Aug. 15, 2024

Many of us have had a moment when the mosquitos were biting or the squash bugs were ravaging the garden and we wished that there were no insects. What if that wish came true? We have seen headlines about an “insect apocalypse.” Are we actually losing our insects?

I talked with a couple of experts and looked at some of the scientific articles on the subject. Here is what I learned: Insects are a large and crucially important part of the life on Earth, and we cannot afford to lose them. And yes, there are insect declines, and there are things we can do to help.

BUGS ARE A BIG DEAL

Scientists are expressing strong concerns about insect decline.

“Over the past decades, evidence has mounted that the Earth’s entomofauna [insect life] is in an ongoing state of collapse,”  said a Norwegian scholar in ScienceDirect.com.

An elm calligrapher beetle sports distinctive spots. Photo by Meghan Cassidy.

A headline from 2021 in The Guardian said, “The Insect Apocalypse: ‘The World Will Grind to a Halt Without Them.’” 

The scientific community seems to agree that the world would “grind to a halt without them.” 

A chapter in the 1996 book, In Search of Nature, by the famous biologist E.O. Wilson, is titled, The Little Things that Run the World. 

He was speaking of invertebrates, not only insects but spiders, mites, worms, tardigrades and the rest of the animals without backbones. They run the world in part because there are huge numbers of them. Most living things are invertebrates, and insects make up three-quarters of the animal and plant species on Earth. 

The jobs insects do are crucial to life on our planet. We eat fruits, vegetables and grains, and insects make most of that possible. They provide food, directly or indirectly, for much of our wildlife and they could help feed us, too. They break down dead things and help return them to soil. And they feed our cultures and our sense of wonder.

A bumblebee. Photo by Meghan Cassidy.

Butterflies — and also bees, wasps, flies, moths and even some bats and birds — visit flowers for food and in the process they pick up and also brush off some pollen. For flowering plants, the pollen is essential for the production of seed and the growth of new plants. Crops depend on pollinators and therefore we depend on them. Without animal pollinators, we would not survive, according to the U.S. Forest Service.

Dr. Jaime Baxter-Slye, clinical assistant professor of ecological education at the University of North Texas, added to the list of things insects do for us. 

“A lot of them are detritivores, they eat the dead decaying matter,” she said. 

So, if those insects disappeared, much of that stuff would just pile up. 

Another critical function of insects is being dinner for countless birds, reptiles and amphibians, mammals and other insects. If insects suffered big declines, it would mean starvation for many wildlife species. 

There are parts of the world in which insects are a noteworthy part of human diets. In fact, more of us might want to consider including insects in our diets. An article in Ecology and Evolution, reported that insects are a source of protein and nutrients comparable to meat and fish. And cows cannot convert plants to food for us as efficiently as insects do. Maybe eating bugs would take some getting used to, but it might be worth it.

An Arizona mantis. Photo by Meghan Cassidy.

It would be good if we looked at insects in a more positive way, according to Sam Kieschnick, Urban Wildlife Biologist with Texas Parks and Wildlife Department. 

“You notice that the other meaning of ‘bug’ is to be a pest. Words like ‘bug’ or ‘weed’ are loaded terms that convey ickiness,” he pointed out, even when we are talking about fascinating insects or valuable native plants.

Our lives are richer because of butterflies fluttering across a prairie, the drowsy humming of bees in a garden and the soft blinking lights of fireflies tracing swirling paths through a summer night. Nights with fireflies, and the chance of catching magic in a bottle, have become uncommon as these beetles lose habitat or are poisoned by pesticides.

ARE INSECTS DISAPPEARING?

Have you noticed that on road trips, the windshield stays clean longer? We don’t run into as many insects while driving as we used to. That’s even been the subject of some scientific studies.

From 1996 to 2017, a Danish biologist found that insect splatter fell by 80 percent on one of the routes he regularly traveled. On a longer stretch, they plunged 97 percent.

But we need to consider all the different kinds of insects, not just the ones that fly across the highway. 

As Baxter-Slye put it, “We don’t know unless we go look. We have to rely on researchers doing data-driven experimental designs out in the field to know for sure.” 

And there are only so many researchers and so much funding to go around. It takes lots of work to get solid, dependable answers.

A checkered setwing. Photo by Meghan Cassidy.

Data collected by amateur nature-lovers using community science tools like iNaturalist can help, according to Kieschnick. 

“The data we collect now is addressing questions that haven’t even been asked yet,” he said. People at mothing events or bioblitzes gather information about numbers and kinds of insects they see. When thousands of people report these things, it can help answer questions about how and when these animals emerge, mate and move around or migrate.

We already know some things about insect declines. The Entomological Society of America put on a symposium in 2019 to review some of what was known. Sixty-seven percent of the invertebrates that had been monitored showed average declines of 45 percent in their abundance. It’s not just unusual or rare species that are slipping away; many formerly abundant insects that provide important ecosystem services are declining.

Why are these declines happening? In a paper from the Proceedings of the National Academy of Science, the global threats to insects were described as “death by a thousand cuts.” 

Insects are threatened by many things, such as climate change (with fires on bigger scales, droughts, more intense storms, etc.); urbanization, deforestation and other forms of habitat loss; pollution by chemicals and also disruptions caused by light and sound pollution; pesticides; and non-native plants, animals and pathogens.

Places that have native plants are a key to keeping healthy insect populations. Many insects are adapted to use a narrow range of native plants, maybe just one type. Yuccas and yucca moths have that kind of relationship, in which the yucca is the only food for the moth and in turn the moth is the only pollinator for the yucca. 

Baxter-Slye said, “If a particular insect depends on a host species and we see that host decline, we would expect a decline in that insect species.” 

The relationship between monarch butterflies and milkweed is well-known; the caterpillars depend on milkweed as a food source. 

WHAT WE CAN DO

An eastern tiger swallowtail sips nectar from a thistle. Photo by Meghan Cassidy.

Doing something is important, not just for people living in a rainforest but for us, living here in these biologically important North Texas prairies and woodlands. Here, so many critters live and so many migratory species look for food or rest on their journey.

1. Plant native plants. The first thing we can do to is restore native plants on our property. Organizations such as the Native Plant Society of Texas and its local chapters can show us the “what” and “how” of using native plants and can help homeowners work with homeowners’ associations about the difference between wildscapes and “weeds.”

2. Support blue-green infrastructure. By this I mean, nature-friendly approaches to landscape (green) and water management (blue). For example, a city might plant native plants rather than mowed turfgrass in public spaces or support natural streams and wetlands rather than channelizing water flow.

3. Pitch the poisons. Sometimes there are natural or less damaging methods of pest control that can be used on lawns, trees and crops. When we really do need to use pesticides, we can choose less-damaging ones and use them carefully. Among the pesticides reported to be very problematic are the neonicotinoids, which the Natural Resources Defense Council calls “some of the most deadly pesticides ever created.” Neonicotinoids are applied to plants, seeds and soil where they kill indiscriminately, harmful and beneficial insects alike.

4. Ditch the zapper. Maybe we should re-think bug-zappers. Kieschnick said that these zappers are effective killing tools for some insects but “they don’t zap mosquitos.” Instead, they are zapping a lot of useful insects, including those that serve as food for birds.

5. Use your voice. Informed citizens can take time to speak up to city councils or parks governing boards about making cities healthy places for people and for nature. 

A ringed paper wasp. Photo by Meghan Cassidy.

Baxter-Slye said, “We need to have more people stepping up and talking about what we can do better in municipalities to serve the ecosystem, which in turn will serve us better.” 

We shouldn’t put it off onto future generations, she said. 

“If we wait for the kids to grow up and start making decisions, we’ll be waiting 30 to 40 years.”

What we know so far suggests that we don’t have 30 or 40 years to wait. 

So go mothing, go watch butterflies and dragonflies and pass the word: insects are cool … and necessary!

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