July 14, 2026

For the last three years I have waged a battle with squash bugs (Anasa tristis). While I found a few individuals on my squash (genus, Cucurbita) this year, they have not been abundant and when I do see one I remove and dispatch it. Even so, every one of my squash plants died early. The cucumbers (Cucumis sativus) are thriving, but they were planted late and after the squash were gone. Squash bugs feed by piercing the leaves and stems to suck out plant sap, causing foliage to develop speckled yellow spots before turning brown and dying. I was still finding my leaves riddled with holes, but what led to the squash demise was the vine above the roots disintegrated. This seemed a different culprit than what I faced in the past. I attributed this to the cool and wet weather we had this spring leading to vine rot. I have similar leaf problems in the sunflower bed to the north and every one of the red amaranths (Amaranthus cruentus) are riddled with bite holes. While watering yesterday I noticed what looked like small beetles on the leaves of several of the sunflowers (Helianthus annuus). When I tried to remove them, they “jumped” to the other side of the leaf. Then one of them flew off. I was looking at a squash vine borer infestation.
When I went online, I found squash bugs and squash vine borers (the “moth” pest) are two distinct cucurbit (cucumbers, squash, melons, and pumpkins) pests. Squash bugs are “true bugs” (flat, dark gray/brown, resembling stink bugs) that suck plant sap while squash vine borers are daytime-flying moths whose caterpillars burrow into stems and kill vines from the inside. The squash vine borer (Melittia cucurbitae) is a daytime (diurnal) species of clear wing (sesiid) moth often mistaken for a bee or wasp because of its movements and the bright orange hind leg scales. Females typically lay their eggs at the base of leaf stalks, and the caterpillars develop and feed inside the stalk, eventually killing the leaf. They soon migrate to the main stem, and with enough feeding damage to the stem, the entire plant may die. The moth is considered a pest as it attacks cultivated varieties of genus Cucurbita (squash, zucchini, pumpkin, and acorn squash). The squash vine borer is native to North America, with some reports as far south as Brazil and Argentina. It lives in most temperate North American states, except the Pacific coast. Southern states have two broods a year (lucky for us).
Pesticides are ineffective to control squash vine borers once the larva gets inside the plant, and since the north bed is meant for pollinators, cannot be used as they would kill what I am trying to feed. I have been trying to catch and dispatch anything I see, but they are fast. An organic control is to inject BT (Bacillus thuringiensis) bacteria into the base of the stem using a syringe to kill the larvae. The injection should be done after the first flowers start to show and again after a few weeks. This method is quite manual and is only useful to small-scale or home gardeners (and too much work for me). You can wrap the lower stem with nylon stockings or aluminum foil to prevent egg laying, which generally occurs within a couple of inches from the point where the stem emerges from the soil. Some gardeners place a yellow bowl filled with water and a drop of liquid dish soap to attract and drown the adult pest. This method provides feedback on the level of infestation and along with daily checking the plants for eggs is popular with organic gardeners. Now I need a yellow bowl.
THOUGHTS: I try and be conscientious about organic farming on my vegetables, but the squash vine borer is testing my limits. Perhaps it is a good thing that most pesticides are ineffective on the insects. I realize I am feeding some insects even as I try to eliminate others. The same is true as I grow weeds (wildflowers) even as I pull others from my beds. Humans tend to make similar decisions with the people they cooperate with. Act for all. Change will come and it starts with you.








