We've written several articles about Douglas Tallamy, the University of Delaware entomologist who maintains that regular gardeners can mitigate some of the ecological damage caused by habitat destruction by planting native plants in their yards.
That's because native plants provide food for native insects that will in turn nourish native birds, helping to sustain the systems upon which life on earth depends. And, critically, these plants support pollinator insects that make possible one out of every three bites of food humans eat.
"Insects run the ecosystem," Tallamy said in a 2019 interview highlighting his appearance at a garden conference in Davenport.
"Insects are not optional," he said. "It is not OK if they disappear. If they go, we go. There is no Planet B."
There's no doubt that insect populations are declining, dramatically so. Ditto for most songbirds.
But his message gives me hope.
I cannot personally stop the destruction of grasslands or the use of synthetic pesticides in agriculture, but I can plant a bur oak or a prairie purple coneflower.
Tallamy's argument about native insects needing native plants is so logical that I didn't realize that there is controversy and disagreement over it, but an article last month by Janet Marinelli of the Yale School of the Environment explained that there is.
Some ecologists have pushed back at Tallamy, saying his conclusions are based only on short-term studies performed at local scales because longer-term, landscape-scale studies have not yet been done. And that is true, the article states. Also, not every study has shown negative effects; Tallamy agrees that critical gaps in our knowledge remain.
Opposing voices also say that the truly destructive forces affecting insects are agricultural intensification, deforestation and land use change, along with pesticide use, climate change and light pollution.
But, again, I cannot do anything about those forces.
I encourage everyone to keep Tallamy's conclusions in mind as they plan their landscapes for the coming year.
According to a paper he co-authored in the 2018 Proceedings of the National Academy of Sciences:
"The widespread preference for non-native plants in the horticultural industry has globally transformed millions of acres from potential habitat into 'food deserts' for native insects, with the unintentional consequence of reducing the abundance and distribution of birds as well."
Pick native plants that will provide food all season — spring, summer and fall, with spring and fall often being sparse. Think cottonwood, native willow and oak trees as well as goldenrod, native sunflower, native aster and evening primrose.
Stop using synthetic pesticides.
If you have night lights, put them on a motion sensor so they're not on constantly. Otherwise, insects that are attracted to light "will fly around and around and exhaust themselves to death," he said.
We need insects.