- Coming up on Sci NC, the leech with a strange love for alligators, the PhD students learning how our coast fights back against erosion, and why no two bugs take flight quite the same way.

Next.

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- Sci NC is supported by a generous bequest gift from Dan Carrigan and the Gaia Earth Balance Endowment through the Gaston Community Foundation.

(gentle music) ♪ - Hi again, welcome to Sci NC.

I'm Laura Smith.

Leeches don't typically grab headlines, but there's one that's a real sucker for alligators and it's raising eyebrows inside the North Carolina Museum of Natural Sciences.

Some even make their home right on a gator's tongue of all places.

Isn't that wild?

Here's Sci NC's Evan Howell.

- [Evan] This is the story about the leech and the alligator.

We all know about alligators and how it's best to keep our distance, but then again... - Who wouldn't be excited about sticking their hand in the mouth of an alligator?

- [Evan] Okay, maybe a few of us wouldn't be that excited.

Then there's the leech, known for their blood-sucking preferences in the nearby creek when we were kids.

(growling creature) (scream) Leeches don't get much good press and they're not great at public relations.

- When you say leech, I think the knee-jerk reaction is generally one of revulsion and disgust.

- [Evan] What do these two beings have in common?

In a state where leeches quietly support the ecosystem, it's remarkable that one species out of hundreds worldwide has chosen alligators as its preferred host.

- Kind of giving a bad rap to an entire group of organisms that's not necessarily well-deserved.

- [Evan] But about half of the world's leeches feed on blood.

Only about 10 to 15 of those go for human blood.

Bronwyn Williams is an expert.

- We probably have over 30 species known of leech, known from North Carolina.

Only two of which are known to feed on humans.

This is still a small-ish one.

They get bigger.

- [Evan] Williams has spent more than 20 years studying crayfish and the small organisms that live on them.

Tiny invertebrates that led her into the wider world of leeches.

A group found in freshwater habitats almost everywhere on Earth.

- Hey, that's your name on this.

- It is.

I collected that.

- Awesome.

- I think one of the favorite things about my job is that I can just walk across the hall, come back into the collection, pick up a jar, look at it and go, "What is this?"

- [Evan] Literally next door to Williams' workspace at the Research Extension of the Museum of Natural Resources is one of the largest research collections in the Southeast.

A long-running record of the region's reptiles, amphibians, and freshwater invertebrates.

And leeches, of course.

- All right.

- Oh my.

- There you go.

So this narrow end that's up in the air, questing around, is actually the head end.

So it's attached to your, or semi-attached to your hand by its butt sucker.

- Its butt sucker?

- Its butt sucker.

- Oh, that's nice.

I'm glad it's secure.

- It is very secure.

- [Evan] Williams lives for this kind of stuff.

And so does Miriam Boucher, a South Carolina researcher who studies what alligators eat.

When Boucher started finding leeches clustered on the tongues of local alligators, including some in the southern part of our state, she reached out to Williams for help figuring out what they were.

- She followed that initial message up with, "Well, we're finding large leeches on the outside of the alligators, so largely on the back or kind of between the toes.

And we're finding all these little leeches in the mouths that seem to be clustering on the tongue of the alligators."

And so she sent me these specimens to look at, and they appeared to be two different species, which was kind of wild.

So we've got kind of these two species that thought one was thinking that the back of the alligator was a great place to call home, and one thought that the mouth was a really nice, safe place to call home, as it were.

And that's a little mind-blowing.

- [Evan] But why is that mind-blowing?

Well, part of it is that because leeches all have their preferences of hosts, amphibians, birds, mammals, and it looks like finding a leech on an alligator is weird.

- Then we were actually able to use genetic methods to show that these were actually the same species.

So those little leeches that were found on the tongue of alligators are actually the little juvenile leeches of the big ones that we find on the back of the alligator.

More of a heart-shape, kind of flared.

- [Evan] Back in the lab, William showed us how they look at and distinguish one leech from another.

- That's actually its blood meal.

So that's alligator blood still in the leech.

- Blood meal?

- Blood meal.

- That's a curious word.

- As you scan around, see, they all look the same.

The pattern is almost they have a single row, if you want to look in the microscope here.

- Yeah, please, thanks.

- Sort of a single row that looks like a checkerboard down the middle of the back, and then they've got several lines of tubercles or these bumps on the back.

- It's like a mosaic on the back.

- It is, yes.

- [Evan] North Carolina marks the northern edge of the American alligator's range, a boundary where animals and the species that live on them can behave differently than they do farther south.

- It was a 700-pound alligator, so there were a lot of-- - [Evan] Dr.

Stuart is an expert in this area.

- The idea of there being a leech on an aquatic reptile or a semi-aquatic reptile is not a far-fetched idea, but it's just amazing to me that our largest species of reptile, such a conspicuous parasite, would go undetected for so long.

- [Evan] For Williams, every specimen is a clue, part of a larger story about how life adapts, survives, and sometimes surprises even the people who study it.

- This is a jar of white shrimp.

This is the oldest specimens in the invertebrate collection here.

These were collected in Charleston, South Carolina in 1855.

- 1855?

They're in pretty good shape for being that old.

Basically, a species is somewhat equal parts philosophy and biology, right?

It's a human construct, but that is the critical foundation for conservation and management.

So there is a lot that's riding on what we call species.

- Now that's one brave leech, but then again, rather him than me, right?

All right, I think you agree with me there.

Let's go ahead and get to something a little friendlier.

Along our coast, one idea is doing double duty, protecting homes from erosion and helping marine life thrive.

UNC studies these living shorelines, tracking everything from seagrass to stingrays to see how nature's defenses help us all.

Take a look.

♪ - I feel like at some point all little kids want to be a marine biologist and go study dolphins and whales or sea turtles.

And I guess I just never really grew out of that.

My name is Alexis Longmire.

I'm a PhD student in ecology at UNC's Institute of Marine Sciences.

I've got two projects going on right now looking at the landscape impacts of large scale living shorelines.

They protect a shoreline from erosion, but also rebuild lost habitat.

The ones that I study specifically, there are these sill-like structures that hopefully should accrue oysters over time, build back a natural reef, and then oftentimes we plant marsh grass behind it.

The first project is looking at whether living shorelines potentially negatively impact nearby seagrass beds.

Here in North Carolina, we have like the highest acreage of seagrass along the East Coast, but we're losing it at a very high rate.

In some areas, higher than the global seagrass loss rate.

And so for that project, I just go out and I just survey seagrass around living shorelines and see if over time, they're moving away from the living shoreline, coming back, or losing density and things like that.

My other project is looking at whether these large scale living shorelines affect larger animal movement.

And so I'm focusing in on predatory fishes, red drum, speckled sea trout, southern flounder, sting rays, and majority of those are really, really critical to our commercial and recreational fisheries here in North Carolina.

So typically what we will do is we'll go out on the water, we'll take the boat over to one of our sites, and we will set up this really, really long bordered footnet off the side of the boat to enclose an area of a living shoreline.

And within that, we can release a few tagged predators at a time with an array of receivers, and let them interact with that living shoreline over the course of a few tides and see if they're able to get back there or not.

In my experience, the sting rays don't seem to have any problems going behind the living shoreline, but they're also really flat.

So they're probably one of the few species that can swim over the top of the living shoreline.

So if you're a really big red drum, for example, you're not getting over the top.

In North Carolina, the permitting requires that for every 100 feet of structure, there's a 10 foot gap.

So that's the point is to entrap animals in the area and see whether they can utilize those gaps across the tide to forage and get food.

There is absolutely no way I could do all this by myself or even with just one other person.

I rely very heavily on my lab mates, my friends, colleagues here at the Institute of Marine Sciences.

But that's just sort of the community that IMS is.

It's very collaborative, and I think that really enriches the sort of research that we can do here and accomplish here.

- I tell you what, that is one cool classroom, isn't it?

Hey, medical breakthroughs are coming faster than ever, and a lot of that speed comes from machines.

From vaccines to medicines, automation is doing the work on a bigger, faster scale than people ever could.

But as Sci NC's Evan Howell finds out, there's still one thing the machines can't replace, a human touch.

- [Evan] It takes more than a decade and tens of millions of dollars to get medicine to the people who need it.

And a lot of that testing is done by hand.

- So this is a very common tool that scientists regularly use.

- [Evan] Which makes creating and testing medicines take longer and cost even more.

Today, automation has transformed how we do cancer screening, distribute vaccines, and conduct mRNA research.

Platforms like this can multiply an experiment or build parts of a vaccine hundreds of thousands of times in a single sweep.

So how do you start handling that?

Cue a robot.

- That's why labs have gravitated more to these automated liquid handling robotic workstations.

And liquid flows out of the tip.

- [Evan] But doing it manually is still a practice in labs not tasked with handling huge sample amounts.

But as they say, use the correct tool for the job.

- And in terms of volume, we're talking in the one milliliter range, generally speaking.

So with this hand-held pipette, what you can do is you just place the pipette tip into the liquid.

You displace the plunger.

Liquid flows into the tip.

And there you have aspirated your liquid inside the tip.

From there you can then transfer it to some other labware to then dispense it.

And liquid flows out of the tip into the well.

- But it could always be done better, right?

- Right.

So while this shows just a one-to-one transfer, what if you have a lot of different liquids that you need to transfer?

You're processing many samples.

- [Evan] In the 1950s, as Jonas Salk's polio vaccine was rolled out, production was slow and risky.

Technicians even used mouth pipetting, a method that put them at risk of infection, obviously.

Each drop was handled by hand.

By 2020, the COVID pandemic made clear that manual methods could not keep up.

Automation became essential to produce vaccines at the scale that was needed.

- COVID demonstrated the necessity of such automation because there was such a demand for high volume of samples to be turned around in a quick, reliable, and safe way.

- [Evan] And vaccine work moved from single test tubes to flat plates, holding many samples.

It's flat, though.

I mean, how do you put a pipette in this thing?

- It's very thin, and there's a very thin, similar, it's analogous to that of the hand-held pipette because there is a small piston inside that also moves up to displace the air to actually pick up the liquid.

What we can do on our robotic workstations is that we can have many of these pipettes to process hundreds and thousands of samples.

- [Evan] So we watched how this all fit together and how the robot figures this out in a demonstration.

And it starts with getting the liquid out of these tiny tubes.

- That's a crazy black tip you got there.

- Well, it's black because during manufacturing, the tip is infused with graphite.

We have circuits built into our pipettes, which means as the tip makes contact with a conductive liquid, it will ground that circuit, and now the robot knows exactly where the liquid is.

- [Evan] The robot has to first get things into position.

It first moves what are called microtiter plates, which are plates with 96 multiple small wells that are used as miniature test tubes like we saw in Dr.

Salk's polio lab.

- Now that it's been presented into the workspace of the pipetter, we have what's called an IPG, an internal plate gripper channel, which is gripping this microtiter plate and is going to move and transport it to the left side of the deck to be staged for downstream processing.

- [Evan] What that means is that this plate is being put to the side and will wait for samples to be put into it in a moment.

- The gripper, using a strain gauge, has detected force and knows that it's holding an object.

- [Evan] The robot then takes what is called a random access plate, holding sample tubes in rows with these green caps.

This plate has barcodes, which are scanned by cameras to match the sample cups to be shipped out.

[machine sounds] The tube caps are removed row by row with 12 separate motors, and those are put to the side as well.

Now that the samples have been processed in our demonstration, those tips are thrown away.

At that point, the other arm will take the microtiter plate with the 96 little cups for science and put them into position.

- So our 96 multiprobe head is now aspirating another reagent out of a trough.

We'll dispense this into our sample tubes that have been decapped.

- [Evan] The machine pulls reagent from a trough and adds it into the sample tubes.

It then moves those samples into plates where the more ingredient mixing happens.

It repeats the process, handling 96 samples at once and stamping the results onto multiple plates.

- Demonstrating the power of this type of liquid handling automation, we're preparing 596 plates, which is 480 samples, including decapping of tubes, processing of barcodes in a very rapid amount of time.

A human simply just can't do this and wouldn't want to.

- [Evan] Speed matters and so does safety.

Inside those trays are patient samples and other substances too dangerous to risk with human hands alone.

- Lab operators are handling biohazardous material.

This is often human samples that they're handling, or they're dealing with very volatile reagents and chemicals.

- [Evan] Here at North Carolina's Research Triangle Park, drug and research giants all depend on faster, more reliable solutions and so do their counterparts around the world.

- Accuracy and reliability and safety is important.

And so by adopting this type of automation and this type of technology, you can be assured that you have much more reliable results in the end.

♪ you have much more reliable results in the end.

♪ - Well, we just saw how technology is speeding science up, but now let's slow things way down.

It turns out every flying insect has its own unique way of getting off the ground.

At the North Carolina Museum of Natural Sciences, Adrian Smith uses the magic of slow motion to show us liftoff like we've never seen it.

Take a look.

- This is a monstrously big insect.

It's a female Dobson fly.

In its aquatic larval form, this insect is often called a helgermite.

But here, as an adult with its giant wings and long, flexible body, I think it's about as dragon-like in appearance as an insect can get.

Dobson flies belong to an order of insects called megaloptera, named that because of their huge wings.

In that order, the closest thing to them is what you see here, a fish fly.

Fish flies are in the same order in family as Dobson flies and are like them in a lot of ways.

Most of their lives are lived in the water as predatory larval insects.

Once they get to this stage, they're at the tail end of their life, living only a few weeks or so and feeding rarely, if even at all.

To get a sense of how similar these two insects can be, in this scene you're seeing a female Dobson fly on the left compared to a female fish fly on the right.

Slight anatomical differences like the size of their jaws and the shapes of their antennal segments make them distinguishable.

But, as you're seeing right now, the adult flight behavior between these two insects is a very close match.

The only other group of insects in the megalopteran order are these, alderflies.

Like the last two, the larval stage of alderflies are aquatic, so if you're lucky enough to see an adult like this, you're probably near the water source it grew up in.

Worldwide, there are only 100 species of alderfly, and with only a few hundred more species of Dobson flies and fish flies, that makes megaloptera one of the smallest orders of insects.

For this video, I put together a collection of insects and flight sequences I think are a little odd.

For all these clips, they either show something really interesting, or are insects I haven't seen captured in flight before.

Take, for instance, this one.

This is an owlfly.

Owlflies look kind of like damselflies or dragonflies, but they're neuropterans closely related to things like antlions and lacewing insects.

This one would only move in front of my camera if I brushed it into action with a little paintbrush.

That's because at rest, they spend their time hanging out on vegetation like this, probably trying to blend in as a twig or camouflage themselves while being more or less in plain sight.

Here's this one taking off after being brushed from that resting position.

Some things to notice here are the clubbed, butterfly-like antennae, which are a feature of all owlflies, the giant eyes, which are useful if you're chasing down other flying insects as prey, and their impressive tarsal claws at the end of each leg, probably really useful for grabbing and holding onto something that's trying to fly away.

The next insect is a common one, but one that you don't see flying around too often.

These are termites.

Termites fly at particular times in the year to congregate, mate, and disperse to start a new colony.

They come out in huge numbers and drop their wings after they fly, so sometimes you just see a bunch of shiny wings on the ground the morning after a flight, but no termites in sight.

Compared to their bodies, their wings are huge.

Termites are a derived form of a social roach, and their wings do resemble the front wings of many roach species.

But while roaches have a larger and folded hind wing, the termite's wings are flat and uncomplicated.

Okay, now for some interesting beetle behaviors.

This is a net-winged beetle.

It raises its protective front wings in preparation for a flight, then the legs come up as it pushes off the ground, but it forgets to fly.

This one never flaps its hind wings and just tumbles over onto the ground.

It's like all the steps before wing flapping happened, but then things just stop and flight never happens.

Besides being kind of funny, it is informative to see this happen, because you get to see how much the legs and jumping are tied to flight behavior.

This one gets some good momentum going by standing and doing a little hind leg powered jump, but the whole body only gets a couple millimeters off the ground.

From there, normally wing flapping would be happening fast enough to continue lifting the beetle up and off the ground.

For comparison, here's a different species of net-winged beetle doing a better job flying.

For this one, while it's using the legs to stand and hop, it's also flapping the wings and gets four flaps in before the hind legs are up off the ground.

You might have also noticed that this beetle has a long snout with finger-like projections sticking off of it.

Those are sticky masses of pollen called polynia that this beetle picked up from rooting around on milkweed.

Both this beetle and the other net-winged beetle were hanging out on a patch of milkweed in southeastern Arizona.

The next beetle with some interesting behavioral quirks is this one, a click beetle.

Now, click beetles, of course, are famous for their clicking behavior, which is when they use a spring system to quickly flex their thorax, which throws them off their backs and up into the air.

They're also pretty good at flying, too.

In fact, when I usually come across a click beetle, it's either flown to a light or is up off the ground hanging out on leaves or on the bark of a tree.

The best part about this particular one is this.

This pale spot on the thorax is a light-producing organ.

These click beetles are bioluminescent.

Here's what their spooky green glow looks like when they scurry around on the ground.

The light they produce is pretty bright, and they'll do it when they're disturbed like this one does when I gently grab a hold of it.

Click beetles are closely related to fireflies, and they use the same molecules and enzymes to produce their light, but the two groups likely evolve light production independent of each other.

Next is one of North America's most attractive beetles, a leaf beetle called the dogbane beetle.

It's called that because dogbane is a plant that both the adults and larvae specialize on.

It's a native plant that's toxic to vertebrates, but it's host to this beetle and several species of moths that have figured out how to use it as a food source.

These adult dogbane beetles are shockingly iridescent.

The whole body from the legs to the undersides of their abdomen have a metallic shimmering green, while the topsides of their forewings shine with reds and yellows.

The bright colors might serve as a warning signal to potential predators, advertising some of the toxic compounds and distastefulness these beetles pick up from their host plant.

Continuing on the theme of extraordinary insect colors, this is a green horsefly, and in the background of this shot is a tip of my index finger to give you some scale for how huge it is.

Horseflies like this consume plant pollen and nectar, but also females are blood feeders, requiring blood as a protein-rich food to aid in egg development.

When this one lifts off, watch closely to the body right behind the front wings, and you'll see the halter, which is the hind wing that has been modified into a flapping gyroscope.

A much more common version of green color in flies is the iridescent green you're seeing here on the fly on the left, which is similar to the dogbane beetle you saw just before this.

The more flat, pigmented green that the horsefly has is pretty unique among flies.

In fact, of the hundreds of horsefly species in the U.S., this is the only one that looks like this.

This is a stilt-legged fly.

Believe it or not, this fly is a wasp mimic.

But instead of being shaped like or having an overall body color scheme like a wasp, what it does to mimic them is mostly through behavior.

They hang out on leaves and stick their white-tipped front legs out in front of their bodies.

As they walk around, they rapidly vibrate their legs to mimic the constant sweeping motion that a wasp would be doing with their antennae.

In flight, they seem more fly-like than wasp-like to me, though it does look like they still hold their front legs forward.

Maybe they're trying to mimic wasp antennae when they fly, too.

These last two clips I wouldn't normally include in a video because these shots aren't quite good enough for me, but I had to put these here because they definitely fit the oddball theme of this video.

These are two aquatic insects.

On the left is a backswimmer, and on the right is a water boatman.

They can hardly stand or walk, but they do fly.

In fact, both of these flew to a light trap I had set up.

To get off the ground, they use one powerful swing of their paddle-like hind legs to launch themselves into the air.

That's the same motion they'd be normally using to swim, so it's interesting to see them use it here to start their flights, too.

Okay, that's it for now.

Thanks for watching.

- Aren't they all just so fly?

Get it?

All right, I'm cheesy.

All right, that's it for Sci NC this week.

If you want more Sci NC, be sure to follow us online or on Instagram.

We're also on YouTube and our website, pbsnc.org.

I'm Laura Smith.

Have a good one.

(gentle music) ♪ ♪ ♪ ♪ - Sci NC is supported by a generous bequest gift from Dan Carrigan and the Gaia Earth Balance Endowment through the Gaston Community Foundation.

- Quality public television is made possible through the financial contributions of viewers like you, who invite you to join them in supporting PBS NC.