Irene Shonle, CSU Extension, Gilpin County. Many people feel that climate change is our most pressing environmental issue right now, but there’s one that is equally scary that few people have even heard of, although it is starting to make the news.

It’s the dramatic decline in insects worldwide, which some are calling the insect apocalypse. Both the biodiversity and the biomass of insects is threatened worldwide. A recent paper in Biological Conservation (Sánchez-Bayo et al. 2019) presented a comprehensive review of 73 historical reports of insect declines from across the globe. More than 40 percent of insect species are declining and a third are endangered, the analysis found. The rate of extinction is eight times faster than that of mammals, birds and reptiles. The total mass of insects is falling by an alarming 2.5 percent a year, meaning they could vanish within a century. Professor Dave Goulson at the University of Sussex in the UK says, “It should be of huge concern to all of us, for insects are at the heart of every food web, they pollinate the large majority of plant species, keep the soil healthy, recycle nutrients, control pests, and much more. Love them or loathe them, we humans cannot survive without insects.” Loss of insects could cause a cascading decline of animals all the way up the food chain (and vertebrates have also experienced a 50 percent decline in the last 40 years).

If you are of a certain age like I am, you can probably see the decline in your lifetime – when I was a kid, the windshields of the car used to get smeared with bugs in the summer, and it was always quite a chore to clean it all off. Now, that is hardly an issue. Others somewhat fondly remember eating bugs when bicycling as a youth, but no longer, perhaps a strange thing to miss, but there it is.

The decline is widespread across insects, not just for specialists that occupy particular ecological niches, but also for many common and generalist species. The main drivers of species decline, according to the study are, in order of importance: Habitat loss and conversion to intensive agriculture and urbanization; pollution, mainly that by synthetic pesticides and fertilizers; biological factors, including pathogens and introduced species and climate change.

The bad news is that many pest insects such as flies, mosquitoes, cockroaches and agricultural pests will probably thrive with the warmer conditions of climate change, because many of their natural enemies, which breed more slowly, will disappear, according to Dr. Goulson “It’s quite plausible that we might end up with plagues of small numbers of pest insects, but we will lose all the wonderful ones that we want, like bees and hoverflies and butterflies and dung beetles that do a great job of disposing of animal waste.” Increases in mosquito populations could lead to widespread spraying of insecticides, or even the release of GMO mosquitoes designed to wipe out an entire species, in an effort to control diseases such as malaria, which would accelerate the downward spiral.

While certainly, addressing climate change is important, there are other solutions that could help immediately. One would be to restore hedgerows to agricultural enterprises. A study in the Journal of Economic Entomology, (Morandin et al. 2016), documented that hedgerows are economically viable to growers by enhancing beneficial insects and natural pest control and pollination on farms. Between pest control and pollination services by native bees, the return time on the cost is just 7 years.

Another even more local solution can be found in all of our yards. Every yard and every native plant can help restore habitat. Native plants support many times more insect biomass than exotic plants imported from Asia or Europe because native plants have a shared evolutionary history with insects and other wildlife. A yard of 70 percent native plants can support both insects and birds, and it is within all of our reach. We can still turn the tide.

The CSU Gilpin County Extension Office is located at the Exhibit Barn, 230 Norton Drive, Black Hawk, CO 80422, 303-582-9106, www.gilpin.extension.colostate.edu. Colorado State University Extension provides unbiased, research-based information about, horticulture, natural resources, and 4-H youth development. Colorado State University Extension is dedicated to serving all people on an equal and nondiscriminatory basis.

(Originally published in the March 14, 2019, print edition of The Mountain-Ear.)