How to Rid Your Garden of Flea Beetles

Source

Fleas in your garden? No, those are flea beetles, a variety of leaf beetle that jumps like fleas. The adults kill by spreading disease while the larvae kill by eating the roots of your plants.

Know your enemy

Flea beetles are tiny and shiny. They are about 1/10 inch long and black or tan metallic with either stripes or spots. They commonly feed on cruciferous plants such as cauliflower, cabbage and broccoli.

The adults overwinter in the soil, emerging when the temperatures reach 50°F. They are most harmful in the spring when they feed on your seedlings, potentially killing them. Later in the season, when your plants are larger, the small holes they make in the leaves won't kill them. It's the diseases (wilt and blight) that they spread as they feed that can kill your plants.

As the adults feed, they mate and lay their eggs on the roots of your crops. When they hatch, the larvae feed on those roots for 2 to 3 weeks, destroying the plants. They then pupate in the soil for an additional 2 to 3 weeks, emerging as adults to start the cycle over again.

Fool me once

Fortunately, flea beetles are not terribly intelligent. You can fool them into thinking that there is nothing to eat by planting out your seedlings 2 to 3 weeks later than normal. The flea beetles will then move on in search of crops to which to feast and lay their eggs.

Alternatively, you can use floating row covers on your seedlings. They are "floating" because you just lay them loosely over your plants. The thin polyester material allows light and rain to get in but keeps insects out.

Scorched earth

A variant of this strategy is to aggressively weed the area around your cruciferous plants. A 3 foot strip of bare soil will discourage the flea beetles who will go off to find something to eat that is easier to access.

Companion planting

Plant herbs such as thyme or mint that have strong scents among your crops to confuse flea beetles who will think that they have accidentally stumbled upon your herb garden. Or you can plant a trap crop such radishes that will lure them away. Root crops such as radishes can withstand the depredations of flea beetles because their roots for which you are growing them are not affected by adult beetles.

The enemy of my enemy is my friend

Plant flowers which bloom in umbrels such as fennel, dill or yarrow to attract beneficial insects such as tachnid flies and braconid wasps. The adults enjoy feeding on the pollen of the flowers while their larvae prefer to feast on flea beetles.

Make your own spray

Combine 5 parts water with 2 parts alcohol plus a tablespoon of dish detergent and spray the foliage of your susceptible crops. You will need to re-apply your spray after each rain event. This will only deter adult flea beetles. The larvae are underground feeding on the roots. Discouraging the adults from eating your crops will result in fewer larvae feeding on roots.

Fall cultivation

A deep cultivation of your garden in the fall will prevent adult flea beetles from overwintering in your soil so that you will have fewer of them to contend with in the spring.

© 2014 Caren White

More by this Author


Comments 2 comments

FlourishAnyway profile image

FlourishAnyway 2 years ago from USA

I'm learning so much about gardening and the pests that live in our gardens by reading your hubs. I guess this little guy is the dum-dum of garden insects because he's so easily fooled.


OldRoses profile image

OldRoses 2 years ago from Franklin Park, NJ Author

Flourish, I'm so happy that you are learning so much! That is incredibly gratifying for me as a garden writer (and speaker). I genuinely enjoy writing about my passion for gardening. Thanks so much for reading and commenting.

    Sign in or sign up and post using a HubPages Network account.

    0 of 8192 characters used
    Post Comment

    No HTML is allowed in comments, but URLs will be hyperlinked. Comments are not for promoting your articles or other sites.


    Click to Rate This Article
    working