The Loss of Insects and How it Affects Your Garden

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Why should we care about insects? After all, they are just bugs. They sting and bite us and carry diseases. What good do insects do? But the loss of insects will have dramatic effects on the ecosystem - and your garden.

Insects are valuable contributors to the ecology of your garden. Not only do they provide necessary pollination but they are important members of the garden food web. Like plankton in the ocean, they are the foundation of many food chains and provide food for larger insects, birds, and amphibians.

Insects contribute to the US economy. Two entomologists, Mace Vaughan, and John Losey did a study stating insects contribute $57 billion dollars to the economy in terms of helping other valuable species.

Insect populations are plummeting. You may have seen the National Geographic Report that states that 40% of insect species are in decline. What does this have to do with your garden?

Insect Populations Are in Decline

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This chart illustrates declining and threatened insects and vertebrates, according to IUCN data (AFP Photo/Thomas SAINT-CRICQ).

Insects and Gardens

As gardeners, we usually spend a lot of time and effort thinking about how to control or kill insect populations. After all, insects eat our crops, spread diseases and in general, are viewed as adversaries. Why should we care if insect populations are dropping?

Insects help our gardens be productive in many ways.

Most sustainable farmers have a compost pile. Compost adds lots of rich nutrients to the soil and improves your crops. Many insects live in your compost pile and contribute the decomposing process.

Insects naturally help reduce and recycle dead plants and animals by eating them. Sowbugs, centipedes, beetles, and ants are all important players in the compost pile.

Barbara Pleasant, a writer for Mother Earth News and the author of the Home Grown Pantry, has observed fewer beneficial insects and a greater number of insect pests such as squash bugs and Japanese beetles in her Virginia garden.

Fewer beneficial insects mean greater numbers of the insects we don’t want. Lady beetles eat aphids. Parasitic wasps eat whiteflies.


Why Are Insects In Decline?

There is not one smoking gun. Many things contribute to insect decline. Loss of habitat by development and agricultural production. Insecticides used in commercial agriculture to control crop pests as well as cities to control populations such as mosquitoes.

Another factor is invasive species such as the Emerald Ash Borer. Invasive species often “take over” an ecological niche and become dominant.

I love this book by David MacNeal because it really illustrates the importance of insects to the overall ecology. He uses entertaining stories from around the world to share how insects are also an intricate part of cultures as well as the foundation for many food webs.

Insects are Pollinators

No Insects = No Food

Insects are important for pollination in many crops. Without insects, the crops will not develop and produce fruits (the part we eat). Ironically, we destroy insect habitat so that we can plow fields, till our gardens and pasture our livestock.

Specifically, what do insects do in our gardens? Well, most importantly the pollinate plants. Flies, bees and butterflies are all important pollinators. (Birds and bats also provide pollination).

Bee on hat. Photo by Ame Vanorio

Bee on hat. Photo by Ame Vanorio

Many of our favorite foods require insect pollination. Tomatoes, zucchini, apples, melons, coffee, and chocolate. According to the USDA, insects pollinate about thirty-five percent of all food crops. Without them, these plants would not produce.

Some insects feed on other insects that eat our crops. These beneficial insects like lady beetles benefit our gardens by reducing pests without chemicals. By not using chemicals we encourage beneficial insects to thrive in our gardens.

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The Fabulous Bee

A healthy population of bees can improve production. Cornell University did a study that showed strawberry fruit size increased forty percent when actively pollinated.

There are many species of bees. The European Honey bee is the one we are most familiar with. Many gardeners and homesteaders keep bees to meet their pollination needs and because they produce honey.

The mason bee, a native species, is also a very good pollinator. Mason bees are solitary.

Moths and Butterflies

One-third of moth and butterfly species are in danger of going extinct. As in gone forever. Butterflies and moths have a fundamental value. They add intrinsic beauty to our world.

Butterflies and moths are important indicators of the health of our environments. They are very sensitive to chemicals and habitat destruction.

In addition, they pollinate plants and provide “bad” insect control. You want them in your garden – most of the time. I will admit there may be a few species you want to discourage such as the cabbage moth.

The good news is those moths and many others are food for many other species. Bats, frogs, and birds all eat lots of butterflies and moths. So they are important in many ways.

I Want Insects in My Garden!

I am so glad to hear you say this. So many people say that they want to support insects but are unsure of how to go about it. Supporting insects is easy and does not cost much money.

Plant an insect habitat garden

Sometimes we get so focused on growing vegetables and fruits to meet our food needs we forget to appreciate what is just pretty. Growing flowers is a great way to support insects. In addition, they are attractive and make a wonderful focal point in our landscape.

Flowers that make great pollinators include yarrow, sweet alyssum, and zinnias.

Don’t mow everything

I have neighbors that are obsessed with mowing. The property is a recreational piece but they keep the front field mowed to about three inches. I, on the other hand, go to the other extreme. I don’t mow or I mow in selective swaths.

I will mow my fields very selectively. In one field I have a large grouping of milkweed that the monarchs love. In another area, I have a lot of sunflowers and thistles that provides fall seeds for all my finches. It is important for me to provide that habitat.

Many field flowers and “weeds” are great for attracting pollinators. I have seven species of butterflies that inhabit my field. Not only do they come and provide garden work but they are a beautiful and entertaining insect to watch.

Encourage bees

There are numerous types of bees including many native bees that do not produce honey. Native bees gather pollen and nectar and take it home to feed their brood. They typically only travel about a half mile from their nest to gather food. This means that improving bee habitat can have a direct impact on your garden. In addition, native bees pollinate trees and wildflowers which in turn provide food for wildlife.

“Being” a beekeeper is the most obvious way of helping bees and receiving the added benefit of harvesting honey. A beekeeper encourages their bees by gardening sustainably and planting crops that the bees like to eat. This may be vegetables or fruits but can also mean locust trees and field flowers.


The bee hives at Fox Run Environmental Education Center

The bee hives at Fox Run Environmental Education Center

You can purchase bee homes to attract species such as Mason bees. Mason bees are especially good pollinators of fruit trees such as apples, cherries, and plums. Mason bees are solitary and live in cavities.

The fat and friendly bumble bee enjoys tomatoes, eggplants, and peppers and will help you reap a delicious harvest. Bumblebees live in colonies, often in underground holes dug by rodents.

Those pesky carpenter bees are not just “eating” your woodwork. They are actually excellent pollinators of beans and berries. Carpenter bees, like the mason bee, live in cavities. You can provide cavity housing for mason, carpenter, and bumblebees like this one.

Ame Vanorio is the founder and director of Fox Run Environmental Education Center. We strive to provide education in the areas of alternative energy, organic gardening and wildlife conservation. We are a state licensed wildlife rehabilitation facility.