We have a major bug problem —and ironically it is the bugs, not we humans, that are threatened. The first global scientific review of insect populations published last February in the U.K. reveals that insect population declines around the world threaten to cause a “catastrophic collapse of nature’s ecosystems.”

A follow-up report last November in the journal Biological Conservation concluded, “Insects around the world are rapidly declining. Their absence would have devastating consequences for life on the planet.”

The report further points out that 40% of the more than 1 million known species of insect are facing extinction — and that their loss is primarily the result of the heavy use of pesticides and habitat destruction.

In one example cited, 23 bee and wasp species have become extinct in the last century, while the number of pesticide applications worldwide has approximately doubled in the last 25 years. There also are knock-on effects on other animals, such as the spotted flycatcher, that only eats flying insects. Its populations have dropped more than 90% since 1967.

Pesticides called neonicotinoids — neonics for short — are some of the most controversial in use. They are super effective, insect-killing chemicals widely applied to seeds before they go into the ground, and they work by disrupting the central nervous system of insects. Neonics are directly linked to the dramatic decline of honeybees, wild bees and wasps around the world.

The analysis also emphasized that light pollution — specifically artificial light at night (ALAN) — is an important and often overlooked cause of the insect collapse in rural regions. Farmers have long used light deliberately to suppress certain insects, recognizing that ALAN limits their movement, foraging, reproduction and predation.

Experts, including Brett Seymoure, a behavioral ecologist at Washington University in St. Louis, point out that, unlike other drivers of decline, light pollution is relatively easy to prevent by switching off unnecessary lights and using proper shades.

“Once you turn off a light, it’s gone,” says Seymoure, “You don’t have to go and clean it up like you do with most pollutants. I am not saying we can ever eliminate light at night, but we just need to use it more wisely.”

Some conservationists are optimistic that insect populations in urban settings can be rescued by introducing firm targets to cut pesticide use and making parks and gardens more wildlife friendly.

Gary Mantle, chief executive of the U.K.’s Wiltshire Wildlife Trust, contends that, “insects and other invertebrates can recover quickly if we stop killing them and restore the habitats they require to thrive. We all need to take action now in our gardens, parks, farms and places of work.”