Where Have All the Insects Gone?

By Nancy Tannler

Have you noticed your windshield is no longer splattered with bugs when you return from a road trip? That might make washing easy, but the bad news is there are less bugs around.

In some areas, entomologists have noted a shocking 76 percent decrease of insects since 1989. The good news is that we could bring back the bugs.

Tom Kaye, a botanist with the Institute for Applied Ecology in Corvallis, spoke with The Southeast Examiner to explain what is being done here in Oregon about the insect apocalypse.

As he tells it, “The problem will only be solved by people understanding a bottom up solution.”

As a biologist, Kaye’s area of expertise is the bottom rung of the food chain. These are the producer organisms – plants, grass, trees, lichens and algae, which convert water, sunlight and carbon dioxide into carbohydrates.

“It is the lack of plant diversity that we are experiencing that correlates directly with the lack of insect diversity.”

Insects feed on an endless variety of foods including plants, fungi, dead animals, decaying organic matter and nearly anything they come in contact with. Some, however, rely on one particular plant or even a specific part of the plant to survive.

“What’s happened is that we’re losing natural insect habitat,” Kaye said, “because of the way we are farming, landscaping and our use of pesticides.”

It used to be that farmers left areas around their crops and shelter belts uncultivated where native species grew. Today’s farming economy requires a farmer to produce on every inch of land so they cultivate from edge to edge.

It was in those uncultivated areas where weeds and wildflowers grew, things decayed, animals could live undisturbed meaning that insects could also thrive.

Kaye said that a study at Iowa State University, STRIPS (Science-based Trails of Rowcrops Integrated with Prairie Strips) over the last 10 years has shown that integrating small amounts of prairie strips on the edges of fields benefits the soil, water and biodiversity.

Native plant species have deep and multilayered root systems and stiff-stems that hold up in a driving rain, which helps stop the runoff of nitrogen, phosphorus and sediment. As one farmer put it, they are affordable and environmentally beneficial as an agricultural conservation practice, plus farmers gain economically by not wasting half their fertilizer due to runoff.

What makes this and other similar local vegetation projects successful is the diversity of native plants introduced into the environment.

“Someone asked me what are the top five plant species best for pollinators.” Kaye said. The answer is that there is no top five; it’s about planting as many native species as you can.

Here in the city the impact of our landscaping is hard on insects too. The traditional yard of a manicured lawn, hardy shrubs and mostly cultivars for decoration doesn’t leave much room for biodiversity; that necessary combination needed for insects to thrive.

The Portland Audubon and Columbia Land Trust have a program, Backyard Habitat, that supports urban gardeners in their efforts to create natural backyard habitats (audubonportland.org/get-involved/backyard-habitat-certification-program).

Every garden can become a bug sanctuary, Kaye said. Some simple suggestions to start with are: let your grass grow longer between cuttings; don’t clean up every pile of clippings, branches and leaves, let it lie for insect habitat; allow portions of your garden to go fallow for periods of time and learn about native plants and grasses and the difference between them and noxious, invasive weeds.

This can prove difficult because some cities and counties have rules in place to enforce a conventional landscape aesthetic of close-cropped lawn and ornamental plantings. These unfortunately, provide no wildlife habitat.

If people felt it was okay to leave areas of their yard untended, it could become the norm. The National Wildlife Federation is calling on cities to pass resolutions and ordinances to increase native plants and help address the extinction crisis. Learn more at nwf.org/community.

When choosing native plants, Kaye recommends planting flowering plants that have a lot of pink and red, like wild currant, roses, cranesbill geraniums, western wallflower, etc. See portlandoregon.gov/citycode/article/322280 to learn what native plants are allowed and what nuisance plants–are prohibited.

The single most important thing we can do is to stop using pesticides. It’s the little things that will bring back these little critters.

Photo of mock orange bush by Kris McDowell

Where Have All the Insects Gone?

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