Squash bugs can devastate garden cucurbits in an amazingly short amount of time. While they typically leave the melons and cucumbers alone (unless they’re really hungry), the pumpkins and squash of all varieties collapse and die as massive amounts of squash bugs suck their juices. As they feed, the bugs also release bacteria that further weaken the plant. Squash bugs may even ruin squash fruits by poking them full of holes with their needle-like mouths.
One female squash bug can lay up to 40 eggs at a time. Multiply that by the number of female squash bugs in your garden—or not. Crushing the squash bug causes it to release a disagreeably pungent odor. Picking one up will stain your hands an orange-ish color.
As if all this wasn’t bad enough, some gardeners report that the squash bugs continue to make themselves a nuisance during the winter months by moving into the house.
Where Did They Come From?
The squash bug’s native range extends from the Atlantic to the Rockies and from Canada to South America. For reasons that remain unclear, squash bugs are becoming increasingly prevalent across the entire United States. They can occur anywhere a garden can be found and are now considered a real threat to squash in most states.
Preventing Squash Bugs
Garden sanitation is an essential line of defense against squash bugs. Any dead or diseased plant matter left lying around the garden will attract them, so prune and compost anything that is not green and healthy. Keep the weeds cleaned up, as well. At the end of the season, destroy the old squash plants and let the chickens pick through the soil.
Row covers will physically block squash bugs from plants. However, they must be secured well to prevent access. They will be ineffective if placed on the plants later in the season, as the chances are pretty good that there will be bugs hiding in the soil or mulch.
Growing your squash vines vertically on a trellis helps to some degree, as it provides fewer hiding places for the squash bugs to lurk.
Controlling Squash Bugs
The most effective method of control on an existing squash bug population is to hand-pick and destroy as many bugs and eggs as possible—every single day. Washing the soil around the plants first will drive the bugs up off the ground into the open where they are more easily discovered.
You can increase your chances of success by combining this technique with the use of diatomaceous earth (DE). A generous coating of DE will kill squash bugs. Sprinkle it liberally on all of the plants and also across the surface of the ground to deter new bugs from moving in. A solution of dishwashing liquid will also work, but has the potential to severely damage the plants if not completely rinsed off the foliage after the bugs have died.
Unfortunately, once an invasion begins, it is very difficult to control, so prevention is the best solution. As long as the cause of the recent national squash bug invasion remains unidentified and unaddressed, however, American gardeners will likely be doing battle every summer.
A useful tool for applying diatomaceous earth in the garden.