This is what I get for procrastinating and not putting on my row cover in a timely manner–the cucumber beetles have invaded, both spotted and striped. As their name implies, cucumber beetles like to eat cucumbers, but they also enjoy feeding on squash, melons and pumpkins (any cucurbit will suffice). In no time at all they’ll munch through lovely green leaves then leave some eggs, which will hatch into larvae. The larvae will then start eating your plant’s stems and roots below ground. If that wasn’t enough damage, the adult cucumber beetles also fly from plant to plant spreading disease like Mosaic and Bacterial Wilt.
I imagine that I’m not the only gardener with a cucumber beetle infestation. If you see either of the above culprits in your garden, here’s what you can do.
- Spray. If you are using only organic products in your garden, you can spray with Spinosad or Pyrethrum. Spinosad is a bacterial found in crushed sugarcane that is harmful to many insects. Pyrethrum in an organic insecticide made from chrysanthemums. If you are not opposed to using chemical insecticides, spray with one safe for vegetable plants like permethrin. NOTE: No matter what spray you use (organic or chemical), spray in the late evening or very early morning so you have little chance of harming honeybees when you spray.
- Hire a known killer. Green lacewings, ladybugs, and spined soldier bugs all like to feed on the eggs of the cucumber beetle. Buying beneficial insects will not provide immediate control of an infestation but the addition of beneficial insects to your ecosystem will provide long term help to manage natural infestations. NOTE: If you choose to spray, even organic pesticides will harm beneficial insects.
- Deter the bad guys. Sprinkle kaolin clay on your plants to provide a filmy layer that creates an unattractive environment for egg laying as far as cucumber beetles are concerned.
- Prevent the problem. Protect your plants by covering them with a lightweight floating row cover as soon as the plants are in the ground. Once your plants are blooming, you will need to remove the row cover so insects can get to the blooms and aid in pollination.
What did I do about my problem? Since I am using only organic products in our garden, I sprayed last night with spinosad. If I had noticed only a few cucumber beetles, I might have taken a ‘watch and wait’ approach and given my ladybugs a chance to work, but I had beetles on about 75% of my cucumber plants and about 50% of my squash so I chose to spray. If I don’t see results in the next couple of days I may spray with neem-pyrethrin spary. I have also planted the next two rows of cucumber and squash plants and I will definitely get my row cover on them before the seeds even sprout!