Have you seen black and yellow striped beetles crawling around the blossoms of your cucumbers, zucchini, squash, pumpkins and melons? They are cucumber beetles and along with chewing holes in your plants, they spread disease.
The beetles lay small orange eggs at the base of the plants from April to June. The slender white larvae weaken plants by feeding on the roots and crowns. Later in the season, adults chew holes in the leaves and flowers and even in the skin of the fruit. They also transmit mosaic viruses which stunt or kill plants and disfigure fruits, and bacterial wilt, a disease that causes whole branches to wilt and eventually kills the entire plant.
There are several non-toxic ways to deal with the pests. Try one or a combination of methods.
Use a thick straw mulch around the plants to make it difficult for the larvae to climb onto the stems. Reflective mulch, such as heavy-duty tin foil, while not pretty, works well too.
You can cover the plants with a light floating row cover or cheesecloth, but this prevents pollinating insects from reaching the plants. If you go this route, you must hand-pollinate the plants.
Planting radishes, tansy, catnip, marigolds and goldenrod nearby repels cucumber beetles. Next year, throw a few radish seeds right in the hole with the seeds of the crop you are trying to protect and let the radishes grow and go to seed. Also for next year, plant a bit later, even early into June, so the blossoms don’t coincide with the adult cucumber beetle life cycle.
If you are not squeamish, you can pick the insects off the plants and squish them. A slightly less disgusting method is to scoop them up with a folded piece of paper and drop them in a bucket of soapy water. Really revolting, but very effective, is to catch a lot of beetles and mix them in your blender with water. Strain and spray the water onto the plants. A more pleasant spray can be made by mixing geranium stalks and leaves in the blender with water, straining and spraying. Make sure to spray the undersides of the leaves.
Gardens Alive (www.GardensAlive.com or 513-354-1482) sells a powdered clay called kaolin which is mixed with water and sprayed on plants to deter insects. The powdery film sticks to insects’ legs, wings and mouth parts so they quickly leave to find another place to feed or lay eggs. The spray does not affect bees, earthworms or beneficial insects. A 5-lb bag costs $24.95 but will last for years.
As a last resort, use pyrethrins or rotenone to control large infestations.
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