I’ve always been fascinated by insects. When I was little, my father used to take us on nature walks with our butterfly nets, collecting jars, magnifying glasses, and guidebooks to learn about the insects in our area. I immediately fell in love with all things invertebrate–iridescent beetles, camouflaged walking sticks (they look like twigs!), buzzy cicadas, and especially butterflies: their fleshy caterpillars, the intricate patterns and colors on their wings, and the way they fluttered from wildflower to wildflower. My kind of heaven.
It wasn’t until later that I learned the essential role insects play in the planetary ecosystem as pollinators and distributors of seeds. Without them, life as we know it wouldn’t exist. But insects, like birds, are suffering record declines due in large part to habitat loss, pesticide use, and climate change. I want to do what I can to help these creatures who have fascinated me since I was a child, so I reached out to Matthew Shepherd, conservationist and director of outreach and education at the Xerces Society, to learn more about some of the amazing insects we can find in our gardens and what we all can do help them. Here’s what he said:
Q: What are “beneficial insects”?
A: The term beneficial insects is used describe a particular group of insects that is somehow useful to us. Typically, we’re talking about pest control for our farms or our gardens. But there are so many other insects that we’re not noticing that bring benefits to us, like those that decompose vegetation (like getting rid of leaves) or dispose of dead animals and all that kind of stuff. Here are some great beneficials to look out for:
Lady beetles. The first one we think of when we talk about beneficial insects is the native lady beetle. They don’t sting or harm humans, and they are amazing predators in both their adult and larvae forms, especially of aphids and scale insects. They’re not to be confused with the multicolored lady beetle, which is not native and overwinters in sheltered places like our homes. You won’t find the native species in your homes.
Lacewings. All insects are beautiful to me, but lacewings are particularly attractive. They have transparent wings with such a fine pattern on them and metallic, golden eyes. They’ll munch their way through aphids, mealy bugs, and caterpillars. Their larvae look like tiny little crocodiles with jaws that are kind of curved like a sickle on each side. They practically inhale their prey. They’re only about a half-inch long and will run around your hand without harming you, but watch out if you’re an aphid.
Fireflies. We tend to think of fireflies just as a beautiful and magical part of summer evenings. But they are also savage predators. They’ll eat soft-bodied insects and even earthworms and slugs. Give them welcoming places to live in your yard. [To learn more about firefly conservation, click here]
Wasps. Predatory wasps are so valuable. I think yellowjackets give all wasps a bad rap, but even yellowjackets are incredibly useful and beneficial to have around because they’re gathering so many of these other insects that we think of as pests. But there are so many other wasps. Many are solitary, like the majority of our native bees. A single female will make a nest by tunneling into the dirt. She’ll occupy this small cavity and gather insects and other small prey to take back to her nest to feed her offspring.
Predatory wasps typically have a preferred prey. Some will specialize on things like caterpillars, stink bugs, tree crickets, grasshoppers, flies, or spiders. There’s even a wasp that specializes on tarantulas if you’re in the desert southwest. These wasps might seem fearsome to their prey, but they’re going to ignore you. You can get up close and watch a wasp hunting around on a flower or roaming around the ground looking for a spider. It’s not going to be a threat to you.
Q: What can we do to help insects at home?
A: If you care about birds, bees, and butterflies, create a garden that will support them. About 96 percent of land birds feed their offspring insects and that’s primarily caterpillars. If you want to have those beautiful adult butterflies, you have to support the entire life cycle. And that means having plants that their caterpillars can eat.
Don’t use pesticides in your yards and don’t buy plants at nurseries that are treated with them. First and foremost, avoid all pesticides. Our, modern pesticides taint nectar and pollen and some can even make the entire plant tissue toxic. This is especially important for insects like leaf cutter bees and other closely related ones that take leaf pieces back to their nest. Take the time and the courage to ask your nursery about what their plants have been treated with. Xerces has been building an effort that we’re calling Bee-safe Nursery plants, to encourage people to let their nurseries know that they want pesticide-free plants. We want people to know what they’re buying so they can make informed decisions on where to shop.
Accept a little nibbling. If you want pollinators in your garden, you have to accept that your plants are going to get chewed. If you want to have those beautiful adult butterflies, you must support the entire life cycle, and that means having plants that their caterpillars can eat.
Leave the leaves. Leaving leaf matter in your garden for insects to overwinter is a way of helping by doing less. This web page has information and links to more resources about leaves and keeping stems for bee nesting.
Grow native plants. Studies have shown that native plants support more native insects. For example, Doug Tallamy at University of Delaware has shown that moth and butterfly abundance and diversity are hugely greater when you have native plants. There are also studies about native bees with similar results: the more native plants you grow, the more diversity and abundance of native bees. I will always encourage people to make native plants the core of their gardens because you can create fabulously beautiful ones with them. But you can also grow other varieties alongside the natives. I’m British and grew up gardening alongside my mother. There was always lavender growing in her garden, so I have an emotional tie it. I plant English and Spanish lavender in my garden, even though it’s not native because it’s beautiful, smells glorious, and supports insects. I also have purple coneflowers and black-eyed Susans, which are not native to where I live in Oregon. They both are great sources of nectar and pollen, and I know that the native bees will nest in the stems. It’s ok to have some non-native plants as a component in your landscapes, but native plants are necessary.
Take milkweed and monarch butterflies, for example. Monarch caterpillars need milkweed to feed and grow. Adult butterflies need nectar to fuel their flight and to breed. If we plant the right type of milkweeds and nectar plants, we’ll be supporting the entire life cycle of the monarch. Everything we do in our gardens can help because monarchs migrate. If a monarch is flying over your garden and it sees the good stuff, it will come down. What we do in our garden connects with what our neighbors are doing down the block or what people are doing in the next town or the next state. The monarch is one of these incredible insects that kind of physically and emotionally connects all of us. What we do in our gardens can really have an impact. If you have questions, I always recommend that people reach out to their local county Master Gardeners. In my experience, they are knowledgeable and wonderfully helpful people!
Xerces has also just released a new series of regional lists that will help people find good plants for their garden: Native plants for pollinators & beneficial insects.
Q: Any success stories on an insect rebounding?
A: Scientists had thought that the Fender’s Blue butterfly, from Oregon’s Willamette Valley, had gone extinct in the 1930s. But in the late 1980s, it was rediscovered by a 12-year-old boy. He didn’t know what he had, but he knew he hadn’t seen it before. Then the next year, an entomologist from Oregon State University found some and identified them as Fender’s blue, a tiny blue butterfly that’s about an inch across, whose habitat is prairie grasslands, which has now mostly been converted to agriculture and development.
Fender’s Blue had survived all these years on roadside verges and small scraps of prairie vegetation in and around fields and on the edges of wood.
About a decade later in 2000, it officially became classified as an endangered species under the US Endangered Species Act. When a species becomes endangered, it puts limits on what you can do to your land, and it also unlocks funding to support habitat management and research needed to inform conservation work. Today, the Fender’s Blue is no longer officially endangered, but has been upgraded to threatened. It’s a step in the right direction. It’s also a great example of one discovery by a boy who launched all of this–that’s a kind of community science at its most powerful.
Q: Why is community science important?
A: Community science is great. It helps both conservation organizations and scientists because we can’t be in all the right places all the time to collect observations. The reason why we know which plants are good for the rusty patched bee, for example, is because of observations from the community. Here are some projects to join:
- Firefly Atlas tracks and conserves fireflies.
- Journey North focuses on species migration.
- iNaturalist or Seek by iNaturalist helps you share your observations of flora and fauna.
For more on insects in the garden, see:
- Monarch Butterflies Are Nearing Extinction: 5 Ways to Help
- Buzz Worthy: How to Help Honeybees Through Winter, With Island Bee Project in Brooklyn
- 10 Essential Insects You Need in the Garden