Q. I found these gray bugs on my zucchini and they are killing them! They are under the leaves and tons of them. What do I do? Squash Bugs A. Most likely squash bugs. You can plant late, in June, after their infestation time has passed or you can hand pick them as you see them. You must do this as they appear soon after planting and get rid of them as soon as you see them. Do this for about three weeks and the numbers will be greatly reduced. Or you can vacuum them with a handheld vacuum cleaner and vacuum the undersides of the leaves. You can use pesticides suitable for squash bugs but be sure to spray the undersides of the leaves. Do not spray plants when in bloom. Spray very early in the am or at sunset when bees are not active.