How to Control Squash Bugs Without Poisons

Tips to Outsmart These Villainous Insects Once and for All

Fern Fischer, Yahoo! Contributor Network
Sep 16, 2010 "Share your voice on Yahoo! websites. Start Here."

To successfully control garden insect pests without resorting to putting poison on your food crops, it helps if you understand the insects' habits and life cycle. One key to effective organic insect control is knowing how and when your actions will have the most effect on the pest.

Squash bugs and squash vine borers are particularly difficult to control. Even poisons are not very effective against adult squash bugs, so save your money, your time and your health, and forget the chemicals. Adult squash bugs are shield-shaped. They have mottled dark brown or gray bodies (wings folded) with orange markings under the wings. They exude a foul odor similar to stinkbugs if they are smashed. You are likely to see squash bug nymphs in your garden in various stages of development, in colors ranging from whitish to various shades of brown or gray. Adult bugs and nymphs suck the juices from squash plants and leaves, and inject a toxin into the plant that causes it to wilt and die. Both squash bugs and vine borers infest summer squash, winter squash and pumpkins. Squash bugs may also be found on cucumbers, cantaloupes and melons...any plant in the cucurbit family.

In their adult stage, squash vine borers are clear-winged moths that fly during the day or at twilight. Due to their appearance and style of flight, it's easy to mistake them for some type of wasp. Adult moths emerge in the summer to lay eggs on your squash plants. When the eggs hatch, the larvae bore into the squash vines and damage the plants. Only squash or pumpkin plants are suitable for borers to complete their life cycle, so you won't see them in cucumber or melon vines. The larvae mature during the summer in the vines, and they pupate in the soil over the winter and following spring. The cycle begins again when they emerge from the soil as adults. Once these pests move into your garden, they can be extremely difficult to get rid of.

Start NOW, in the fall, to get rid of next year's squash pests.

Garden Sanitation
Clean up and destroy all cucurbit debris as soon as the plants die back. Burn the vines and leaves of plants that have been attacked by squash bugs or borers, or dispose of them in trash. Garden debris provides winter shelter for the insects. Do NOT compost cucurbit vines if you had any squash bugs or borers in your garden, or if your plants suffered from any fungal or wilt disease. Squash bugs carry these diseases and harbor them over the winter.

Expose the Villains
Even though it sounds contrary to the humus-building practices of organic gardening, till the area where your infested vines grew - after removing the vines - and leave the area unmulched and bare through the winter. Exposure to the cold weather will help eradicate squash bugs and the pupae of vine borers that are overwintering in the soil.

Crop Rotation
Rotate your cucurbits annually, planting them where non-cucurbit plants grew the previous year. Beans, tomatoes, peppers, peas, potatoes, corn, and other vegetables and flowers will not be bothered by emerging squash bugs or borers in the spring. By not planting the squash in the same area of the garden year after year, emerging bugs will not have a ready food source, and you may be able to disrupt their life cycle more easily.

Physical Barriers
Floating gauze row covers over the plants can be used from the time you plant until the time the first blossoms appear. Once the blossoms appear, you'll need to remove the row covers to give pollinating insects access. Use a layer of organic mulch, such as old hay or shredded newspaper, for moisture retention and weed control between rows and between plants.

Neem Oil
Safe and organic, a neem oil solution sprayed on your squash plants will eliminate chewing squash vine borers and sucking squash bugs in any stage. Neem also interrupts the insects' mating instincts, which decreases the chances of infestation the following year. Begin spraying when the plants have only two or three leaves, and continue to spray once every 7 to 10 days. Neem only affects insects that suck or chew the plants, so it will not affect pollinating insects or beneficial predatory insects. Use neem throughout your garden to control all chewing and sucking insect pests.

Parasitic Controls
Various parasitic wasps and flies are known to use squash bugs as hosts. Hymenoptera Encyrtidae and H. Scelionidae, as well as Trichopoda pennipes are some common parasitic species.

Guinea Fowl (Not for Everyone)
The absolute best way to rid your garden of squash bugs is with your pet guinea birds. A pair of guineas will pick off those bugs and eat them before you even know the bugs are there. Guineas are not like chickens, who would scratch up the entire garden and eat everything in sight. Guineas are delicately selective eaters of insects and seeds.

Guineas also eat a host of other insect pests. They eat ticks ravenously, and they love coddling moths, whose larvae riddle fruit orchards.

And a squawking guinea beats Fido as a watchdog any day.