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Diana Six teaches Hank about the Mountain Pine Beetle and all its glory, including taste! Then Jessi from Animal Wonders introduces Hank to a couple cuties he is not too sure about.

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HANK: Hello and welcome to another SciShow Talk Show, the SciShow episode where we talk about stuff with cool people. Now you may hear that the work out studio downstairs is having a bit of a dance party...just try to ignore it.

Today we have with us Diana Six of the University of Montana, a professor of Forest Entomology. So you study forest bugs.


HANK: That's - I guessed right.


HANK: I also have some special guests here [holds up petri dish] this, in this petri dish we have five dead pine bark beetles.

DIANA: Right, mountain pine beetles.

HANK: Mountain pine beetles. How many...pine beetles are there? I mean bark, what - OK t-t- what

DIANA: [laughs]

HANK: Tell-tell-tell me more.

[Both laughing]

DIANA: I don't know how many there are and I don't think anybody does.

HANK: Okay.

DIANA: Um. But there's so many types - you can track 'em by radar! Um... There's a massive amount of these tiny little insects.

HANK: Like flying around?

DIANA: Yeah, yeah.

HANK: They're, they're fliers.

DIANA: Yeah. There's just an amazing amount of them.

HANK: Okay.

DIANA: Uh... There are so many that they've killed something like 40 hectares of forest. Forty? Forty million!

HANK: Forty mill...

DIANA: Forty million hectares.

HANK: That's more.

DIANA: That's more than forty. [Laughs]

HANK: That's million times more than forty hectares!

DIANA: Yeah. Hectares of forest just over the last few years in Western America.

HANK: Oh, wow, recently?

DIANA: [Nods] It's big. 

HANK: This this is a huge problem. How long has this been a problem?

DIANA: Well, it depends how you look at it. Mountain pine beetles have been developing outbreaks for millennia.

HANK: Okay.

DIANA: It's native, it's been doing this for a long time...

HANK: So it's sort of like a plague of locusts kind of thing...

DIANA: Yeah.

HANK: Except with trees.

DIANA: Yeah. But recently, ah, over the last 15 years is when we've seen this, this massive kill-off, and it's pretty different than anything we've seen in the past.

HANK: And that is because of...?

DIANA: It's because of the climate.

HANK: Yeah [nodding].

DIANA: So outbreaks are normal but this one is just so much bigger and it has so many different, uh, characteristics. So in this particular outbreak its ten times - actually more than ten times bigger - than anything that's ever been recorded. It's probably the biggest insect outbreak that's ever been recorded on the planet.

HANK: So what we're seeing is they're moving into areas where trees...don't have the same level of resistance?

DIANA: Yeah, yeah. So they're worse in the areas where they've been, but they're also moving into new areas because it's warm enough for them. And that's a really big problem because those trees, you know, they've never had to battle the beetle before, so they haven't really evolved the same level of defenses, and so these trees are just, you know they're like sitting ducks.

HANK: So there's kind of, there's like a kind of immune system against beetles among trees?

DIANA: Oh yeah.

HANK: Trees...

DIANA: Trees aren't sitting out waiting there to get chewed up and killed. 

[Both laugh.]

DIANA: They fight, um, trees are pretty, pretty scary. They have, um, amazing amounts of physical and chemical weapons, I mean, they're really well defended. So it's pretty amazing that something five millimeters long can- can do what it's done.

HANK: Mmhm. Uh, so, what about these little animals do you study?

DIANA: Uh, all sorts of things all the way from...genomes to what they do in, in the ecosystem. But my favorite part is looking at their microbes. 'Cause these insects absolutely cannot do much without their microbes.

HANK: Just like us, really.

DIANA: Yeah, yeah.

HANK: I mean, we can hardly digest anything.

DIANA: Yeah, if you look at the human microbiome it's amazing.

HANK: Yeah.

DIANA: You know, we rely on our bacteria and stuff. These guys...

HANK: There are more bacteria cells in us than us cells.

DIANA: Right.

[HANK stares at camera]

DIANA: And I don't know if that's true for beetles but they've got a few that are really important.

HANK: yeah, I mean if you're eating a tree I imagine that's not a particularly- first, I mean you have the immune system to deal with, second, you're talking about eating a tree like it's not-

DIANA: Yeah.

HANK: Something that I could do.

DIANA: No. Beetles actually can't do it either.

HANK: Okay.

DIANA: They can't eat a tree any easier than us. So, in order to use this tree, they bring in a bunch of partners, so they've got these bacteria in their guts that help 'em right at the beginning, 'cause like I said trees have all theses chemical weapons. And so they've gotta contend with these toxins that the trees produce. Um, you know that really nice smell of a Christmas tree, and so forth? That's the toxins.

HANK: Right, okay.

DIANA: So it's actually, uh...I don't wanna ruin anybody's holiday experience...

HANK: [Laughing] Why- I'm not eating it!

DIANA: Yeah, that's true... Just...smelling it... But, so they've gotta deal with that, and it's poisonous so they have bacteria that break those down. But then once they get past that, you know, then it's cellulose. Well, they can't really survive on that. Um, but they can survive on the little bits of sugars so they get out of the tree-

HANK: Right.

DIANA: But the big thing for these guys is nitrogen. They need nitrogen to make protein, basically build the body.

HANK: Right. Yeah. Nitrogen is...

DIANA: And there's almost none.

HANK: It's al- almost always a limiting factor in an ecosystem.

DIANA: Yeah. Yeah, and especially for insects. So these guys have partnered up with a couple of fungi. And so they...

HANK: Fungi

DIANA: Carry these things, um [laughs]

HANK: So you've got not just bacteria but also fungi, which are amazing at breaking stuff down.

DIANA: Yeah. And...

HANK: You see them growing on dead things all the time.

DIANA: Yeah. Well, what a lot of people don't realize is fungi aren't only good at breaking stuff down, but they can move it around. 

HANK: Mmhm.

DIANA: So these fungi go out into the tree, they gather up all the nitrogen, and then they pump it all the way back to where the beetles are feeding.

HANK: Well, what's in it for the fungi? So they're like, you're just moving all your nutrients to somebody else.

DIANA: Well, I think they probably hang on to what they need, but they move it to where the beetles are because it's in their best interest.

HANK: The beetles can move around.

DIANA: The beetles can move around and the fungi can't. So if the fungi wanna get to the next tree when they run out of food, they have to have somebody to take 'em...

HANK: Keep the beetles alive.

DIANA: So this is their taxi.

HANK: Oh my.

DIANA: Yeah.

HANK: That's a complicated problem. So, uh, like, sounds like you know pretty amazing amount about...this...uh, obviously because they are such a problem. Are there more well-studied bugs in the world?

DIANA: Oh there's a lot more well-studied insects out there.

HANK: Okay.

DIANA: You look at a lot of the agricultural crop pests.

HANK: Okay, yeah.

DIANA: Those are really well known. And I have to say that even after more than a hundred years of studying - not me personally, I'm not quite that old. 

[HANK laughs]

DIANA: Of other scientists studying these insects, ah, we still don't know much about bark beetles. So part of why we don't know a lot about these amazing insects is that most of the research has been on how to kill them.

HANK: Mmhmm.

DIANA: And so we haven't learned a lot about their basic ecology, which is pretty amazing. Ah, but with this massive outbreak we have now as you might suspect, people are getting more interested, and so people are looking at the microbes and all these things, and so we're learning a lot, but it's gonna be a while to understand them.

HANK: Yeah, I mean you talk about how, you know, the most well studied insects are ones that are agricultural pests.

DIANA: Yeah.

HANK: But these are now on the scale that I imagine...the Canadian government is considering them an agricultural pest, because that is huge industry for Canada.

DIANA: [Laughs] Yep.

HANK: Yeah.

DIANA: Canada has put...hundreds of millions of dollars into mountain pine beetle research. They're- they're very concerned about these guys, and it's an ongoing problem for them, because even though in British Columbia, you know, now that the beetle's eaten 80% of the trees in that province-

HANK: [Whistles]

DIANA: Um, it's moving, you know, it's a done deal in British Columbia but now it's moving across Alberta, as an's actually in Saskatchewan already.

HANK: So you say exotic...?

DIANA: Yeah, it hasn't been in that part of Canada before. So...

HANK:, completely unexposed trees that have basically never seen...

DIANA: Absolutely. Not only unexposed trees, uh, but a brand new species of tree, that it's never been in before, so it's in Jack Pine, and that's the main component of our boreal forest, so that, that, that's a big deal.

HANK: It's kinda terrifying. I wou- I would not have thought...

[DIANA chuckles]

HANK: ...that it would be something so small. Um, they're very hard.

DIANA: Yeah.

HANK: They, they make a little noise.

DIANA: Yeah [laughs]

HANK: Can you hear it? [Laughs]

[Both laughing]

HANK: [Drops beetles] Oh God!

DIANA: Oops!

HANK: Haha, they're, oh, now they're all on the ground.

DIANA: Now he's released one into Missoula...who knows what's gonna happen-

HANK: They're super dead!

[DIANA laughs]

HANK: You only brought me the dead ones. I almost got one in my mouth.

DIANA: They're not that bad...uh, we eat them.

[Both laugh]

DIANA: No, no, no, we don't eat the adults because they're kinda tasteless, but, but the larva...

HANK: They don't taste bad, they just don't taste!

DIANA: They don't taste so why eat 'em?! But the larvae that you can take out of the tree? They taste just like pine nuts. And we've actually made pesto out of them. You get the basil and you grind them up. No really, they're not bad!

HANK: I love this so much! That is, I mean, why didn't you bring me...well it's not larvae time.

DIANA: Well, I should have. I can some day, I can bring you some larvae.

HANK: Larvae.

DIANA: The larvae are really good. Um, it takes some convincing for people, but once they've tried 'em...

HANK: I am a super believer in insects as a protein source and a future food source.

DIANA: Yeah, well bark beetles have all sorts of other uses people don't know about. So, you know, as food, you know, you can eat the larvae, you can put them in your pesto. Um, but I actually used to brew beer with yeast that you get out of their mouth parts.

HANK: Wow!

DIANA: And, uh, it's really good beer. It's won an award. I don't do it anymore because I was getting fat, but...

[Both laugh]

HANK: You liked it too much. 


HANK: That's amazing! You removed yeast from a beetle's mouthparts.

DIANA: Right.

HANK: And made beer with it.

DIANA: Several... The first two were total failures, they tasted terrible, uh, but the last one...

HANK: Did you mix it with brewer's yeast, or is it just-

DIANA: No, no.

HANK: Oh wow.

DIANA: I just used it by itself.

HANK: That's amazing.

DIANA: Made some really good porters...

HANK: Oh you're awesome!

DIANA: No, the beetles are awesome.

HANK: Well, and terrible.

DIANA: [Laughs] They're really one of the most interesting organisms on the planet. They have ways to communicate with each other, to mass attack, to use microbes. The things that they do are absolutely amazing. You have to think about this little tiny insect, what it does.

HANK: Gotta have respect for your enemy.

DIANA: That's right.

HANK: Well, that's absolutely fascinating, do you, do we have an animal? [Looks around.] We do?

DIANA: We have an animal.

HANK: Are we gonna, we're gonna, we're gonna share an animal with you.

DIANA: Oh good. 

HANK: Jessi from Animal Wonders is here and I have no idea what's coming. Jessi is here, I'm going to close my eyes and she's gonna but an animal in my hands. I'm gonna guess what it is. [Jessi puts animal in hands.] Ahh... What are, are you, is it something...ooh, it's hard [stroking]. I thought for a second it was like, a mammal but now I, I, so hard not to open my eyes. What are you, are you a bug, a beetle? Are you a-

[JESSI and DIANA smile]

HANK: Is this a giant freaking cockroach?

JESSI: [Laughs and claps] Yeah! Yes, congratulations!

HANK: [Laughs] I thought it was...

DIANA: It's a nice lady too.

JESSI: Yeah!

HANK: I thought it was a mouse because it was so heavy like a small-

JESSI: A mouse?

HANK: A small rodent.

JESSI: A mouse with the little armor [laughs].

HANK: And I touched it and it was not... But it's got little mice-feeling feet.

JESSI: Yeah, [to DIANA] would you like to hold it?

DIANA: Oh sure, I love these.

JESSI: This is Sue, and this is Rick.

HANK: Don't eat it!

[All laugh.]

DIANA: No...I love these...they're so sweet!

JESSI: These are Madagascar hissing cockroaches. Yeah. One of the largest in the world.

HANK: Oh...

JESSI: The largest not the longest.

HANK: I can- I can tell you, that it looks from the front like a regular cockroach. And that's freaking me out. But otherwise, um. I do not- I do not like cockroaches, having grown up in Florida and accidentally killed one on my face once. When I was sleeping.

JESSI: Good story.

HANK: Yeah. But also they smell bad on the inside.

JESSI: Yeah. They smell bad?

HANK: That seems to be what I remember from killing one on my face.

JESSI: Okay, okay.

[HANK and JESSI chuckle]

HANK: Maybe it was just, there was a smell, and because the experience was so bad I associated it with bad things.

JESSI: Okay, well I don't know, these guys don't smell...

HANK: Well not on the outside.

JESSI: Well, well I don't know, they've never smelled bad... I've never stomped one...

HANK: Yeah, well good. You're their caretaker.

[JESSI laughs.]

HANK: But do you, uh, do you, do you keep them around just for showing off, or do you feed anything with them...

JESSI: Yeah, they are multi-purposeful...

[All laugh.]

JESSI: They do educational presentations and they are also feeder- food- you know, feeder insects. So...

HANK: [To RICK] Circle of life, man, sorry.

JESSI: Lizards love them, some of our frogs love them too.

DIANA: Oh...

JESSI: I know, I know...

HANK: When you say 'love' you don't mean the cuddling.

JESSI: No. They have little bugs on them that may love them, but no, they don't love them. They have little bugs you're talking about, bacteria that live with other species. These guys have a little mite that lives on just them.

DIANA: Right.

JESSI: And they originally thought that they were actually going in and like drinking their blood or something, but they don't, they just hang out around the mouthpieces, uh, mouth parts and their legs there and they actually feed on the same food that these guys eat.

HANK: Bugs living on bugs.

JESSI: And they're not bugs!

HANK: These aren't bugs.

JESSI: They're not bugs.

HANK: Wait, what's not bugs? This isn't a bug?

JESSI: This is not a bug [points to cockroach].

HANK: But I thought-

JESSI: It's a colloquial term; it's not a scientific term.

HANK: But is anything a bug then?

JESSI: Yes. There are true bugs.

HANK: Okay. But what makes this not a bug?

JESSI: It does not have sucking mouth parts.

HANK: [gasps] That's...

JESSI:: So all bugs are insects, but not all insects are bugs.

HANK: I feel like that's a plus. Like, I'm glad you don't have sucking mouth parts.

JESSI: Yeah... Cockroaches are pretty terrifying- they're not terrifying really because they can't really hurt us, I mean, they can spread disease, um.

HANK: No, I mean the only scary thing about cockroaches is how fast they move when you turn on the light.

JESSI: They hate light. Yes, the sc- some can fly.

HANK: Oh, oh, oh.

JESSI: He's showing off, how fast he can move!

HANK: That was scary. See, when you start moving quickly, then I'm not happy.

JESSI: So these guys are gonna live in huge colonies; that's what cockroaches do best, and there's over 4000 - there's about 4000 species of cockroaches, 30 of them are gonna be pest species and 4 are really well known, like the German, the American, um, the Asian. Those are like the major pest species, uh, but these guys are not considered a pest species.

HANK: No, yeah.

JESSI: These guys are pretty neat.

HANK: And they're from?

JESSI: Madagascar.

HANK: Oh right, 'cause they're the Madagascar hissing cockroach.

JESSI: So, hissing - how would you hiss? 

HANK: I would - if I was angry? Are you, like why would I?

JESSI: Like how would you physically hiss?

HANK: I would go HHHHH like that, at the back of my throat.

JESSI: Yeah. So they don't have a mouth like us so they can't produce sound like we do. So they have little holes down the sides of their exoskeleton right there where they...

HANK: The little dark area?

JESSI: It's not the little dots.

HANK: Okay that's...somewhere else...

JESSI: Um, it's just like on that crease like on that where they come together kind of.

HANK: Okay.

JESSI: And they're going to breathe through that.

HANK: Oh yeah.

JESSI: Sort of push... What they can do when they hiss is they can take in a lot of air and then they'll squeeze their body together, and they shoot air out the sides of those spiracles, and that's what's causing that hissing noise. And they have different types of hisses, they have um, the threatened hiss, where 'ahhh someone's going to eat me or step on me', you know, 'stay away', um, and then they have the...

HANK: Courting hiss?

JESSI: [Laughs] They do. The 'hey ladies...'

[All laugh]

HANK: [Hisses seductively]

JESSI: Very attractive.


JESSI: These guys- have you heard that they can survive a nuclear blast?

HANK: I have heard that.

JESSI: And, um, they can also survive two weeks without their head.

HANK: Well that...where's their brain at?

JESSI: Good! Yeahhh, it's not in their head, it runs all the way down their body.

HANK: Oh they have a whole, like, spinal brain.

JESSI: Yeah...yeah... So why would they die?

HANK: Right! Well, starvation.

JESSI: Yeah. Can't eat.

HANK: The head's just for eating the food.

JESSI: Just for eating. And seeing. They can see.

HANK: Right. And feeling.

JESSI: So they would just, you know, walk around headless, bumping into walls. But their body would still move, if you call that living.

[HANK and JESSI laugh]

JESSI: Bumping into things. So these guys are pretty popular in p- in, what is it? Popular culture?

HANK: Yeah, okay.

JESSI: Modern culture...? I don't know, um, they are on fear factor shows...

HANK: Right.

JESSI: People are scared of cockroaches and they fill these big tubs with, you know, and they have to lay in the cockroaches.

HANK: So long as you don't have to put it in your mouth.

JESSI: Well, you know, they have eating competitions.

HANK: Yeah, see, I'm not a fan of that.

JESSI: The, um, Guinness World Record for cockroach eating is 36 Madagascar hissing cockroaches in an hour. And the reason...

HANK: That seems like, pretty easy to beat.

JESSI: And the reason you can't eat more is because when they're alive and raw like that they have a mild neurotoxin. So not only do their legs...if you can feel...

HANK: They've got little poker...

JESSI: They have stabbers on their legs there. That's gonna cut your mouth and also your mouth and your throat go numb and so you can't...

HANK: Well.

JESSI: Feel what's going on in there so you can't swallow...

HANK: Maybe...maybe much of that...

JESSI: Not a good idea...don't go...getting into cockroach eating contests.

[All laugh]

HANK: [To RICK] I promise not to eat you. Ever. Unless somebody paid me a lot of money.

JESSI: So these guys aren't beetles.

HANK:  Right.

JESSI: Um, they're in a different order than the beetles.

HANK: How, how can I tell?

JESSI: Um, they're not going to have the sheath wings, the hard outer...

HANK: Right, you don't have wings at all.

JESSI: Wings, yep. But they are in the...

HANK: So beetles have two sets of wings.


HANK: They have the covery wings.

JESSI: The outer. What's it called? El- e...

DIANA: Elytra.

JESSI: Elytra.

HANK: Oh good, we've got an entomologist on the show... And uh, but, but the cockroaches we had in Florida do fly.

JESSI: There are some that have wings. They don't have the outer sheath though, the elytra.

HANK:'s a terrible noise. That they make, when they're flying.

JESSI: Yeah.

HANK: When it's dark and you know that they're there...

JESSI: They're coming to get you.

[HANK and JESSI laugh]

HANK: I love Montana so much!

JESSI: No cockroaches! Except at Animal Wonders.

HANK: That's- That's where they should be. Well, first I have to say thank you to Rick and Sue for coming on the show and being super sweet, um very nice to each other. Thank you Jessi for putting this in my hand. Diana, thank you for your amazing depth of knowledge and just all of your great work on behalf of the forests of North America, and your tremendous respect for those little guys there. Thank you for watching this episode of SciShow Talk Show, if you want to keep getting smarter with us here at SciShow you can go to and subscribe.

[Music plays]