Insectarium

Have you ever seen a killer flower?

A deadly dead leaf?

A homicidal stick?

The mantis is a master of disguise.

Unlike many animals that use camouflage to hide from predators, mantises are serious hunters who also deploy it to better ambush their prey.

With a flick of their forelegs, these carnivores can go from disguised to deadly, even going after much larger prey like birds, mammals, and other vertebrates.

But they didn't always have such spectacularly cryptic looks.

If you were asked to quickly draw a bug, you'd probably end up with something like a mantis ancestor: a generally oval-shaped thing with no fancy forelimbs or transfixing stare.

Basically a sack with legs.

But from that basic blob, mantises have evolved into eye-popping predators.

And all over the world, strikingly similar adaptations have appeared in independent lineages.

Now, researchers are using new tools to get a closer look at just what makes these insects such impressive hunters.

The answers may be surprising.

So, mantises they're all hunters, right?

Yeah.

So that's one thing that's kind of universal for mantises is that they're predators.

That's their lifestyle.

That's their strategy.

They bought into that, hundy.

Their body shapes can be wildly different, but there are some commonalities that make them good hunters.

They have stereo vision, incredibly rare in the invertebrate world, and specialized head movements that sharpen their depth perception.

It feels like nature probably has a reason for that.

Why is that advantageous for mantises?

So mantises are really visual predators, basically need to be able to just kind of scan their surroundings.

And they need to have flexibility when they're aiming at prey.

Importantly, they also have these raptorial forelegs, spiky appendages that let them strike and hold prey.

Mantises tend to be, a lot of them are kind of sit-and-wait predators.

So they will sit kind of perched with their forelegs ready, and then when a prey item comes by, they shoot, part of their raptorial forelegs forward.

It's kind of remarkable.

the force that they can do with this, with this structure, right?

That's an awkward motion.

Yeah, well, I mean- - For a human, for a human.

Yeah.

I was gonna say I'm- I mean, I haven't evolved to do this.

If I had spent 135 million years evolving to do it, maybe Id be better at it.

But the prey item gets caught, and they bring the forelegs up to the mandibles, to the mouthparts, And they eat it like a corn.

Little corn on the cob.

Theyre like this, which is very cool.

One person very familiar with this motion is graduate student Lohit Garikipati.

I've probably watched thousands of thousands of strikes of them eating over and over, and it's just so exciting to watch them.

And it's pretty incredible because they're- I mean, they're really using just two legs without any venom or any other assistance to really hold down a prey item.

And in some cases, stuff that's bigger than even they are.

And my research is sort of dealing with how they're accomplishing that.

So looking at how different species that maybe evolved a similar cryptic strategy, like two stick-mimicking species, whether or not they're hunting similarly, compared to, say, a flower-mimicking species.

Here's the thing about mantises.

While they developed incredible forms of camouflage over millions of years and many different locations, their evolution has converged on a few particularly successful types.

You tend to have species that are bark mimics, or leaf mimics, or dead leaf mimics, Flower mimics.

or stick mimics or grass mimics.

over and over and over.

mantises have converged to look like the same kinds of things.

This species, Phyllocrania paradoxa, is from Africa.

and this one, Deroplatys truncata, is from halfway around the world in southeast Asia.

These two are in different genera.

Believe it or not, this species, Phyllocrania paradoxa, is more closely related to orchid mantises than it is to this Deroplatys truncata dead leaf mantis.

And this Deroplatys is actually more closely related to this stick-mimicking species.

So these two mantises come from totally different parts of the world and have totally different evolutionary histories, but they're like doppelgngers of disguise.

Both have these wide thoraxes and they have that brown mottled coloration and leg lobes.

So we could probably agree that they're dead-leaf-mimicking species.

We call that an ecomorph: a morphology or body plan that's shared by individuals in the same ecological niche space.

It doesn't matter if they're close relatives or not.

And that can be a headache for scientists trying to untangle the mantis family tree.

Historically, you know, this caused a lot of confusion for researchers because before the advent of widely used genomic data, people understandably would think that if its mimicking a dead leaf, they must be related.

Which in some sense it makes sense, because these are complex structures that take a while to evolve.

But in light of, recent studies that are showing that they're actually distantly related, it becomes that much more interesting.

Because now the question is, okay, we have two organisms that evolved in different parts of the world from different lineages, but they repeatedly have developed these very similar cryptic structures.

And I think that can tell us a lot about how they're interacting with their ecosystem, how prey is trying to avoid them, and how this cryptic strategy is actually able to help them survive.

Studying mantises is nothing new for Lohit.

I've been interested in praying mantises for a very long time.

I've been, raising them- - Like since childhood?

Yeah.

Since childhood.

So, sort of over the course of keeping different species over multiple years, I got to sort of recognize that there are differences in how they're going about approaching the prey or when they want to actually strike at the prey based on the preys size or movement.

That sort of got me thinking from a research perspective, well, does that mean they're actually using those raptorial forelegs differently to get that prey?

Observing animals in life often provokes new questions for researchers.

There- this position of her body is kind of fascinating.

An ethogram is the study of behavior.

Like the traditional ethology or ethograms that were done was just like a human being, a pair of eyeballs, a pencil and a paper.

Right?

And you kind of would watch an organism for 15 minutes or for 30 minutes, kind of document the behaviors that you observed.

But now we have the ability to have cameras positioned in all different locations in the lab to record things like force and strike distance for praying mantis forelegs.

Lohit and his advisor, Dr. Christopher Oufiero, use a high-speed infrared camera set-up to get a better look at how mantises are making their strikes.

They'll position a mantis on this platform and tempt her with a nice juicy cockroach.

So why do you want her to be upside down?

So normally, mantises are hunting upside down in the wild.

They're usually perching underneath something, whether it's a stick or a leaf.

And so we just figure, were trying to give them as natural of a setup as we can in the lab.

So she's thinking about it.

You can see she's, like, inching in and grabbed.

We're filming at a thousand frames per second to capture that strike because it's so fast, almost as fast as one third of the blink of an eye in some cases, or even faster for some of the species.

So we really need that high frame rate to capture the motion.

Mantis strikes are captured by two cameras, one on the top and one on the side, to give a three dimensional view.

Historically the research on mantises was done using 2D views.

But that top view really allowed us to notice a lot of variation in the strike, as they're throwing those raptorial forelegs out.

Which was all missed before.

After doing this hundreds, if not thousands of times, Lohits determined that while mantises all use their raptorial forelegs for hunting, it turns out there are definitely some nuances in style.

The Euchomenella, theyll really just watch the prey for a good while and then they'll go for a strike.

But some species just fire off a couple really fast.

Wayne Gretzky said you miss a hundred percent of the shots you dont take.

That's what he said.

Lohits ongoing research is trying to understand whether there may be similarities between ecomorphs that could tell us more about how environments shape the animals living in them.

Is it that similar niche spaces always inspire similar hunting strategies, or could you have multiple hunting strategies within a particular ecomorph?

What you need to do is actually observe.

Research collections are incredibly important for scientists, but even when we combine that information with genomic work, there's still a big missing piece of the biological puzzle.

If you're just, you know, taking legs off to grind them up for DNA, you're not going to discover depth perception.

You're not going to discover that some species have a weird cyclopean ear that may help them avoid bats, or that some species practice maternal care.

To do that, you really need to be carefully looking at their anatomy and you have to do behavioral work.

There's a lot of people who, I think, are using really creative approaches to study behavior right now.

And it's kind of an exciting time to be an ethologist.

Mantises are some of the most unearthly looking animals on Earth, but they're uniquely adapted to life on this planet.

New technology is helping us analyze their amazing behaviors in the lab, but there are plenty of things to discover even without access to fancy tools.

I think a lot of the challenge with mantises is because theyre very good at hiding, theres definitely more diversity out there.

If people start exploring their own backyards more, who know what theyll end up finding?

Definitely keep an eye out.

So, just to address the elephant in the room: yes, some, but not all, mantises engage in sexual cannibalism.

Female mantises get a bad rep.

Right.

People are always talking about cannibalism because they often tend to need a meal, when they're- during the reproductive stage.

But that's because this has to come out of her.

This is a mantis egg case called an ootheca.

And it's really energetically expensive to make this structure.

It can weigh as much as 30 to 50% of a mantis body.

So their strategy is to eat the closest meal that they can get, which is their mate.

Like, shes making life.

Okay?

Let her eat as many things as she can.

For other species, it might be a different story.

While courtship displays haven't been well documented in scientific literature, the males of some flamboyant species have been seen performing something like mating dances, with movements from flaring their wings and flashing their forelegs to display bright colors, to flaunting their abdomens.