Buying ladybugs for biological control of pests can contribute to depleting the ladybug population in the wild and raises other concerns as well. Meanwhile, non-native ladybugs do the same valuable work — eating aphids and other pests that harm crops — but are often cast in a bad light anyway. My guest in this week’s encore, Dr. Kaitlin Stack Whitney, an environmental studies scholar as well as a home gardener, explains that non-native insects don’t always deserve their bad rap.
Kaitlin earned a bachelor’s in international agriculture and rural development from Cornell University and a doctorate in zoology from University of Wisconsin-Madison. She is an assistant professor in the Department of Science, Technology, and Society at the Rochester Institute of Technology College of Liberal Arts in upstate New York, where she also runs the Stack / Whitney Entomology, Environment and Technology Col(LAB)oratory. Her expertise includes entomology — the study of insects — and science studies — the study of how science is done and how science is a human endeavor.
Kaitlin Stack Whitney, Ph.D. is an environmental studies professor who asks challenging questions about our relationships with plants and insects. (Photo Courtesy of Kaitlin Stack Whitney)
“My background is looking at the environment, but also making sure that we’re looking at ways of understanding and exploring the environment that are beyond the sciences,” Kaitlin says.
Kaitlin wrote a 2023 essay for the science studies journal Catalyst: Feminism, Theory, and Technoscience that explores problems with purchasing native ladybugs for biological control of garden pests and questions why non-native ladybugs, which also provide natural pest control, are often hated.
People purchase ladybugs because they want to do something helpful, she says — choosing beneficial predatory insects over using pesticides. But what they don’t realize, she says, is that the wild-caught ladybug trade depletes ladybugs from the area where they are being harvested.
“We can think critically about why it is that we are willing to spend money on a native ladybug, but why wouldn’t we just promote the ladybugs that are already around us that can get us that pest control?” Kaitlin says.
She notes that pest-eating ladybugs make for great biological control because they are mobile and are generalist predators — meaning they eat a lot of different things. “That means that if they eat all your aphids, then they can go on to moving and eating something else that’s around,” she says.
Read on for a condensed version of our conversation, or you can see the show notes from the original airing for the unabridged version.
‘Good’ and ‘Bad’ Insects
Kaitlin set out to explore why people call some insects “good” and some insects “bad.”
“As gardeners, when we have insects in our garden that are eating the plants that we want, that can feel really personal,” she says.
Gardeners tend to describe insects munching on plants as “attacking.” She encourages gardeners to reflect on using “violent, militarized language” when talking about insects that need to eat plants to live.
“They want to eat that plant and we want to eat that plant,” she says. “We actually have something in common, right? It doesn’t necessarily make us enemies.”
Your reason for gardening will also influence how you feel about insect activity, Kaitlin points out. If you are growing vegetables and flowers for the joy that growing brings, you likely have different feelings than someone who is growing plants for food security and subsistence.
When the damage is only aesthetic, like in the case of an ornamental garden, how much damage is tolerable comes down to the personal preference of the gardener rather than the detriment to the plants.
The Problem With Purchasing Ladybugs for Pest Control
Kaitlin is on board with harnessing the power of ladybugs as an alternative to using pesticides for pest control. But she finds fault in buying ladybugs.
She points out that studies have shown that a purchased beneficial insect is likely to fly off to someplace else upon its release — immediately or within two days. And she says the timing can be sensitive and tricky. If a gardener orders ladybugs after noticing a big pest outbreak, the ladybugs will likely arrive too late to prevent the pest damage. Either way, it was not the best use of the gardener’s money.
Kaitlin says buying ladybugs for pest control is working in the same framework as buying a chemical spray for pest control. Neither is a one-and-done solution, but rather a stop-gap that may have unintentional consequences.
Some insects are reared for pest control in facilities called insectaries. However, the most popular ladybug sold for biological control, the convergent lady beetle (Hippodamia convergens) is generally harvested from the wild in California.
Kaitlin says to think of ladybug harvesting as a fishery. If too many fish are taken away, the population won’t be able to sustain itself and may collapse. If too many convergent lady beetles are harvested, there may not be enough left to control pest insects in the wild.
“It’s important to remember that when we’re gardening, we’re often just thinking about our little garden, right? But really at the end of the day, everything is connected,” Kaitlin says.
A Hippodamia convergens specimen. Known as the convergent ladybug, it is harvested in the wild in California and sold for biological control of garden and greenhouse pests.
(Photo Courtesy of Kaitlin Stack Whitney)
Better Common Names
The Entomological Society of America has started the Better Common Names Project to acknowledge that many common names formally adopted for insects contain derogatory terms, include inappropriate geographic references and “inappropriately disregard what the insect might be called by native communities.”
“A lot of times the insects that we are villainizing, we are putting the country or continent of origin in the name,” Kaitlin says, “and this is part of a long and often bad history of conflating people and animals from other places in a way that can be dehumanizing to people and is often xenophobic.”
The project seeks to adopt better common names with the help of community input. For example, Lymantria dispar, formerly known as the “gypsy moth,” is now called the “spongy moth.”
Harmonia axyridis is the scientific name of a ladybug known in the United States as the multicolored Asian lady beetle — a name currently accepted by the Entomological Society of America. In the United Kingdom, it is better known as the harlequin ladybird. Kaitlin makes a conscious choice not to use the common name that includes a continent of origin, and prefers harlequin.
Wildlife and plants from other places are often talked about in ways that can be demonizing, Kaitlin says. “There are documented cases where people from other places and immigrants were conflated with insects from those places in ways that villainize both people and insects.”
Harmonia axyridis, known as the multicolored Asian lady beetle and as the harlequin ladybird. (Photo Credit: Amy Prentice)
Non-Native Doesn’t Always Equal Bad
Gardeners often hear messages — including on “The joegardener Show” podcast — that native plants and native insects are good. Kaitlin says people assume that the opposite must also be true.
“We get lots of benefits from insects and plants that are not considered to be native, as in they’re not originally from here,” she says.
The honeybee is the epitome of an insect that is not from North America but is beneficial and beloved.
“Honeybees are not, quote, unquote, from here, but they’re really well adapted to pollinate lots of plants that are from the same part of the world that they are, which is why they make great pollinators of apple trees,” Kaitlin says.
But, she notes, having too many honeybees around can have a negative impact on native bees and other pollinators.
Promoting Ladybugs in Gardens
Kaitlin says it’s important for gardeners to recognize that they can have an impact and be good stewards of the wildlife moving through their gardens. When it comes to ladybugs, the species gardeners come across may not be the species they were most hoping to find, but those species still provide an opportunity for conservation.
Because ladybugs have coloration and patterns that are different from species to species, studying them in your own garden makes for an easy and fun activity. And once you identify the ladybug species that come around your garden, it’s easier to engage in conservation biological control.
Conservation biological control means promoting and attracting ladybugs and other predatory beneficial insects that are already in the area — rather than purchasing biological control insects that were raised in an insectary or harvested from the wild.
You may not recognize this insect, but it’s actually the larval stage of Coccinella septempunctata, the seven-spotted lady beetle. If you look closely, you can see that it’s devouring a green peach aphid. Ladybugs are voracious eaters at this stage and a natural enemy of aphids and other sap-feeding insects. (photo: Amy Prentice)
Harmonia axyridis Are Not All That Different From Native Ladybugs
Kaitlin has a stand-out memory from a college trip during which she and her fellow students were admiring a ladybug that had landed on the side of a van when their professor walked up and smashed the ladybug with his open hand. “That’s invasive,” he said as he walked away.
That moment really stuck with her because up until then, she never thought any ladybugs were labeled “invasive.” She says that the smashed ladybug was likely Harmonia axyridis, the harlequin ladybug, which is often viewed as a pest due to its habit of gathering in large groups — a behavior called aggregation — inside houses or under shingles for winter shelter. And some people are allergic to ladybug bites, so they really don’t want ladybugs inside their houses.
All ladybugs bite, not just harlequin ladybugs, and a bite from any species of ladybug can cause an allergic reaction, Kaitlin says. She notes this is something that ladybugs deemed “good” and ladybugs deemed “bad” have in common. And regardless of whether they are native or non-native, ladybugs don’t transmit diseases to humans, the way that mosquitoes or ticks can.
Being generalist predators is what makes ladybugs so good at pest control, but it is also one of the reasons why some see harlequin ladybugs as a problem. Not only do harlequin ladybugs eat aphids and other soft-bodied insect pests, they also eat the larvae of other ladybug species — including the native species we may be trying to promote in our gardens.
Kaitlin says that, according to the most recent survey, completed in 2007, there have been 179 species of ladybugs released in the United States and of those, 27 have become established.
“Some of that same data found there was no difference in the number of ladybugs overall when you’re comparing before and after the harlequin ladybug becoming established,” she says. “So I think that anytime we’re talking about new life in an ecosystem and the impacts it might have, those are definitely important questions.”
An insect survey will likely uncover both native and non-native insects. (Photo Courtesy of Kaitlin Stack Whitney)
If you haven’t already listened to my conversation with Dr. Kaitlin Stack Whitney on buying ladybugs, native and non-native ladybugs, insect conservation and more, you can scroll to the top of the page and click the Play icon in the green bar under the page title to do so now.
Have you tried buying ladybugs for your garden? What was your experience? Let us know in the comments below.
Links & Resources
Some product links in this guide are affiliate links. See full disclosure below.
Episode 049: When Good Bugs Eat Bad Bugs: The Business of Beneficial Insects
Episode 050: Organic Pest Control: Beneficial Insects And Beyond
Episode 067: Predatory Beneficial Insects: Feared Foes of Garden Pests, Pt. 1
Episode 068: Top Predatory Beneficial Insects and How to Attract Them
Episode 195: Identifying and Controlling Garden Pests Organically
Episode 327: The Nuances of Native and Non-Native Ladybugs and Other Insects
joegardener Blog: Understanding the Ladybug Lifecycle
joegardener Blog: How to Improve Your Soil: 3 Simple Steps for Making Any Soil Better
The Best of the Must-Haves™ holiday gift guide
joegardener Online Gardening Academy™: Popular courses on gardening fundamentals; managing pests, diseases & weeds; seed starting and more.
joegardener Online Gardening Academy Organic Vegetable Gardening: My new premium online course. The course is designed to be a comprehensive guide to starting, growing, nurturing and harvesting your favorite vegetables, no matter what you love to eat, no matter where you live, no matter your level of gardening experience.
joegardener Online Gardening Academy Master Seed Starting: Everything you need to know to start your own plants from seed — indoors and out.
joegardener Online Gardening Academy Beginning Gardener Fundamentals: Essential principles to know to create a thriving garden.
joegardener Online Gardening Academy Growing Epic Tomatoes: Learn how to grow epic tomatoes with Joe Lamp’l and Craig LeHoullier.
joegardener Online Gardening Academy Master Pests, Diseases & Weeds: Learn the proactive steps to take to manage pests, diseases and weeds for a more successful garden with a lot less frustration. Just $47 for lifetime access!
joegardener Online Gardening Academy Perfect Soil Recipe Master Class: Learn how to create the perfect soil environment for thriving plants.
Stack / Whitney Entomology, Environment and Technology Col(LAB)oratory
“Ladybugs: The (Natural) Enemy of My Enemy Is My Friend? Enlisting Ladybugs into the War on Insect Pests” by Kaitlin Stack Whitney, Ph.D.
Kaitlin Stack Whitney, Ph.D. on Twitter: @kstackwhitney
High Country News: “Am I an invasive species? How COVID-19 and ‘murder hornets’ compelled a writer to rethink invasions” by Jenny Liou
Disclosure: As an Amazon Associate, I earn from qualifying purchases. I receive a commission every time you purchase a product through an Amazon affiliate link. Some product links in this guide are affiliate links. However, none of the prices of these resources have been increased to compensate us, and compensation is not an influencing factor on their inclusion here. The selection of all items featured in this post and podcast was based solely on merit and in no way influenced by any affiliate or financial incentive, or contractual relationship. At the time of this writing, Joe Lamp’l has professional relationships with the following companies who may have products included in this post and podcast: Milorganite, Soil3, Territorial Seed Company, Cool Springs Press / Quarto Group and Dramm. These companies are either Brand Partners of joegardener.com and/or advertise on our website. However, we receive no additional compensation from the sales or promotion of their product through this guide. The inclusion of any products mentioned within this post is entirely independent and exclusive of any relationship.
