Mosquitoes can be dangerous. Flies are annoying. Cockroaches are disgusting.
But not all bugs are bad. On the contrary, many types of insects are essential to our existence.
And some, including the bees that pollinate our food crops, are in danger.
According to the Daily Climate, “every year there are slightly fewer butterflies, fewer bumblebees — fewer of almost all the myriad little beasts that make the world go round.”
A recent study found that insect populations on land are decreasing by 0.92 percent per year. That would mean 24% fewer insects in 30 years. Some scientists fear this decline could damage ecosystems beyond the point of recovery.
A Canadian study in 2020 found that North American bumblebee populations have nearly halved, and European bumblebees decreased by 17%.
So what can we do to preserve beneficial insects, even if we are not scientists or agronomists?
We asked Tamar Keasar, a professor of insect ecology and behavior at the Department of Biology and the Environment on the Oranim campus of the University of Haifa.
Her lab studies pollination ecology and biological control in Israel’s agricultural and natural areas.
Keasar suggests eight simple actions you take in and around your own home. Share these tips with family, friends and neighbors, to conserve beneficial insects near our homes, and to enjoy their amazing ecological services.
- Provide nesting places for bees
“We are all familiar with honeybees. But there are many other kinds of bees that help pollinate our crops and wildflowers. Israel has more than a thousand species of wild bees,” Keasar says.
“Unlike honeybees, most wild bees do not live in colonies. Instead, each female bee makes her own nest where she lays eggs. Some wild bees nest in the soil, and others nest within dry twigs, old walls and even snail shells,” she explains.
“By exposing some sunny, dry ground in your backyard, you can create a bee-friendly nesting area. Or you can set up bunches of reeds or even drinking straws to create a ‘bee hotel’ in any outdoor area.”
- Treat swarms gently
“A honeybee swarm may appear near your home or in your garden. This happens when large groups of bees leave the hive where they grew up, and search for a new place to settle. Don’t panic! While you probably don’t want the bees to remain next to your home, many beekeepers would love to have them,” says Keasar.
Contact your local beekeepers’ association or bee rescue volunteers, who know how to capture and remove the swarm carefully.
- Grow plants for bees
“Bees get their entire nutrition from flowers. In hot and dry countries such as Israel, flowering plants are rare in the summer and fall, so bees may go hungry. But you can help,” says Keasar.
“By growing summer- and autumn-flowering plants, you can tide bees over these difficult seasons. Local plants with nectar- and pollen-rich flowers are best. If you live in Israel, consider planting a carob or a tamarisk tree.”
- Grow a variety of plants for parasitoid wasps
Parasitoid wasps are tiny insects — most are smaller than 1/16th of an inch, or 2 millimeters – and they do not sting humans.
“Despite being very diverse and abundant, we often don’t notice parasitoids because of their small size,” says Keasar.
“Yet parasitoids are important beneficial insects because they help control pests that infest our food crops and gardens. The young stages of parasitoids wasps feed on other insects, such as aphids or moths — many of which are crop pests,” she says.
“The adults, on the other hand, often eat flower nectar and this improves their survival and reproduction. Unlike bees, parasitoids usually feed from small shallow flowers that they can access with their tiny mouthparts. They will thrive on a small bed of flowering buckwheat or coriander in your backyard or balcony.”
- Diversify your garden
“Humans need a varied diet to obtain all the nutrients they need, and so do beneficial insects. For example, bees need to feed on pollen from different plants to achieve the correct balance between different types of fatty acids,” Keasar explains.
While many modern farms have huge fields dominated by a single crop, you can provide a healthier balanced diet for bees and parasitoids by growing mixtures of different flowers in your garden or on your balcony.
- Monitor before you spray
We often use pesticides to control nuisance insects such as cockroaches, mosquitoes or ants in our homes and gardens. Sometimes, we use insecticides as a prevention strategy before we even see these pests at home.
Keasar advises not to do this.
“Insecticides carry health hazards for humans and pets; they are expensive; and they harm beneficial insects. ‘Good bugs’ may suffer from insecticides through lower survival, reduced fertility, or impairment of flight, learning and navigation,” she explains.
“To reduce these hazards, look out for the household pests, and spray to control them only after they’ve actually infested your home.”
- Use selective insecticides
When you do spray, choose a bug killer targeted to the specific insect you’re trying to get rid of, rather than a broad-range product.
“Using such selective insecticides against household pests carries lower risk for bees, parasitoids and other beneficial insects. Look for, and avoid, insecticides labeled as highly toxic to bees, wildlife and aquatic invertebrates.”
- If you like butterflies…
In the United States, the iconic black-and-orange monarch butterfly is declining in numbers to the point where it may be declared an endangered species.
But Keasar explains that butterflies generally aren’t considered beneficial because their larvae are serious agricultural crop pests. And the adults are only marginally important as pollinators.
However, if you are interested in conserving butterflies for their beauty, the steps you take can have the side effect of preserving other insects that may be more beneficial or more threatened, but less pretty and charismatic.
The US Fish & Wildlife Service suggests planning a “pollinator garden” with plants that bloom in different seasons and can be placed in fully or partially sunny areas. Native milkweed is a particular favorite of monarch butterflies.