Dr. Brian Brown is the head of the Los Angeles Natural History Museum's entomology department and the curator of insectogy at the National Museum of American Natural History in Washington, D.C. Dr. Brown is also the co-discoverer of a new species of high-altitude insects that are living in the Amazon, and he is one of the world s leading experts on the decline in the number of winged insects. In this episode, he talks about why we should be concerned about the disappearance of insects, and why they are so important to our environment and our future. This episode is brought to you by Entomology, a division of the Natural History museum, and the Center for Integrative Biology and Evolution at the University of Southern California, Los Angeles, which focuses on the study of insects and their interactions with other life forms, such as birds, bees, butterflies, moths, butterflies and other insects, among other things. We hope you enjoy the episode and share it with your friends, family, colleagues and the rest of the insects you care so much about! Thank you so much for your support of this podcast and for your continued support of our efforts to make a difference in our field and in the world. We can't wait to do more of these amazing programs. Thank you for all the support, and we'll see you next week for the next episode of the podcast, "Insects are the lifeblood of our planet" on Tuesday, July 31st! by The Nature Conservancy in the new issue of the New York Times. . Thanks to our sponsor, Subscribe to our new podcast "Outdoor" and stay tuned for all things bug-related! ! to the next week's episode of Outdoor Life! and keep us up to date with all sorts of things out there! Stay tuned for the latest in the Outdoors and Outdoors! on social media! , and stay safe out there on the road, and stay green! . . . and Stay safe, and keep safe, be safe, Stay green, Earthlings! Love Birds, Birds, Stay Green, Stay Out of the Woods, Stay Weird, Stay Plush, Stay Wild, Stay Scared, Stay Blue, and Stay Green! Cheers, Cheers! - Eternally Cheers - John Rocha, Caitlyn
00:00:23.000Brown 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,
00:00:40.000D.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.
00:00:57.000And 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.
00:01:17.000I 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.
00:01:31.000But 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.
00:01:49.000And to me, it is as alarming as anything that I've seen or experienced in my lifetime, this mass extinction of the species.
00:02:00.000Yet it's something that is not reported in the mainstream press.
00:02:05.000And, you know, I think that most people don't understand the implications.
00:02:09.000I 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?
00:02:22.000Well, insects are commonly thought of as pests.
00:02:27.000That's the main reason why people don't concern themselves with insects.
00:02:32.000But really, insects help underlie all of the ecological processes on our planet.
00:02:39.000They feed on plants, So they're primary consumers.
00:02:45.000They make energy and plants available for the next growing up.
00:02:48.000So they're important members of food webs.
00:02:51.000They 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.
00:03:03.000We get that service free from insects all over the world.
00:03:08.000And they're responsible for pollinating our food crops.
00:03:12.000That's just about as important as you can get in terms of ecosystem services and ecosystem processes.
00:03:19.000So they help provide us with clean air, water, food, all those sorts of things that we take for granted every day.
00:03:30.000And that's because they're important in everything.
00:03:32.000I can't imagine how we would have a group of animals that are more important than insects.
00:03:36.000Now 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.
00:03:46.000I'm talking about the number of species in the group.
00:03:51.000So 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.
00:03:59.000Somebody like me who works on one family of insects cannot possibly be expected to know all the genera of beetles, for instance, or whatever.
00:04:12.000The beetles are the biggest order of insects currently.
00:04:16.000But 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.
00:04:29.000And 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.
00:04:43.000There's one family called the gall midges, or Cicidomyidae in the Diptera of the true flies, that could be the largest family of insects.
00:04:53.000There's estimates of a million species of gall midges alone, and forehead flies are right behind them.
00:05:00.000There are about half as many forehead flies at a site as there are gall midges.
00:05:04.000And give us a quantitative notion about this dramatic past extinction that's taking place.
00:05:12.000We had a guest on here recently who said, I think 80% of winged insects have disappeared over the past decade.
00:05:24.000Well, what the data show is that The numbers of insects have greatly declined.
00:05:31.000That's not necessarily the species have gone extinct, but the numbers are down.
00:05:37.000It may be true that there are species that are going extinct at the same time, but there is not good evidence for that.
00:05:44.000What 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.
00:06:01.000I mean, people are driving across the country and hardly having any insects collide with their car.
00:06:07.000It'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.
00:06:20.000I 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.
00:06:31.000So the number of insects of certain species have been documented as declining very, very precipitously.
00:06:39.000But not necessarily the loss of the species.
00:06:42.000That may be happening as well, but that hasn't been documented as well.
00:07:05.000I mean, we've cut so many forests and made agriculture so intense that there's no room for nature, for populations of insects.
00:07:15.000And 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.
00:07:50.000And 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.
00:08:03.000We 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.
00:08:20.000So we went down there to study some more on the tower.
00:08:24.000To try and figure out some life histories of some of the species that were there and to make further observations.
00:08:31.000I mean, there's just so much to do just on one level of the forest that it would take a lifetime to do it.
00:08:39.000So we're still in the early discovery stages of that.
00:08:43.000And if you named any of these new insects after yourself, yeah.
00:08:46.000Well, that would be an exceedingly bad taste.
00:08:50.000Let's talk about bees for a second, because I think most people understand the importance of bees.
00:08:55.000You study an insect that actually kills bees, but what are you seeing in terms of bee populations globally?
00:09:02.000Well, we have to separate the honeybee from the native bees.
00:09:05.000So 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.
00:09:16.000It's basically used to raise the pollination levels of our crops to produce more food per acre.
00:09:23.000This 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.
00:09:34.000Those honeybees are extremely important for our agriculture.
00:09:39.000Whenever there's some kind of problem with honeybees and their populations, it directly affects our well-being.
00:09:46.000But there's the other types of bees, the native bees.
00:09:50.000Here in California, we have maybe I don't know, a thousand species of native bees in addition to the honeybee.
00:09:57.000So when people say that they're concerned about bees and the environment, I always have to separate those two out.
00:10:05.000Honeybees have been used for agriculture for many, many years, of course, and they're great because they'll pollinate any kind of plant.
00:10:12.000So you can move them, just pick them up from your bee yard and take them out to the almond grove and get those pollinated.
00:10:19.000And 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.
00:10:30.000Whereas 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.
00:10:44.000So which bees are you asking me about?
00:10:48.000Oh really, tell us a little bit about the parasitic that eats, that decapitates bees.
00:10:56.000The fly that you're talking about is what we call the zombie fly because it, well, it's like other parasitic forward flies.
00:11:03.000The female fly lays an egg inside the bee's body.
00:11:06.000The egg hatches and the larva feeds on the contents of the bee's body, eventually killing it.
00:11:12.000That's a lifestyle we call parasitoity or parasitism in insects.
00:11:17.000You know, there's three types of carnivory in insects.
00:11:20.000There's predators that kill many hosts, like Think like a lion.
00:11:27.000There are parasites that feed on one host but don't kill it.
00:11:30.000That's like a bot fly that gets into the skin.
00:11:33.000And then there's parasitoids that feed on one host and they kill it.
00:11:37.000So those are three levels of carnivory we have in insects.
00:11:40.000We don't have the parasitoid in invertebrates, so it's not something we're as familiar with.
00:11:46.000So 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.
00:12:01.000They'll be attracted to lights at night.
00:12:06.000In some Systems where parasitoids have other effects on their hosts, like they cause them to behave differently.
00:12:13.000This helps the parasitoid in its life cycle.
00:12:17.000But like I said, we don't really know what's going on.
00:12:20.000These flies definitely are attacking honeybees.
00:12:24.000That'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.
00:12:31.000They were brought here by Europeans for agriculture.
00:12:34.000So the flies attack bumblebees, native bumblebees, and they've switched over to honeybees.
00:12:42.000So the concern is that these flies may be contributing to the problems that the honeybees are having with agriculture.
00:12:51.000And maybe if they're exported to other countries, they might cause even more problems.
00:12:56.000So it's something to be very concerned about in terms of the bee pollination business.
00:13:01.000Well, 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.
00:13:20.000And 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.
00:13:37.000A 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.
00:14:07.000People 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.
00:14:17.000So 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.
00:14:26.000So people have photographed them laying eggs in ants or bees.
00:14:31.000That we didn't know what they attacked before or mating behavior that I hadn't seen before.
00:14:37.000So it's a great tool for documenting these behaviors.
00:14:41.000For 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.
00:14:54.000One 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.
00:15:06.000Can you tell us a little bit about that?
00:15:08.000Yeah, it's fascinating to me what lives in people's backyards and gardens, because, you know, most people are unaware.
00:15:17.000I mean, they've got better things to worry about than one millimeter long flies.
00:15:20.000But 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.
00:15:34.000Or if there are things you can do to increase the biodiversity of your backyard.
00:15:39.000Here 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.
00:15:51.000We 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.
00:16:03.000Which is pretty astonishing when you consider that, you know, there's that much undescribed biodiversity in a big city full of millions of people.
00:16:11.000We 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.
00:16:26.000Can you tell us any kind of message for optimism or hope?
00:16:31.000Well, 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.
00:16:43.000There 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.
00:16:53.000You still have a likelihood of finding new things, and there's still so much exploration to do.
00:17:00.000We are losing biodiversity rapidly around the planet, but there's still a lot to see and to enjoy.