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March 21, 2022 - RFK Jr. The Defender

17:29

Mass Decline of Insects with Dr Brian Brown

Dr Brian Brown discusses the mass decline of insect populations globally with RFK Jr in this episode. For more info: https://nhm.org/

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	Hey everybody, I'm really happy to introduce you to today's guest, Dr.
	Brian Brown, who is the head of the Los Angeles Natural History Museum's entomology department and the curator of entomology.
	He has pursued an interest in insects since he was five years old when he created an insect zoo in his backyard in Toronto, Canada.
	Dr.
	Brown received his bachelor's and master's degrees at the University of Guelph, his doctorate at the University of Alberta, and he spent two years as a postdoctoral fellow at the University of Maryland and the Smithsonian in Washington,
	D.C., This specialty is on foreign flies, P-H-O-R-I-D, and particularly a parasitic insect species known as ant-decapitating flies and bee-killing flies.
	And we talk a lot about any issue on this program that affects children's health and is relevant to children's health and I wanted to have you on one because I read a wonderful article about you that was in a Natural Geographic magazine.
	I think you're one of the co-discoverers of these high-altitude insects that are living in the upper canopy of the hundreds and hundreds of new species recently discovered in the upper canopies in the Amazon.
	But also because we've recently been talking a lot about the impacts of certain pesticides on this dramatic decline in insect populations, and particularly winged insects, that has occurred over the past decade.
	And to me, it is as alarming as anything that I've seen or experienced in my lifetime, this mass extinction of the species.
	Yet it's something that is not reported in the mainstream press.
	And, you know, I think that most people don't understand the implications.
	I want to ask you first, why should people like me who are concerned with children's health and the future of our children, why should we be concerned about the disappearance of insects?
	Well, insects are commonly thought of as pests.
	That's the main reason why people don't concern themselves with insects.
	But really, insects help underlie all of the ecological processes on our planet.
	They feed on plants, So they're primary consumers.
	They make energy and plants available for the next growing up.
	So they're important members of food webs.
	They do all kinds of things that we can't do without, such as decomposing, leaves, dead bodies, you know, all kinds of organic material that needs to be cleaned up by something.
	We get that service free from insects all over the world.
	And they're responsible for pollinating our food crops.
	That's just about as important as you can get in terms of ecosystem services and ecosystem processes.
	So they help provide us with clean air, water, food, all those sorts of things that we take for granted every day.
	They're just everywhere.
	And that's because they're important in everything.
	I can't imagine how we would have a group of animals that are more important than insects.
	Now you have to remember that the group you say you're interested in birds, the group of insects I work on is bigger than all the birds It's just one family of flies.
	I'm talking about the number of species in the group.
	So the amount of knowledge that you have to have to recognize all the foreign flies exceeds what you would have to have to know all the birds.
	Somebody like me who works on one family of insects cannot possibly be expected to know all the genera of beetles, for instance, or whatever.
	And beetles are the biggest genre.
	The beetles are the biggest order of insects currently.
	But from studies like the ones we did in the Amazon on the tower, we see that the number of flies is actually way larger than what we previously thought.
	And it's because these things are small and obscure and they're not collector items that people have been looking at since Charles Darwin's time or Even earlier, but they're really poorly known.
	There's one family called the gall midges, or Cicidomyidae in the Diptera of the true flies, that could be the largest family of insects.
	There's estimates of a million species of gall midges alone, and forehead flies are right behind them.
	There are about half as many forehead flies at a site as there are gall midges.
	And give us a quantitative notion about this dramatic past extinction that's taking place.
	We had a guest on here recently who said, I think 80% of winged insects have disappeared over the past decade.
	Could that possibly be true?
	Well, what the data show is that The numbers of insects have greatly declined.
	That's not necessarily the species have gone extinct, but the numbers are down.
	It may be true that there are species that are going extinct at the same time, but there is not good evidence for that.
	What there is evidence for is that backyard porch lights that used to be covered in moths and other insects at night, or people's windshields when they're driving across country that used to be splattered with bug guts, Are no longer showing that same situation.
	I mean, people are driving across the country and hardly having any insects collide with their car.
	It's kind of a gross and unappealing way of gauging the loss of a portion of our ecosystem, but it is one that we actually notice.
	And the same with the porch lights.
	I mean, insects are not coming to lights in backyards or insect traps or in Other situations where they used to come in anywhere near the same numbers.
	So the number of insects of certain species have been documented as declining very, very precipitously.
	But not necessarily the loss of the species.
	That may be happening as well, but that hasn't been documented as well.
	And who is culpable?
	Who is most culpable?
	Or who are the villains here?
	The phenomenon is worldwide.
	This sort of response is an overall response to wide-ranging causes.
	There's pesticides is certainly part of it.
	Habitat loss is a big part of it.
	I mean, we've cut so many forests and made agriculture so intense that there's no room for nature, for populations of insects.
	And climate change as well that's tending to make our climate less reliable for insects that are extremely tuned into environmental cues for their reproduction and their feeding.
	Let's talk about the Amazon.
	Okay.
	Were you actually on that trip to the Amazon, or are you just looking at the collections?
	No, the Amazon project that we have is looking at insects from a tower.
	In the Amazon.
	So the tower goes from the ground all the way up to the top of the canopy and above it.
	So it's about 40 meters tall.
	And one of my colleagues in Brazil put insect traps every eight meters on the tower and we were able to observe how different insects lived at different levels in the canopy of the forest or in the forest.
	We found such amazing things In the upper levels that it made me say that while this is just like discovering a new continent, the things are so different and so special that are found in those different elevations.
	So we went down there to study some more on the tower.
	To try and figure out some life histories of some of the species that were there and to make further observations.
	I mean, there's just so much to do just on one level of the forest that it would take a lifetime to do it.
	So we're still in the early discovery stages of that.
	And if you named any of these new insects after yourself, yeah.
	Well, that would be an exceedingly bad taste.
	Let's talk about bees for a second, because I think most people understand the importance of bees.
	You study an insect that actually kills bees, but what are you seeing in terms of bee populations globally?
	Well, we have to separate the honeybee from the native bees.
	So the honeybee is a species that's native to Asia and Southern Europe that's been brought here to North America as an agro-ecosystem tool.
	It's basically used to raise the pollination levels of our crops to produce more food per acre.
	This makes our agriculture more economically feasible and sustainable because we can grow more food, obviously, Per acre by using honeybees to get in there and pollinate everything.
	Those honeybees are extremely important for our agriculture.
	Whenever there's some kind of problem with honeybees and their populations, it directly affects our well-being.
	But there's the other types of bees, the native bees.
	Here in California, we have maybe I don't know, a thousand species of native bees in addition to the honeybee.
	So when people say that they're concerned about bees and the environment, I always have to separate those two out.
	Honeybees have been used for agriculture for many, many years, of course, and they're great because they'll pollinate any kind of plant.
	So you can move them, just pick them up from your bee yard and take them out to the almond grove and get those pollinated.
	And you can pick them up and move them over to I don't know, whatever else you want to pollinate, alfalfa, and they'll pollinate there, then take them out to somewhere else, they'll pollinate that crop.
	Whereas native bees are usually quite closely tied to certain native plants in terms of their activity periods and their behavior that's extremely coordinated with the plants in order to pollinate them.
	So which bees are you asking me about?
	Oh really, tell us a little bit about the parasitic that eats, that decapitates bees.
	The fly that you're talking about is what we call the zombie fly because it, well, it's like other parasitic forward flies.
	The female fly lays an egg inside the bee's body.
	The egg hatches and the larva feeds on the contents of the bee's body, eventually killing it.
	That's a lifestyle we call parasitoity or parasitism in insects.
	You know, there's three types of carnivory in insects.
	There's predators that kill many hosts, like Think like a lion.
	That's one type.
	There are parasites that feed on one host but don't kill it.
	That's like a bot fly that gets into the skin.
	And then there's parasitoids that feed on one host and they kill it.
	So those are three levels of carnivory we have in insects.
	We don't have the parasitoid in invertebrates, so it's not something we're as familiar with.
	So anyway, these flies will lay their eggs inside bees, and the bee, as it's starting to go downhill from the feeding of the parasitoid, will start doing strange things, like not come back to the nest like it's supposed to.
	They'll be attracted to lights at night.
	It's unclear what's going on there.
	In some Systems where parasitoids have other effects on their hosts, like they cause them to behave differently.
	This helps the parasitoid in its life cycle.
	But like I said, we don't really know what's going on.
	These flies definitely are attacking honeybees.
	That's a switch that has to have taken place in the last few hundred years, because honeybees weren't present in North America before that.
	They were brought here by Europeans for agriculture.
	So the flies attack bumblebees, native bumblebees, and they've switched over to honeybees.
	So the concern is that these flies may be contributing to the problems that the honeybees are having with agriculture.
	And maybe if they're exported to other countries, they might cause even more problems.
	So it's something to be very concerned about in terms of the bee pollination business.
	Well, I hike almost every day in the Santa Monica Mountains, and one of the fun parts of my hike is that I use iNaturalist, which is an app that was created by National Geographic and the Smithsonian Institute, where you can take a photograph of almost any living organism.
	And it will identify it, and then it credits you with the find, and it puts that find, including the date and the species, into an international database that's doing essentially a biological inventory of the planet.
	A very, very useful baseline for what the planet is supposed to look like, and When the flowers bloom, when the species appear, migratory species, etc.
	Do you use that?
	Do you ever use that in your research?
	A little bit.
	The flies I work on are in the small end for iNaturalist.
	So I would say one thing about your characterization of iNaturalist is that the app doesn't identify the animals, at least not yet.
	People identify the animals.
	People like me who are experts on foreign flies, for instance, would go through there once in a while and pick out things that I can identify or that I want to identify and put names on them.
	So I've found a few interesting things that other people have posted there, like hosts of parasitic species where we didn't know the host before.
	So people have photographed them laying eggs in ants or bees.
	That we didn't know what they attacked before or mating behavior that I hadn't seen before.
	So it's a great tool for documenting these behaviors.
	For inventory, it's not as good because the flies are so small, we usually have to dissect them or we have to sequence them with DNA barcoding in order to figure out what species they are.
	One of the things that you have a history of doing at the museum and at the urban playground is identifying, focusing people and getting people excited about local insects.
	Can you tell us a little bit about that?
	Yeah, it's fascinating to me what lives in people's backyards and gardens, because, you know, most people are unaware.
	So they should be.
	I mean, they've got better things to worry about than one millimeter long flies.
	But if we put our insect traps in their backyards, we can see how biodiversity is affected by different types of urbanization, you know, whether or not you have native plants, whether or not you have your house is close to natural areas.
	Or if there are things you can do to increase the biodiversity of your backyard.
	Here in Los Angeles, we found that actually putting less water on the landscape is one of the best ways to increase your biodiversity, which makes sense because the natural environment is a dry one.
	We not only gone out and found what's common in backyards, but we've also described close to 50 new species of foreign flies and other flies in Los Angeles.
	Which is pretty astonishing when you consider that, you know, there's that much undescribed biodiversity in a big city full of millions of people.
	We talk a lot about doom and gloom on the show, not because it's my implication, but because the subject matter that we address are things where, you know, there's a lot of alarming things going on in the world.
	Can you tell us any kind of message for optimism or hope?
	Well, I can tell you why I like to study insects, and I think why other people like to study insects is because there is an almost inconceivable number of species out there.
	There are so many new things to discover that you can still, you can never go tired of looking at insects from any part of the world.
	You still have a likelihood of finding new things, and there's still so much exploration to do.
	We are losing biodiversity rapidly around the planet, but there's still a lot to see and to enjoy.
	Well, Dr.
	Brown, thank you so much for joining us.
	Tell our listeners how people can support you or how they can visit your facility.
	Well, we'd love to have people come to the museum and see photographs of insects and specimens of insects.
	It's the Natural History Museum in Los Angeles and nhm.org.
	Thank you very much, Dr.

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