Ladybugs Have a Killer Secret

[GENTLE, LULLABY TYPE MUSIC]

[Close-up of ladybug crawling over plants]

JESSICA WARE (Curator, Division of Invertebrate Zoology): How loveable are ladybugs? Look at those spots! Look at that lil round pop of color! 

[A few dozen ladybugs cluster together on leaves.]

WARE: A group of ladybugs is even called a “loveliness.” 

[Close-ups of bright, round ladybugs on flowers and nestled beneath leaf litter.]

WARE: They star in nursery rhymes and many of them—like a lot of us would love to do—find winter hideaways where they just sleep through cold weather. 

[LIGHT, CARTOONISH SNORING SOUND]

[Close-ups of ladybugs on plants.]

WARE: Awwwwww. But it turns out, ladybugs have some… unexpected qualities. They’re a little more sinister than you might think…. 

[MUSIC SHIFTS TO PLUCKED STRINGS WITH SLIGHTLY MENACING OVERTONES]

[Extreme close-ups of ladybugs devouring aphids.]

WARE: They can be beautiful killers—an adult may take out more than 5,000 aphids in its lifetime—usually a little over a year. 

[Ladybug larva eats another ladybug.]

WARE: And they don’t stop there: if their normal prey runs low, ladybugs can turn on other insect predators, or even on one another… 

[Ant pushes ladybug to the side of a flower.]

WARE: And to top it off, when ladybugs are provoked, they’ve got quite the defensive strategy—something called “reflex bleeding.” 

[Extreme close-up shows viscous, mucous-type fluid seeping from a ladybug’s joints.]

WARE: They secrete these drops of off-putting toxic blood from their leg joints. Wow. 

[Ladybugs nestle in the curl of a leaf and crawl on flower petals.]

WARE: But don’t change your mind about loving ladybugs! Some of those noxious chemical compounds just might make ladybugs even more beloved by humans…

[Title animation: INSECTARIUM]

[On-screen text: American Museum of Natural History]

[Jessica opens a row of cabinets in the Museum’s Entomology research collection.]

[On-screen text: Entomology Department | American Museum of Natural History]

DIRECTOR [off-camera]: So, Jessica, I've heard some people call them ladybugs. Some people call them lady beetles. Some people call them lady birds. Are those all the same thing? 

[On-screen text: Jessica Ware, Ph.D. | Curator, American Museum of Natural History]

WARE: Yeah. You can pretty much use those names interchangeably. They’re all beetles, so they’re all Coleoptera. 

[On-screen text: Coleoptera | beetles]

WARE: And we tend to want to kind of move away from calling them ladybugs because they're not bugs. Peer pressure—try and call them lady bird beetles. 

DIRECTOR [off-camera]: Tell your friends.

WARE: Tell everyone you know: they’re lady bird beetles now.

[Close-ups of ladybugs that are red with black spots.]

WARE: They’re all beetles in the family Coccinellidae. That name comes from the Latin word for scarlet, but they’re all kinds of different colors. 

[Ware pulls out a drawer of specimens from the collection cabinet. An extreme close-up of the specimens shows varying colors and patterns from all red, to yellow with black spots, to a bluish-gray color.]

WARE: This drawer has just in this one genus here, a variety of color and shape.

DIRECTOR [off-camera]: So, all ladybugs aren’t red and black? 

WARE: I think the ones that often many of us are most familiar with are ones that are kind of red and black in color.

[Still images of ladybugs with diverse colors and patterns appear in rapid succession—red, yellow, pink, iridescent bluish-purple, white with black spots, etc.]

WARE: But since there’s like 6,000 different species of ladybugs worldwide, they come in lots of different colors and patterns. 

[Ware in the Entomology collection.]

DIRECTOR [off-camera]: I feel like people have a really soft spot for ladybugs, even if they don't like insects. Why do you think that is?

WARE: Well, part of it, I think, is just that they're very beautiful. 

[A red ladybug with orange spots sips from a drop of water on a flower petal.]

WARE: We tend to like beautiful things, and we tend to kind of give special attention to things that we think hold beauty. 

[Ware speaks to camera in the research collection.]

WARE: Part of it might just be that people tend to think of them as kind of good luck or as good actors, beneficial insects. 

[Ladybugs crawl around in soil at the base of food crops.]

WARE: For over a hundred years, farmers have been using ladybird beetles as kind of green pest management because they like to eat aphids. 

[Extreme close-ups of aphids on plant stalks. Some have wings and some are more like green or black blobs sucking sap from the stem.]

WARE: Aphids are these tiny, tiny insects that feed on plant sap. They can sometimes be problematic for farmers and gardeners not only because they chow down on crops and flowers, but because they can transmit viruses from one plant to another. So, we don’t love them. 

[Ladybug adults and larvae gorge themselves on juicy aphids.]

WARE: But for ladybugs, these are just juicy green insect cupcakes. Some larvae  can eat their own weight in aphids in one day. So they’re kind of like our agricultural allies.  

[Exterior of a large brick building on the Penn State campus. A sign reads Agricultural Sciences & Industries Building. Ware and Sara Hermann walk and talk in a corridor.] 

WARE: Dr. Sara Hermann runs a lab at Penn State’s College of Agricultural Sciences where she and her team study insect predators—like ladybugs. Tell us where we are. What are we looking at here?

[Camera moves around Dr. Hermann’s lab. About 20 mesh enclosures line several shelves. Each contains grasses crawling with ladybugs.]

[On-screen text: Hermann Lab | The Pennsylvania State University]

[On-screen text: Sara Hermann, Ph.D. | Assistant Professor, Pennsylvania State University]

SARA HERMANN (Assistant Professor of Arthropod Ecology and Trophic Interactions, Pennsylvania State University]: We are in my lab here at Penn State University, where I study a lot of different things, one of which is ladybugs. And so this is our wall of ladybugs, here. We have two different species and multiple different life stages of the ladybugs that we work with in the lab.

[Hermann adjusts a lab set-up consisting of tubes and glassware. Ladybugs crawl inside some of the glass containers.]

WARE: I am fascinated by Sara’s work because she studies a chemical concoction from ladybugs that you could think of like a perfume of fear. 

[Hermann and Ware talk in the lab space.]

HERMANN: I'm really excited about thinking about predator-prey interactions. And when we think about predator-prey interactions, we're usually just thinking about predation—so, how much of something is getting eaten by a predator? But my lab focuses on the other side of the coin, so the non-consumptive effect— 

[Ladybug perches on a leaf near a stem covered in aphids.]

HERMANN: …the other ways that predators might influence the prey organisms without actually eating them at all. And the way that they can do this is just by being present in the vicinity of a prey organism. The prey—here, aphids—can detect that through odor cues or the smell of the ladybug. 

[Extreme close-ups of many aphids clustered on a plant stem and crawling on leaves.]

HERMANN: And they use that information to change their behaviors in a way that reduces their risk of being eaten. So we're trying to understand how aphids respond to these ladybug smells and if they change in ways that are beneficial for plants that we want to eat as humans.

[Hermann works at a station in her lab.]

WARE: Sara’s trying to figure out if we can improve crop protection by harnessing the power of non-consumptive effects like that natural bouquet of ladybug chemicals. 

[Camera pans across Hermann’s lab set-up. Some glass jars containing ladybugs are connected to flexible tubing and other containers that collect odors from the insects.]

WARE: So, the smell seems to scare off, or repulse, aphids. So, what do ladybugs smell like? 

[SNIFFING]

[Ware sniffs a ladybug crawling on her hand.]

HERMANN: The adults definitely have a very specific odor. They say it smells like chips or French fries or bell peppers or lots of different things have actually been mentioned as their odor.

[Ware and Hermann speak in the lab.]

WARE: That's funny. A new- a new Yankee candle scent. I’m just sensing it, right?

[The video freezes and an animated sparkling transition reveals a red scented candle jar with a picture of a ladybug and a label reading “Ladybugs”] 

[Ladybugs crawl inside the lab glassware.]

HERMANN: And so what we have been doing is we have collected all of the odors that these ladybugs produce. 

[Hermann drops liquid from a pipette into small glass containers.]

HERMANN: And we can test them individually or as a blend, sort of like a perfume of ladybug. And then we can take that to the field, in theory, put that out there and see if we can disrupt these aphids in ways that’s beneficial for crop production.

[Hermann and Ware speak in the lab.]

WARE: So, it’s the smell of fear. The smell of fear! Why don't we just put a bunch of ladybugs out? I mean, putting out the perfume, what's the advantage of doing that versus just putting out ladybugs?

HERMANN: Yeah, so we do release ladybugs, sometimes. 

[Dozens of ladybugs crawl from a mesh bag onto vegetable seedlings in a raised bed.]

HERMANN: We call that augmentative biocontrol. The advantage of this strategy would be that we are sort of maximizing the entire predation effect. 

[Hermann and Ware speak in the lab.]

HERMANN: So the ladybugs are going to be around and that's great. But if they're not around in huge numbers, at least we're getting these behavioral changes in the aphid prey that are beneficial to the crop. 

[Ladybugs crawl on a stick and a blade of grass. Close-up of one spreading its wings and taking off.] 

WARE: After all, we might have a hard time getting ladybugs to stay put. They’ve got wings and can fly away. 

[Ladybug crawls on a crop leaf.]

WARE: So, it can be tricky and expensive for farmers and gardeners to manage their release. And, when new ladybug species are introduced for pest control, sometimes they outcompete the ladybugs and other predators that are already there.

[Close-up of an oval-shaped ladybug that’s a pink-ish red with black spots.]

[On-screen text: Coleomegilla maculata | pink spotted lady beetle]

HERMANN: So I have two species here of interest, one of which is a native lady beetle, which is interesting because it is from this area. 

[Close-up of a rounder lady bug, red with black spots and a white section near its head.]

[On-screen text: Harmonia axyridis | harlequin lady beetle]

HERMANN: And the other species that we're studying is one that was introduced in the early 1900s, Harmonia axyridis. Once it was introduced to the United States, there was some concern that it would outcompete native species. 

[Ladybugs crawl in lab glassware. Hermann works with pipettes and small jars on her lab bench]

WARE: So, spritzing plants with ladybug scent could potentially avoid impacting local ladybug species, while producing positive outcomes in the field. 

[Dozens of ladybugs cluster on a branch.]

HERMANN: What we've studied so far is that we’re seeing fewer aphids coming into a field where the ladybug smell is. 

[Hermann and Ware speak in the lab.]

HERMANN: We're also finding that once they're on a plant and exposed to these smells, they're having fewer offspring and their overall population abundance is reduced.

[Scenes of cultivated settings—a wheat field, tulips, an arboretum, strawberries, etc.]

WARE: From fields of crops to my Nana’s tulips to arboretums like this one at Penn State, Sara’s work could benefit all kinds of growers. The goal is to increase crop yield, increase food security, and decrease insecticide use.

[Ware and Hermann talk in a wooden pavilion that looks out over a pond and an arboretum setting.]

[On-screen text: The Arboretum at Penn State] 

WARE: So I remember vividly, ladybugs as a kid. Is that how you got started? You just, like, loved them as a child? Like this is it. This is my destiny. I’m going to study everything about them. The aphids that they eat, the smells that they make.

HERMANN: No, Absolutely not. As a kid, I really was not a big fan of insects…

WARE: Oh, interesting.

HERMANN: So, I definitely never saw myself going into a career path where I was studying them specifically.

WARE: What did you think you wanted to do?

HERMANN: I wanted to be a singer, a musician. But what got me into entomology was a summer job as a research assistant. 

[Two white butterflies flutter around a field. A bumble bee crawls on flowers]

HERMANN: I fell in love with the idea of insect behavior, and I fell in love with the idea of sustainable agriculture. I realized that so much research informs policy and can make huge strides in change. 

[Camera tracks along rows of collard greens. Hermann consults with students in her lab. Tomato plants are covered in bell jars. A fluid bubbles in a beaker.]

HERMANN: And so I decided that I would continue down the path of research, hopefully to try to do some of that work that informs policy that could lead to sustainable agricultural solutions.

[Ware and Hermann speak in the arboretum.]

WARE: As an aside, I would say The Smell of Fear would be a very cool band name if you decided to stay in the music realm. I just want to give a plug for that.

[Hermann and one of her students tend to the ladybug colony in the lab.]

WARE: Sara’s research lets us ask big, fascinating questions about how organisms relate to one another and to their environment. 

[Close-up of aphids and ladybug larva crawling on collard green leaf.]

WARE: Non-consumptive effects—like the effects on aphids from that ladybug smell of fear—haven’t really been studied a lot in the insect world. 

[Hermann and Ware speak at the arboretum.]

HERMANN: It's hard to study because you're looking for something that you're expecting not to be there. So how do you measure something that's not showing up? 

WARE: Right. So, if it's so hard to study non-consumptive effects, why do you still do it? Like, why is it important to know about them?

[Ladybug eats aphids.]

HERMANN: Predator-prey interactions are one of the most important subjects in thinking about ecology, generally. They drive so much evolution. 

[Hermann and Ware speak at the arboretum.]

HERMANN: And if we ignore non-consumptive effects, we’re effectively taking away a huge portion of the possibility that a predator could have an impact on its prey. 

[Close-ups of different species of ladybugs crawling on grasses and flowers.]

HERMANN: Ignoring that means that our predictive power is just not very great, right? So if we want to think about populations over space and time and we're only thinking about consumption, we're leaving out a huge piece of the puzzle. 

[Hermann and Ware speak at the arboretum.]

HERMANN: There's going to be lots of different aspects of ecological interactions that we have to consider moving forward as the climate changes the way it has been. 

[Drone footage of a smoking, dry field. A person in a protective suit sprays pesticide on apple trees.]

HERMANN: Including chemistry and how chemicals allow for interactions among species.

[Ware and Hermann speak at the arboretum.]

WARE: It’s so interesting. I always thought about, you know, what are the impacts of climate changes on the organism. And we want to conserve the organism, we want to conserve species, but in a way, we want to conserve these unique chemistries, right? We want to conserve these unique molecules that evolved over I assume millions of years, as part of this co-evolutionary process.

HERMANN: Studying something that isn't well studied is both exciting and scary. 

[Hermann and Ware examine ladybugs in the lab. A ladybug larva crawls on Ware’s hand.]

HERMANN: It's exciting because you always have the opportunity to tell somebody something they had no idea existed. It also provides a lot of opportunities to make discoveries. So that part of it is exciting, as well.

[Credits roll.]

[Close-up of bright red and black ladybug on flower.]

WARE: Ladybugs have many different common names. 

[Ware speaks to camera in the entomology collections.]

WARE: In the UK, people often call them ladybirds. And in 17th century England, they were called lady cows. 

[A black and white spotted cow looks at camera.]

WARE: It’s gotta be the spots, right? 

[Close-up of a bright red ladybug on a green stalk of grass.]

WARE: In Spanish, a ladybug is mariquita…

[Different paintings of the Virgin Mary. In each she wears a red dress or cloak, or has a red aura around her.]

WARE: …a reference to the Virgin Mary, who’s associated with ladybugs in many languages, maybe because of the scarlet color she wears in some Medieval and Renaissance paintings. 

[In archival footage, a Korean shaman wears a red hat and a round red coat that balloons out as the shaman moves around.]

WARE: In Korean, the word for ladybug translates to “shaman beetle” because their red tint is similar to a shaman’s brightly colored robes. 

[Close up of a ladybug crawling on a leaf.]

WARE: Do you know of other common names for ladybugs? Drop them in the comments below!