Squash Bugs, Hornworms, and Deja Vu

This is all seeming so familiar, and we don’t like it.


Last year we battled three main insect pests in the early growing season: squash bugs, squash vine borers, and tomato hornworms. We’re seeing two of the three back again this year for another round, and we’re likely to see the third soon. Squash bugs lay tiny brown eggs on the underside of cucurbits (for us, mainly squash and zucchini). When the adults hatch, they set about eating the leaves of the plant with a vengeance.

We called ourselves having found a solution for the squash bugs and squash vine borers this year, because we placed all the squash and zucchini on one row so we could place Agribon insect barrier row cover on them. We knew we would need to pull the row cover when they began to bloom, but we figured by then they would be stronger and more able to withstand the onslaught of the squash bugs.

We placed the row cover Friday but we were obviously too late. When Amanda did a routine check of the squash Saturday, she found one plant, then another, then many more squash plants already infested with squash bug eggs on the underside of their leaves. She laboriously removed the eggs from the leaves, but she also found some adult squash bugs already active, so we know we are already infested. We pulled the row cover. Not much point in it now.

We haven’t yet seen signs of the squash vine borer (the telltale wound on the side of the stem where the borer pierces the plant and proceeds to kill it from the inside out), but we assume we will see them shortly. When we see the wound on a plant, Amanda has learned to open up the stem, kill the borer, and then bury that portion of the stem so the plant can develop new roots. It sounds laborious, and it is, but nearly half the squash and zucchini we ate last summer was from plants Amanda had rescued in this way, so we’ll keep doing it.

tomato-hornwormThe tomato hornworm is my favorite pest to hate. Blessed with coloring that mimics the stem and leaves of a tomato plant perfectly, the hornworm starts out small enough that it’s virtually impossible to find on a tomato plant. As it munches quietly on the leaves and tender shoots of the plant it swells up dramatically and becomes gradually easier to spot. It’s usually just before the hornworm has killed the plant that I’m able to spot it. Amanda is more experienced and can usually spot the hornworm a day or two sooner. When we find one, it’s quite satisfying to squish it with a rock and watch hornworm guts spill out onto the ground, but it’s always bittersweet, because those guts are the digested flesh of our tender tomato plants.

One cautiously optimistic note here; it’s far too soon to tell, but we may have found something that helps a little. This year we interplanted marigolds and basil with our tomatoes, and (he said quietly and carefully) we have not yet seen a hornworm on the tomatoes. The only hornworm we have seen this year was on the peppers, which are not interplanted. Last year the hornworms focused exclusively on the tomatoes, so we have some hope that the interplanting is helping. We shall keep you posted.

More cause for optimism: we have already spotted some ladybugs on Veg Hill, so we are hopeful they will help us keep the aphids in check this year. We’re also seeing a good assortment of lizards and frogs, always welcome in an Alabama food garden because of their love of insects (both pests and beneficials).

1 thought on “Squash Bugs, Hornworms, and Deja Vu”

  1. I planted marigold seeds around all of my 22 tomatoes; though not all of those have germinated. The tomatoes with marigolds have no pests whatever. I haven’t seen any kind of bug pest on these tomatoes at all. The biggest problem I have is that the four that is used tomato cages on all flopped over in the wind. Even on the non marigold tomatoes the only pests that I have seen are Colorado potato beetles, which ate one tomato to the stems. I have a mixture of both French and African marigolds; I bought the seeds before I know the difference. Luise Riotte author of “Carrots Love Tomatoes” advises that the French marigold is the most effect pest repellent I also have to report that the marigold tomatoes are the biggest and most vigorous, although this could also be because the soil there is better.

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