To Bee or Not to Bee
Scientific American, Science Talk podcast
[Original article here; mp3 download here]
In part 2 of our bee podcast, we talk with May Berenbaum, entomologist at the University of Illinois at Urbana-Champaign and inspiration for the X Files fictional entomologist Bambi Berenbaum, about bees, other insects and how life history analysis can make us rest easy during scary sci-fi invasion movies. Plus, we’ll test your knowledge about some recent science in the news
Steve: Welcome to Science Talk, the weekly podcast of Scientific American posted on August 21st, 2009. I’m Steve Mirsky. This week more about bees and all manner of other insect with entomologist, May Berenbaum from the University of Illinois at Urbana–Champaign. Now, last week I promised you that you’d also get a fellow named John Williams, the beekeeper at Darwin’s home in England; however I’m traveling, and I apparently neglected to bring along that audio file, but this problem is easily fixed because what was supposed to be a two-part podcast is now a three-part podcast. I plan to post the William’s chat on Tuesday the 25th of August, so look or listen for that. Meanwhile here’s more with May Berenbaum. Early in our conversation, she mentions Reed Johnson—you’ll recall from part 1 that Reed is her student working on genomes.
Berenbaum: Honeybees, everybody thinks eats honey and pollen, but in reality they feed their grub something called bee bread, which is a mixture of honey and pollen packed into cells, and it cures or ages. And the suspicion is that maybe some of these symbiotic microbes are contributing to the sort of processing of bee bread. So one of the findings from this yet unpublished work that was discussed in Florida at the meeting that Reed attended, Apiary Inspectors of America, was a high-fructose corn syrup which is the preferred diet for overwintering bees because it’s much cheaper than feeding them honey or sugar; apparently it wipes out these potentially symbiotic microbes. One thing that Reed found that’s in his dissertation, when you feed honeybees honey, they upregulate their cytochrome p450 monooxygenases, these enzymes that process among other things plant chemicals, when you give them sugar, it’s nothing. So when you feed them on a sugar diet they are not turning on their chemical processing equipment, so this is something that nobody expected. I mean people aren’t used to thinking of honeybees as broad generalists because they’ll feed on hundreds of different flowers, but in a way they are dietary super specialists because they feed on this narrow range—they feed on pollen, honey and bee bread. And granted the components can come from all different places, but feeding on nectar or honey derived from nectars [is a] very different proposition from feeding on other types of plant tissue because plants load up their vulnerable tissues with chemicals, you know, natural pesticides, so that insects won’t eat them, but they want insects to eat nectar; that’s the whole point [of nectar].
Steve: So it’s possible that this high-fructose corn syrup that’s, you know, partially responsible for the obesity epidemic in humans is also having a devastating effect on the bee population.
Berenbaum: Well, that’s a big jump, but I would say that feeding bees other than honey may have physiological consequences that nobody anticipated. Back in the ’70s the dietary studies were conducted, at least one of the USDA bee labs, and certainly short term there is no longevity effect. And that actually led to the widespread adoption of these alternative diets. But nobody was looking at the microbial symbionts in the gut, nobody was looking at the detoxification enzymes, we didn’t even know to look. So there may be subtle effects. That’s another focus too. As people have for a long time; you know, the way the EPA registers insecticides being safe or unsafe for bees, they do bioassays with adult workers, well adult worker physiology is very different from every other life stage. It’s just really hard to figure out bees. I have worked with caterpillars since, like, 1976. Bees are hard to work with, they are very complicated, they are, I mean they have this amazing social behavior and awareness. Caterpillars are nothing but eating machines, you know. I have seen black swallowtail caterpillars chewing on parsley foliage while the spined soldier bug is sucking out the haemolymph from the other end. They are so intent, all they do is eat, that’s what their, you know, they can increase in size and weight, you know, four to 10,000 fold in a couple of weeks; they eat their weight, their own weight in plant food, that’s what they do. So they have no kind of sense of awareness or recognition of family relationships, so that was one of the really difficult things about doing microarray to determine causes of colony collapse disorder. It’s really a correlative approach, and what complicates things is that you’re looking at genes that are turned on or turned off or turned way up or turned up a little, and there will be genes that are turned on in response to whatever the causative phenomenon might be; but there are also genes whose expression [is being] changed because the social structure [is being] changed. It’s as if you woke up one morning and half of Chicago was gone. Your stress genes would be turned on; that would have nothing to do with whatever wiped out half of Chicago, and that’s what we’re working with microarray. We have the advantage of the human genome; [we] know [a lot] more about what the genes do. So you saw that in the microarray, that big hunk of genes [that] we don’t know what their function is.
Steve: The state of colony collapse disorder understanding is we have a lot of kind of interesting promising, tantalizing leads, but there’s still nothing that we have absolutely pinned down as the cause of this strange disappearance of the bees.
Berenbaum: There are constituencies who feel more or less strongly about the various and sundry causative or contributing factors, but there is no consensus at all and the general perception is that it’s a phenomenon that is perhaps [has arisen] from multiple causes. But one interesting consequence of colony collapse disorder, this was Kim Flottum, he runs Bee Culture magazine, and he has a blog—bee-log—and he remarked that more he has learned about bees in the last two years than in the last 20 and you know this is seriously, seriously overdo. This is a $15 billion industry, I mean, forget the bee is our friend and an inspiration and a model for social behavior, you know; this is a $15 billion industry that has been profoundly neglected, technologically.Steve: And so this could ultimately wind up being a blessing in disguise.
Berenbaum: I suppose. I guess it depends on what the last chapter is, but yeah in terms, in a sense that knowledge is power, yes, absolutely. We have a lot to learn and at least the pace of learning has been stepped up.
Steve: Let’s talk about some of your other work. You do some really fun stuff. Your husband, let everybody know, tell about your husband and the project that you two work on together.
Berenbaum: Well, since 1984, University of Illinois has put on an insect-fear film festival, where we show bad insect science fiction and then explain to people why, what they’re about see can possibly happen. So, we found this to be an incredibly effective mechanism for raising the general level of knowledge and sophistication about insects and …
Steve: Your husband is a film [studies guy]…
Berenbaum: He’s a film professor
Steve: What’s his name?
Berenbaum: Richard Leskosky. In fact, we met because of the Insect Fear Film Festival.
Steve: At Cornell?
Berenbaum: No, no. This was at Illinois. I had the idea for festival when I was a graduate student at Cornell; they thought it was not dignified, so I got my degree and went to University of Illinois, waited a few years to establish my reputation as a solid scientist and then went to the department head and pitched the idea, and he thought it was great.
Steve: You know, I went to Cornell, too. So, we’ll show them who’s dignified. So you do this film festival, I remember reading about; you had an article in the Ecological Society of America’s…
Berenbaum: “Life History Strategies in the Movies”, yeah.
Steve: Briefly explain that to people. That’s really a fun concept.
Berenbaum: Well, we’re now dealing with invasive species. It’s now a catch phrase, or term that a lot of Americans are familiar with. These are species that come from elsewhere and wreak havoc. Typically, invasive species is another name for aliens, you know, nonnative species. Well, movies have been dealing with aliens for a very long time, and I noticed as an ecologist that the life history strategy, the biological attributes of these invading space aliens really would be a recipe for disaster.
Steve: For them?
Berenbaum: For biological, if they were real biological organisms that were intent on invading Earth. Typically, invasive species that are successful are small and extremely numerous; invading aliens tend to be like the size of, you know, [Winnebagos] and relatively few in number. And you can tell from the titles, The Black Scorpion, you know, The Deadly Mantis, and not the hordes of them. They also in movies, tend not to reproduce; [I mean] that is hard to do if you’re, you know, you have biparental sexual reproduction [and] there is only one of you. Which is one reason, I think, that often aliens come to Earth to look for mates. You know, that’s another life history strategy that’s doomed because intraspecific hybridization generally is not a recipe for success, so…
Steve: What was it, Mars Needs Women?
Berenbaum: Right. That probably wasn’t gonna work out too well. This, you know, the hybrid inviability, hybrid sterility, somehow doesn’t apply [to] aliens; Mr. Spock being an exception, I guess—he was half Vulcan and half human.
Steve: Right, but we don’t know if he could reproduce.
Berenbaum: Good point. He could have been the mule of Star Trek.
Steve: You bring up something that I’ve been meaning to get into for a long time and that is that science fiction features a lot of interspecies relationships.
Berenbaum: I don’t know what that says about the movie-going psyche.
Steve: But they look humanoid, so we sort of overlook it, but yes.
Berenbaum: Oh, that’s the other thing, you know, they tend, these movie aliens often are real invasive aliens or small, so they can escape notice, particularly in sort of low budget science fiction films, aliens tend to be about human-size, because that way they can fit into the costume.
Steve: Robot Monster.
Berenbaum: Yeah, exactly. Gosh! It was Monster from Green Hell was about cosmic radiation induced giant wasps and basically they had one and a half giant wasps. They constructed models and just to keep the budget, you know, the cost down. So size, number, reproductive behavior. And then another ecological attribute that differs on screen and in reality is usually the density-dependent mortality sources tend to regulate populations. Generally, particularly in 1950s sci-fi films, it’s napalm, electricity, reversing the polarity, is all these physical factors that don’t really play quite an important a role.
Steve: An exception being, War of the Worlds, where…
Berenbaum: Right, where it was a germ, yeah, a microbe that’s a little bit more—that was not a low-rent movie.
Steve: Right, right. I’m talking about the Gene Barry version.
Berenbaum: Yeah. Well, even that was a step-up from Bert I. Gordon and Beginning of the End and Earth versus the Spider so… .
Steve: Earth versus the Spiders. It got to be a pretty big spider. So …
Berenbaum: It was a giant spider.
Steve: So, if I really want to do a sci-fi movie, that’s sort of accurate about a threat, I have the aliens send a few hundred billion microbes.
Berenbaum: Yeah. Well, yeah that would be certainly one way to do it. Microbes, I think insects would be better, because they’re mobile on their own, lot of microbes rely on vectors to carry them around, they are not quite so mobile. They maybe require water, that’s a vulnerability; you know, cholera for example, you boil the water, you’ll be all right. Or you take the handle off the pump as…
Steve: John Snow…
Berenbaum: John Snow in London. But as our continuing struggle to deal with malaria, which is the leading cause of deaths of kids under 5 worldwide and routinely sickens 200, 300 million people every year, that insect partnership makes it really challenging, control issue.
Steve: Now, let’s tell the story about you. Does anybody still jokingly refer to you as Bambi Berenbaum?
Berenbaum: Yeah. Thanks to TV and the Internet. Yeah, I have to say that I used to carry my Bambi Berenbaum collector card around, because people would come up afterwards ask me to sign there’s.
Steve: They explain who Bambi Berenbaum is and how you got involved and all that?
Berenbaum: There’s an X Files episode called where the “War of the Coprophages” where Mulder is called into investigate mysterious rash of cockroach-related deaths that lead him to suspect that perhaps these cockroaches may be of extraterrestrial origin. Investigating the cockroaches leads him to a USDA facility where he is confronted by Dr. Bambi Berenbaum, USDA entomologist. I first saw the write-up, you know, the blurb in the newspaper, you know, the episode summary; I thought this cannot be a coincidence and I watched the show and it sounds really familiar. And it turns out, it took me a while to track him down, but Darin Morgan, the scriptwriter, for that particular episode had used my books for background research, and he wanted a plausible name for female entomologist, thought Berenbaum worked, Bambi was just kind of icing on the cake, I think. And what’s really nice there’s, you know, stereotypes about entomologists and scientists in general, Coke-bottle glasses which I happen to wear and you know, no sense of fashion or style.
Steve: Let me cover this for you. The Bambi Berenbaum in that show was a very attractive young lady.
Berenbaum: She was a total babe. So, I think that’s fabulous, you know.
Steve: And if I remember correctly, Mulder has a real thing for her.
Berenbaum: There’s a moment where it looks like they might hook up but then she goes off with the genius roboticist, who is wheelchair–bound. I was [rooting] for Mulder.
Steve: You have at least one book out for general audience. Tell us about that book and anything else you might be working on.
Berenbaum: Well, I have two books that are just short essays that are based on a radio show that I used to do locally. One is called Ninety-Nine Gnats, Nits and Nibblers, the other is called Ninety-Nine More Maggots, Mites and Munchers‘ and they’re sort of like little insect profiles. The biggest book is Bugs in the System: Insects and their Impact on Human Affairs, which explains, kind of, how insects have really shaped our lives and our culture and our evolution, which means we shouldn’t ignore them. And then buzzwords and it’s a collection of columns from American Entomologists, humorous essays. In fact, we had a quote from Barry for the cover who said…
Steve: Dave Barry?
Berenbaum: Yeah, the humorous who words the effect of, “If there is a funnier book about insects, I do not know of it.” Because I had actually in one of the essays, I had written about prosthetic legs for cockroaches ended up in one of his columns, and there is a new book coming out in August, Harvard University Press, it’s called The Earwig’s Tail, that’s T-A-I-L. It’s a modern bestiary of multilegged legends. So, bestiaries are medieval collections of usually, well, descriptions of natural life that usually has some sort of moral lesson associated with it. And people believe[d] them completely, even though some of the creatures described were totally fantastic, manticores and unicorns, right next to the rhinoceros. Well, we would like to [think we’ve] progress beyond that point, but in reality the Internet has created a whole new forum of bestiary in these, sort of, urban legends or modern misconceptions about insects; illustrated by the brilliant Jay Hosler, who did Clan Apis, in the style of a bestiary of, oh, “The Brain-Boring Earwig” for example or “The Aerodynamically Unsound Bumble Bee” or, you know, all these convictions people have about insects that actually aren’t true.
Steve: The Brain-Boring Earwig made famous by Night Gallery.
Berenbaum: Well, it goes back further than that. Actually, there’s this longstanding conviction, I know only of two publications that actually document earwigs in the ear, hundreds that document cockroaches. If anything that’s gonna bore through your brain is more likely to be a cockroach. But earwigs, yeah, are not bent on boring through your cerebellum.
Steve: Where are they bent on boring through?
Berenbaum: Kind of depends on the species of earwigs, some of them are like parasitic on bats, you know. But bat ears may be in trouble; but a lot of them are sort of opportunistic feeders, they like sort of moist places. They are well feed on roots and plant, you know, debris [and the like], but nobody eats brains that I know of.
Steve: So, Laurence Harvey was safe all along in that Night Gallery episode.
Berenbaum: Yeah. Well, I mean, movies kind of tap into our inner most fears however ridiculous they are. Just gimme a letter, I can tell you, I’m just trying [to think of] some of the other ones. Oh! Zapper bugs which is about, sort of, the electrocution devices—in reality they’re not killing mosquitoes at all, they’re killing enormous quantities of completely innocuous things.
Steve: There is a fellow at the University of Delaware who did that work.
Berenbaum: Yeah, Dr. Doug Tallamy.
Steve: Right, I remember writing about that years ago.
Berenbaum: And what’s another letter. Oh! the idea that if you pinch your skin while a mosquito is feeding, it’ll explode—[eh,]that doesn’t [work either].
Steve: Now, they can remove that little needle out of your skin, no matter how hard you try to push your skin together.
Berenbaum: There are exploding mosquitoes, but that’s after they’ve been surgically altered, so that the feedback signals that indicate to them that they’re full are interrupted; but that goes beyond most people’s thirst for revenge—getting tiny little tools to severe their nerve cords.
Steve: And that book comes out this summer.
Berenbaum: It’s supposed to be out in August.
Steve: Great! We’ll definitely look for that. Thanks very much.
Berenbaum: Thank you.
Steve: By the way in June, the multitalented May Berenbaum, won first place in the National Pollinator Week Recipe Contest for her dessert called Apiscotti.