How can I control the yellow insect with a black stripe that is invading my squash and cucumber plants?


Is there something I can do to eliminate the squash bugs, yellow bodies with black stripe, from invading my squash and cucumbers? Should I dispose of the dead leaves of the plants in the compost? Is there a way to treat the soil now so in the spring they will not destroy the plants? What can I do in the spring when the new plants germinate? I have tried companion planting with radishes, mulch around the base of plants and soap spray which is really tough as the leaves get bigger and the few that I manage to hit with spray seem to have millions of cousins who return in 5 minutes. I would not like to use Sevin.


Jonathan Foster, Community Education Assistant

From your description, I think you are dealing with cucumber beetles, as opposed to true squash bugs. The bad news is that both can indeed be an irritating pest on your cucumbers and squash; the good news is that the controls are similar and unless the infestation is truly bad, keeping them managed during certain portions of your crop’s life cycle will significantly mitigate damage. While clusters of the insects can be unsightly, mature plants usually weather them with only cosmetic damage. And you don’t need to apply chemical controls to get good results at the scale of a home garden.

Young plants are the most likely to be severely damaged by the insects (and cucumber beetles can carry the pathogen responsible for bacterial wilt), and those baby plants are generally going into the garden during late spring/early summer, when cucumber beetles are seeking out food and places to reproduce. A double strategy of tightly covering your garden beds with floating row cover (no gaps!) until those crucial weeks are over, and daily scouting of your juvenile plants for eggs, nymphs, and adult critters will be the most effective approach to preventing the beetles from getting a foothold among your plants.

Once you get into high summer, you can remove the row cover to give the mature plants more air and light, but continue to scout for beetles–at that point, you should really only have to deal with the occasional straggler, as your plants have been protected during their vulnerable period in the beetle’s life cycle. We do recommend keeping a nice thick layer of mulch beneath your plants, removing any infested plant material (either hosting large populations of beetles or showing signs of bacterial wilt), and keeping any dead garden debris tidied up. If you have a serious infestation or if bacterial wilt shows up, you should dispose of the plant material rather than composting it, though pursuing the row cover approach and keeping your compost pile at a distance (as well as properly managing it) really should mitigate any minor problems with overwintering in the pile after one season.