Cucumber beetles are a gourd grower’s No. 1 enemy. Once they start reproducing, and they will, your best hope is to keep them under control. If you have grown gourds one year already, then the first step in controlling cucumber beetles is tilling the garden. When it comes to Cucumber Beetles and gourds, cucumber beetles can destroy your vines and your crop. They multiply rapidly and by the end of one season, they can be so thick, some gourds will be devoured by them and you will see cucumber beetles crawling in and out of them like ands in an ant hill.
Cucumber beetles like the gourd leaves and vines, and when danger approaches them, they fall to the ground where they quickly try to scamper into the ground and disappear. cucumber beetles reproduce by burrowing into the ground and laying their eggs in the ground. they also winter over under the ground, and in the spring, new babies pop up in time to much all your new seedlings and will kill a crop before it can start to grow.
In order to get a good start on a new season, you should use a tiller or cultivator to till the garden, every where the gourd vines covered. This will stir up the eggs and being lighter than the dirt, will leave them on the surface where they will die of exposure. If you can till in the fall before winter sets in, and then again in the early spring while it is still cold, this will work even better and you will get a clean start to the season. you will still get cucumber beetles, but not as bad and at least you can get your plants started.
once the vines get growing, be selective about using poisons. Sevin probably works best, but will also do the most harm to your vines and your soil. Neem oil works but you need to do repeat applications as it does not last long. Perhaps an even better way to control cucumber beetles is to bait them and companion planting as well as mulching. A fine netting on the ground covering your garden, if you can afford it, can prevent the cucumber beetles from burrowing and laying their eggs. A fine and tight mulch can also help, but some companion planting may work even better. Cucumber beetles do not like radishes, so plant a lot of radish seeds in the area where your gourds are going to grow.
Avoid using poisons like Sevin, they damage the soil, weaken your plant, and a young gourd vine can be severely stunted and healthy vines can develop a burning that looks almost like mosaic virus. the best way to protect the majority of your crop is by controlling the cucumber beetles numbers without poisoning your plants and good insects.
One thing to do is plant cucumbers away from the gourd vines, use your poison on these to kill the cucumber beetles. Cucumber beetles live cucumbers, hence their name. Second thing to do, get some gourd dust from last years crafts, and mix it with a Sevin powder in with it, and put this in small containers in and around your gourd vines. Try to insure they remain dry. Third, get some tangle foot, it is a sticky trap, get a 1 foot square piece of wood, paint it white and paint a big yellow dot in the center of it, and cover this with tangle foot. Cucumber beetles will fly to it and get stuck.
During the early season, inspect your vines, especially if you see one vine starting to wilt or look ill. Cucumber beetles will eat a hole in the vine and will crawl in and out of it devouring your plants ability to survive.
Once your vines start flowering, the cucumber beetles will start attacking the flowers instead of the vines. If you use Sevin or an equivalent, do not spray flowers after they have opened. This will leave a residual and your pollination insects will be killed as well.
You can also make up a homemade brew with garlic and peppers and radish juices and soap to spray your garden to repel them, but again do not spray your open flowers.
By the middle of the season you will likely have so many cucumber beetles you will think it impossible to have a good crop, but it is amazing how many good and untouched gourds you may find.
If you would like to learn more about growing gourds, please visit The Gourd Reserve with over 700 pages of gourdiculture.