Over the past couple of days, I have noticed that several flower buds on my zucchini squash plants don’t look healthy. The flower buds have stayed small and turned pale and droopy. Today, I finally took the time to REALLY inspect my plants. What I saw is a lot of bad news.
The holes in the flower buds and the holes in the stems could — possibly — be caused by several kinds of insects. However, the piles of pale green, round globs like tapioca, and the yellow globs too, are most likely frass (poo) from caterpillars.
Around here, a major cause of this kind of damage is squash vine borers. The adult moths lay eggs on the plants. Then, the tiny caterpillars that hatch out of the eggs eat their way inside the plant, where they eat and eat until they have killed the plant from the inside.
I pulled up two of my five zucchini plants to try to find the culprits/caterpillars. As I dissected the plants, this is what I found:
What are pickleworms?
Pickleworms, the caterpillars of a night-flying moth, are a common summertime pest in the South. They are pests I have seen before, but I have not seen such extensive damage to plants from their activity before. Who knew that they would gnaw right into a stem? Not me. At least, not until now.
If the damage had been from squash vine borers, I would have pulled up all five of the zucchini plants and called them an interesting late-summer experiment that I never need to repeat. Since the damage is from pickleworms, I am trying another option. That second option is the use of an organic-approved product for caterpillars.
Organic control for pickleworms
I have mixed up some “Bt for caterpillars” – the product at my house is Thuricide, but others are available – and I’ve sprayed it all over the stems and flower buds of the remaining zucchini plants and my little patch of cucumbers. The name “pickleworm”, if you haven’t already guessed, alludes to a fondness for cucumbers. Since I like cucumbers, too, it would be nice to bring any cucumbers that these plants make into my kitchen, without caterpillars inside.
I planted seeds for cucumbers the same day I planted the zucchini. With a time-to-maturity of 65 days, they seemed less likely than the zucchini to make a crop before the first frost, but they are another late-summer garden experiment. Since they have plenty of flowers on them, the odds look good that I might harvest a couple of cucumbers before the end of October.
This hope for cucumbers depends on me and the Bt. It will need to be re-applied every week, and after every rain, for the Bt to work well.
Wish me luck?