Scott Eckert: Controlling squash bugs
It doesn’t seem to matter how hard you try, squash bugs always seem to find your pumpkins and squash in your garden.
They are controllable, but it really is a matter of staying ahead of them to try to reduce the population, just long enough to actually be able to harvest squash. It will soon be a tasty vegetable you can cook on your grill this summer.
Squash bugs are the gray, shield-shaped bugs that feed on squash and pumpkin plants. If you have had problems with these insects in the past, you know that they are almost impossible to control when mature. This is because the squash bugs have a hard body that an insecticide has difficulty penetrating. Thus, spraying when the insects are small is important.
We are now seeing the eggs and nymphs of the first generation. Look on the underside of the leaves for cluster of brick-red eggs and small green insects with black legs. These nymphs will eventually become adults, which will lay eggs that will become the second generation. The second generation is often huge and devastating. Therefore, it is important to control as many squash bugs now as possible.
Because squash bugs feed by sucking juice from the plant, only insecticides that directly contact the insect will work. General use insecticides such as permethrin (Bug-B-Gon Multi-Purpose Garden Dust; Green Thumb Multipurpose Garden and Pet Dust; Bug-No-More Yard and Garden Insect Spray; Eight Vegetable, Fruit and Flower Concentrate; Garden, Pet and Livestock Insect Control; Lawn & Garden Insect Killer), malathion, and methoxychlor provide control if a direct application is made to young, soft-bodied squash bugs. This means that you must spray or dust the underside of the leaves, because this is where the insects live.
— Scott Eckert is a Kansas State Research and Extension agent for Harvey County. Horticulture is his specialty.