Some people peg the official beginning of summer at the end of the school year, Memorial Day weekend, or even as late as the solstice. For me, the official commencement of summer is the moment at which I realize I can no longer work in the garden without insects being an issue.
My personal nemeses are the biting flies that seem drawn to the salt in perspiration and leave an itchy welt on the skin. But as any gardener knows, the vegetable plot becomes a bug haven once the weather warms, and insects are as necessary to the overall success of a garden as they are a nuisance to the gardener.
Bees, for example, are an active participant in pollination. Just think of the number of garden vegetables that produce blooms before setting fruit, and the value of bees becomes apparent. Without them, peas, beans, squash, peppers, tomatoes, eggplant and okra would be less bountiful.
We also can be grateful to lady bugs, praying mantises, ground beetles and even flies for eating many of the destructive insects, such as aphids, caterpillars and worms.
In fact, beneficial insects are such a necessary component of the garden ecosystem that it pays to invite them to come live among your crops. If your vegetable garden is located in town and is not near other vegetation, it may be worthwhile to install a flower bed in or alongside your vegetable plot to attract bees and to provide cover for beneficial insects.
Even if you discount the arguments against putting chemicals on food, the usefulness of so many bugs makes it problematic to use insecticide in the garden. No insecticide is perfectly selective, so if you use poison because of a bad bug, you're probably going to kill others.
Eggplant presents a specific dilemma. If I set eggplant transplants in the garden, I am guaranteed to have flea beetles within three or four days. After these tiny black bugs have had their way, the leaves of the eggplant look like someone has pierced them repeatedly with a needle.
Plants with flea beetle infestation don't produce very well, and I have used rotenone, a natural insecticide, on them with mixed results. As with any insecticide, its potency diminishes in the sun and dew, which means that the flea beetles are never gone for good. I also am fairly convinced that my use of rotenone slows pollination.
Squash bugs, blister beetles and bean beetles are the other major villains in Kansas vegetable gardens. Depending on how dense the population becomes, I can usually ignore bean and blister beetles. I may have tattered leaves on bean plants and bites taken out of tomatoes, but only occasionally have I found it necessary to use rotenone on them.
Squash bugs are another matter. I am fairly convinced, after years of being outwitted by them, that nothing short of a pre-emptive strike is going to be effective. Squash bugs lay their eggs on the underside of the squash leaves so their hatchlings - thousands of them - don't have to go far to eat. Then the entire insect community literally sucks the life out of the plant. A perfectly lush squash plant one day can be reduced to a dead heap the next.
As something of an experiment, I have planted far more squash than I ordinarily do. And I've placed it closer together (spaced at 2 feet) in order to concentrate the crop in a smaller area. Once the plants are well-established, I'm going to begin treating the ground beneath them with rotenone in an attempt to forestall the usual squash bug infestation.
By treating the ground early, before the bugs show up, I am hoping to address the egg problem under the leaves; and by not treating the tops of the plants, I may reduce the likelihood that bees will stay away when the blossoms emerge. If it works, I'll be buried in squash.