My recent column about the lily leaf beetle generated several e-mail messages. I learned that the scarlet scourge has invaded Steuben and East Millinocket and that several gardeners learned how to deal with this alien pest without resorting to toxic chemicals.

I was disturbed, however, by one readers’ decision to bypass mechanical control (hand-picking) and treating his lilies with neem, an ecologically safe biopesticide derived from seed of the neem tree, choosing instead to spray them with a product that contains beta-cyfluthrin and imidacloprid. Beta-cyfluthrin, a pyrethroid pesticide, is labeled as “highly toxic to fish and aquatic invertebrates” and “a high risk to honeybees and other arthropod species.” Translate the latter to “highly toxic to all insects.”

Chemically related to the tobacco toxin nicotine, imidacloprid is classified as highly toxic to bees and has been implicated as the likely cause of colony collapse disorder, a serious problem affecting honeybee hives across the world. Other insects, including predatory insects such as ladybird beetles and lacewings, are targeted by imidacloprid. It is also toxic to earthworms.

Then I read the front-page story about invasion of Bangor lawns by another non-native insect species, the European chafer. Imidacloprid was recommended by Maine state authorities to control this pest as well.

I imagine local discount stores and garden centers stocking up on products that contain imidacloprid to meet the demand. It feels to me like an ecological disaster in the making.

Insects have been described by noted Harvard biologist E.O. Wilson as “the little things that run the world.” They pollinate plants, recycle nutrients tied up in dead plants and animals, keep populations of insect herbivores under control, and aerate and enrich the soil. They are of paramount importance in the transfer of solar energy through the food web, providing food, either directly or indirectly, for most other animals.

Of the 9 million or so insect species on Earth, only 1 percent interact negatively with humans. The remaining 99 percent are a vital part of the foundation supporting all life on Earth. While insects have managed and could continue to manage quite will without humans, we would disappear in a short time if insects ceased to exist. Yet we seem to be trying our hardest to accomplish just that.

Before rushing out to apply imidacloprid or any other toxic pesticide to lilies, turf grass, or any other plant, I implore you to read Douglas W. Tallamy’s new book, “Bringing Nature Home, How Native Plants Sustain Wildlife” (Timber Press Inc.). Tallamy, professor and chair of the department of entomology and wildlife ecology at University of Delaware, writes pithily about the many ways insects interact with native plants to maintain biological diversity. He builds a strong case for the role of gardeners in sustaining the diversity of insects that are the primary food source for birds and other animals.

Our gardens and landscapes can offset the loss of biodiversity caused by urban sprawl, habitat fragmentation, and invasive species. The first step is to plant mostly native plants, species that share an evolutionary history with native insect species and thus can be expected to function as their food source.

Another crucial step is to avoid the use of toxic pesticides that kill nontarget species. Better to lose the alien lilies to the alien beetles, better to shrink the size of our lawns or replace them entirely with native plants, than to continue the current drain in biodiversity.

It all came into focus for me recently as Marjorie and I were walking through the garden. Looking through the foliage of a young red oak to view new seed cones on a distant balsam fir, Marjorie pointed out that the upper leaves of the oak were ragged and torn by the nibbling of some insect. Later that morning we spotted a warbler in the oak, feeding on whatever was feeding on the leaves. And so it goes, or should.

Send queries to Gardening Questions, P.O. Box 418, Ellsworth 04605, or to rmanley@ptc-me.net. Include name, address and telephone number.