and propensity to hop around on the leaf like a flea. They are a serious threat to the gardener and are hard to control due to their many species that feed on different plants, their mobility and their rapid reproduction. Besides the damage they do to the leaves and stems, they act as vectors of disease, and their larvae feed on the roots of the host plant.

Control of flea beetles involves multiple techniques. Physical control involves using a floating row cover fabric such as Reemay to cover the crops before infestation occurs. The problem with this technique is that a slight tear or opening is enough to let the pests in, and they may emerge from the soil where they over-wintered. I have also tried to reduce the population by picking them off the plants and crushing them. But unless everyone in the garden does this, new ones will fly in just as soon as you leave.

Other techniques involve using sticky traps and trap crops. Some control can be had by using white or yellow sticky traps, essentially plastic cards or strips coated with tanglefoot or oil. Trap crops require some planning ahead and involve planting a trap crop near the crop to be protected.  Southern Giant Mustard and radishes have been used as trap crops to protect Cole crops, but I have not seen a recommended trap crop for eggplant.

The last resort is the use of alternative pesticides. Apparently both a dusting of diatomaceous earth and garlic spray have some benefit. Sprays of insecticidal soap and Neem oil are moderately effective.  You have to be careful in applying these so beneficial insects are not harmed and residues don’t get in to the environment

Do you remember the flea beetles from last year? What did you find effective in controlling their damage?

EDIT (6/19): Photo of recent flea beetle damage on a Sun Gold tomato plant. Have you found damage on plants other than eggplant?


Dave Velten said...

Eggplant are flea beetles' favorite food, but they will bother other plants in the garden. I recently found damage on a Sun Gold tomato. Other tomato varieties were not bothered.

Post a Comment