Why Do Insects Have to Be Either ‘Beneficial’ or ‘Pests’?

I spend a lot of my time introducing people to insect species –  showing them a bug or caterpillar they’ve never seen before and/or revealing fascinating tidbits about that animal’s life.  Many times, after I share my story I’m met with the question, “So, is it a beneficial insect then?”

The term ‘beneficial insect’ has always bothered me.  The implication, of course, is that an insect either plays a role that directly helps us or it is a pest.  If it helps us, great!  If not, we squish it.  (Even if it helps us, we still might squish it, but we’ll feel a little bad about it.)

I don’t want to have to defend my favorite insect (camouflaged looper) from people who question whether it’s ‘beneficial’ or not.

The truth, of course, is that every insect species (along with other invertebrates, plants, microorganisms, and even vertebrates like birds, reptiles and mammals) is part of a complex web of interacting communities and ecosystems.  Every (native) species plays an integral role that would be missed if it were gone. 

Pollinators are getting a lot of deserved respect and attention these days, but that’s just one of many important roles played by insects.  For example, herbivores eat the leaves and stems of plants, granivores feed on seeds, and predators, parasites, and parasitoids feed on those herbivores and granivores.  Each helps keep populations of other species in check, and many rely upon each other for food or have otherwise developed complementary relationships that are mutually beneficial.  In years when some insect populations are down, other species can fill in for them, keeping important roles filled.  The whole system relies upon a broad diversity of species and a redundancy of contributions that ensures all necessary jobs are always filled.

These sunflowers aren’t being ‘attacked’ by insect pests, they are providing critical resources to insects that play vital roles in ecosystems. This is what’s supposed to happen. Plants that aren’t ‘damaged’ by insects are not providing any value to their surroundings.

Because a diversity of insects is so integral to the resilience and function of ecosystems, it seems obvious that we should do everything we can to support all those species, right?  So why are we so picky about which insects we celebrate?  More importantly, within our yards and gardens, why are we so insistent upon categorizing insects as either beneficial or pests?

Trying to keep insects away is backward thinking.  We should be designing our private spaces in ways that provide food and habitat for the species that keep the earth humming along.  The recent focus on pollinators has led to an increase in the use of native wildflowers and an attempt to make sure there are always a few flower species blooming across the seasons.  That’s terrific, and people are right to revel in the sight of bees, butterflies, and other insects harvesting pollen and nectar from those plants.  Many people have also planted milkweed in their yards to give monarchs a place to lay eggs so their caterpillars can have something to eat.  Again, excellent.

So, why are we ok with insects eating pollen from flowers, but not chewing on leaves?  Or why do we celebrate monarch caterpillars feeding on milkweed plants but reach for soapy water sprays (or worse) when other insects dare to make holes in the leaves, stems, or petals of plants?  What are those plants for anyway?  Are they really just for decoration?  If so, there are much less time intensive ways to decorate around your house.  Garden gnomes, for example.  There’s very little maintenance involved in statuary.

We happily plant milkweed so monarch caterpillars can ravage their leaves but tend to be bothered by other kinds of caterpillars chewing on yard/garden plants, including whatever the bottom caterpillar here is. I bet the second caterpillar is a more important food source for birds and other creatures (if nothing else, because it doesn’t taste like milkweed’s toxic latex).

Those of us who are lucky enough to influence plant and animal communities on small parcels of land should feel an obligation to use those parcels for good.  Plantings for pollinators is a good first step, but why can’t we apply that intent more broadly?  The presence and diversity of insects should be a measure of success, not a cause for concern. 

Now, because you’re already thinking it, I agree that food production is a special case.  If you’re trying to grow your own food, I understand the frustration of losing a crop to insects.  However, there’s a big difference between ‘cosmetic damage’ and total destruction.  Kale leaves with holes in them are still perfectly edible, and losing a few zucchini plants to vine borers – let’s be honest – often turns out to be a blessing later in the summer when we’re buried by the mountains of zucchini produced by the surviving plants.

As Kim, the gardener in our household, says, “If you think you’re going to have complete control of everything in a garden, you’re just setting yourself up for disappointment.”  A big part of gardening is watching and learning from what happens in a dynamic environment.  That process can be just as important and enjoyable as harvesting and eating tomatoes or green beans. 

“Damaged” produce from our garden, including collards, kale, basil, and tomatoes. All have evidence of feeding by insects, but we are still getting plenty of food from each of these crops.

Every gardener has to make their own decisions about when/if to control insects on their crops, but some degree of tolerance should be part of that process.  Few of us rely on the food from our gardens for our survival, after all.  Viewing gardens as part of an ecosystem, rather than as a machine for creating perfect food, makes gardening a much more pleasant experience.

Now, having said that, there are some truly invasive insects that we should be treating as such.  Japanese beetles have recently entered our area of the country, and they’re no joke.  Other non-native insects like gypsy moth, spotted lantern fly, and emerald ash borer cause lots of damage too.  These insects are largely problematic because they haven’t been part of the ecosystem very long and aren’t part of the checks and balances.  Most native insects have predators, parasites and parasitoids, as well as disease organisms, that target them and suppress their populations.  Invaders work outside that system of control. 

Japanese beetles are spreading quickly across the U.S. and don’t seem to have an array of other species that act to suppress their populations.

Some of those invasive species came to the U.S. accidentally, but we’ve been our own worst enemy in other cases.  Asian ladybugs and Chinese praying mantises, for example, were both introduced as ‘beneficial insects’ before becoming established as invasive species.  Not only do we insist upon categorizing our insects as either ‘beneficial’ or ‘pests’, we go looking abroad for new species to tip the scales against those pesky insects that dare eat our plants.

The vast majority of insects in our yards, though, are native species with important contributions to the world around us.  If you’re fortunate enough to have a house with yard and/or garden, please consider your options carefully.  Why do you enjoy having that yard?  If the answer is that you just want it to look good for the neighbors, you’re missing out on a tremendous source of potential joy. 

Watching and admiring the intricate relationships between insects, plants, and other animals is endlessly fascinating.  In addition, you can make significant contributions to conservation in your yard, simply by aiming your efforts toward providing resources for nature.  Seeing birds at feeders or bees on flowers are only two examples of ways in which you can feel good about your yard’s impact.  In addition, while your plot of land might be small, collections of yards quickly add up to areas of habitat that matter in a very reason sense.

I loved learning this spring that false milkweed bugs feed on false sunflower seeds (shown here). I learned that because it was happening in my backyard prairie garden.

If you lean into the idea that you’re creating habitat for as many species as you can, success comes easily.  Instead of worrying about what’s eating your plants, you’ll start to notice which plants attract the most caterpillars or grasshoppers.  Then, you’ll notice where the crab spiders or assassin bugs like to hang out, trying to take advantage of that abundance of prey.  Birds will appear too, catching those insects to feed their families or fuel their migration flights.  A complex mass of dynamic interactions will be taking place literally in your back yard – and you’ll have a front row seat. 

Can we please stop trying to categorize insects as either beneficial or pests?  Let’s set ourselves up as providers instead of protectors.  A yard can be a place to relax and enjoy your own piece of the world, so why not make that piece as interesting as possible – and help out the world at the same time?  

And yes, garden gnomes are welcome too.

This entry was posted in Uncategorized and tagged , , , by Chris Helzer. Bookmark the permalink.

About Chris Helzer

Chris Helzer is the Director of Science for The Nature Conservancy in Nebraska. His main role is to evaluate and capture lessons from the Conservancy’s land management and restoration work and then share those lessons with other landowners – both private and public. In addition, Chris works to raise awareness about the importance of prairies and their conservation through his writing, photography, and presentations to various groups. Chris is also the author of "The Ecology and Management of Prairies in the Central United States", published by the University of Iowa Press. He lives in Aurora, Nebraska with his wife Kim and their children.

28 thoughts on “Why Do Insects Have to Be Either ‘Beneficial’ or ‘Pests’?

  1. If only we could train the Japanese Beatles. I have seen them do tremendous damage to Purple Loosestrife in my area the last couple of years. Great photos and article.

  2. I own a retail native plant nursery in Indiana. Recently someone purchased a native viburnum but expressed extreme concern about a few holes in the leaves. My response? Yes, isn’t that great! That’s why we plant natives.

    It is a major re-education effort.

  3. Thanks, Chris, what a wonderful way to help us think of our personal spaces—and our insects–differently! A planter on a deck or sidewalk, a yard, community garden, a park, a Prairie– all can be Patches in the Quilt of Nature!
    Kind Regards, Ruth 🌻🦋🌾

  4. Are we a beneficial species in our environment? When we think about “fighting” an
    insect we should remember that we simply don’t know much about what IS important. History is littered with our mistakes about how to manage our environment. I’m with Kim, we have much to learn. Great article.

  5. So true, Chris! Such a complex world. And speaking of caterpillars, I’ve been reading a book of essays by the naturalist Bernd Heinrich and was blown away by one called “Reading Tree Leaves” in which Heinrich explains some amazing tricks caterpillars use to avoid being noticed by birds. Astounding, really.

    As always, thanks for what you do and how well you communicate.

    Here’s a link to Heinrich’s essay in case you have time for it: (https://books.google.com/books?id=S6_qDwAAQBAJ&pg=PT49&lpg=PT49&dq=%22reading+tree+leaves%22+bernd+heinrich&source=bl&ots=xpVGPVS6AQ&sig=ACfU3U04iwOYKTdBhangCHPFa2RXT4Xsug&hl=en&sa=X&ved=2ahUKEwi8kOPMs7PzAhX8k2oFHUMmAwEQ6AF6BAglEAM#v=onepage&q=%22reading%20tree%20leaves%22%20bernd%20heinrich&f=false)

  6. Some of your best blogs are the ones that are ‘outside the box.’ This is one. Another was a cautionary approach to fire. Keeps us thinking — thank you for that.

  7. YES YES YES! So true, every word of it. I rejoice when I see there are holes in my plant leaves. That means someone is getting some value from them. Thank for this article.

  8. YES YES YES! So true, every word of it. I rejoice when I see there are holes in my plant leaves. That means someone is getting some value from them. Thank for this article.

  9. Chris:
    Great post.
    It’s amazing to me that we humans still have to categorize creatures (including plants) in this way.

    I would disagree with this part of one caption: ” Plants that aren’t ‘damaged’ by insects are not providing any value to their surroundings.” In addition to their role in the hydrosphere and atmosphere, they will be decomposed by something–bacteria, fungi, etc. and help diversify and replenish the soil–the very basis of trying to shift agriculture to perennials.

    Keep up the good work.

  10. Refreshing perspective that hit home. I walked by a lovely deep pink Hibiscus moscheutos today whose leaves have suddenly been turned to lace by tiny caterpillars. I’ll do my research and identify the culprits but then I’ll stay in the background as a passionate observer, enjoying the bigger picture.

  11. Well said, Chris, as you can probably tell from the many positive responses you’ve received. (Maybe you should have waited a little longer to close your survey of blog readers!) Thank you for speaking up against judging (native) insects and all other living things in our environment as being “beneficial or pests.” The world needs more cheerleaders for the environment as a whole and not just as we might prefer in our own backyards.

    In the Midwest, residents in urban and suburban areas often consider rabbits to be the bane of their existence. It is my understanding that in some of the Eastern states the Eastern Cottontail has completely disappeared or is in sharp decline. Now there is an effort by scientists to raise these former “pests” to restock the environment — at no small cost of time, effort, and financial resources. In nature, rabbits reproduce prodigiously (they are, after all, a prey species) but apparently it is not quite so simple when humans are attempting to raise them, but as you say, “Every (native) species plays an integral role that would be missed if it were gone.”

    In a former post (Purist or Pragmatist) you reminded us that “We (people) have turned out to be unreliable managers of nature.” Your current eloquent essay encourages us to be open-minded and reminds us that we can do more for the environment that we love. Please keep up the good work!

    • Aw, thanks Chris. I really appreciate that. I’d not heard that cottontails are disappearing to the east. We still seem to have plenty here. I would think they’d have to be a pretty important prey species – as well as cute!

    • Chris, I hadn’t heard about the Eastern Cottontail issues either. I wonder how much of that problem is attributed to outdoor cats? Uggghhh!! Talk about an ‘invasive species’!

  12. Very cool blog post and excellent points. We have planted our little 23-acre plot here with native plants and have seen a dizzying array of different bugs. So many that I often have to do a search on the internet to identify some of them.
    My friends laughed at me this season when I decided to plant 9 tomato plants, intending to let the hornworms have only 3 of them. Well, the hornworms showed me. They multiplied to over 100 of them (turns out they were ‘tobacco hornworms’), and at one point, I had to remove the majority of them. Now that I’ve collected what I wanted though, they are once again enjoying a feast.
    It truly is to see everything in nature, working like a finely tuned orchestra.
    Loved this post!

  13. Pingback: Some Ichneumonids | Backyard and Beyond

  14. Several years ago I bought a framed artwork of a spruce budworm caterpillar and adult, for reasons I had not fully articulated at the time but which are wonderfully expressed here. This summer I’ve enjoyed taking a closer look at things like leaf mines and leafcutter bee handiwork (tarsiwork/mandiblework?). I will share this. Thank you!

  15. Pingback: Beyond ‘Beneficial Insects’ or ‘Pests’: Aiming for Diversity Instead – The Wildlife Habitat Project

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