Queens, DCAs, and Africanized Honey Bees with Chip Taylor and Gard Otis (370)

370 - Queens, DCAs, and Africanized Honey Bees with Chip Taylor and Gard Otis

Doug Burton: Hi, this is Doug Burton from Lexington, Kentucky. Welcome to the Beekeeping Today Podcast.There we go.

Jeff: You got it.

Doug: We're going to use it this time, aren't we? [laughs]

Jeff: Yes, I will use it.

[music]

Jeff Ott: Welcome to Beekeeping Today Podcast presented by Betterbee, your source for beekeeping news, information, and entertainment. I'm Jeff Ott.

Becky Masterman: I'm Becky Masterman. Today's episode is brought to you by the bee nutrition superheroes at Global Patties. Family-operated and buzzing with passion, Global Patties crafts protein-packed patties that'll turn your hives into powerhouse production. Picture this: strong colonies, booming brood, and honey flowing like a sweet river. It's super protein for your bees, and they love it. Check out their buffet of patties, tailor-made for your bees in your specific area. Head over to www.globalpatties.com, and give your bees the nutrition they deserve.

Jeff: Hey, a quick shout-out to Betterbee and all of our sponsors whose support allows us to bring you this podcast each week without resorting to a fee-based subscription. We don't want that, and we know you don't either. Be sure to check out all of our content on the website. There, you can read up on all of our guests, read our blog on the various aspects and observations about beekeeping. Search for, download, and listen to over 300 past episodes, read episode transcripts, leave comments and feedback on each episode, and check on podcast specials from our sponsors.

You can find it all at www.beekeepingtoday.com. Hey, Doug Burton, thank you for that wonderful opening from the floor of North American Honeybee Expo just a few short weeks ago, Becky.

Becky: Jeff, you did such a good job recording all those openers, and I'm so glad you've never trained me how to use the technology to record the openers. I just kept pointing to you all weekend long. One of my favorite parts of being there was having people who you've recorded other openers with who came up, and they were so thrilled to hear their opener open an episode.

Jeff: There's a couple in a couple weeks that we'll hear them, and they'll say, "Well, I left an opening last year. Can I do one this year?" "Absolutely." I think we have some three repeats in there, too. That's fun.

Becky: It's a great tradition.

Jeff: It is. Thanks, Doug. Doug harassed me about not using his opener from last week or last year. Sometimes there's technical issues. Doug, appreciate you coming back.

Becky: Yes, I'm glad he gave us another chance, and I like how you just put them straight to the front of the line.

[laughter]

Jeff: Becky, speaking of North American Honeybee Expo, that was such an amazing experience. Now that you've had some time to reflect on it, what is your greatest takeaway from the experience?

Becky: I met a lot of really, really special people, or I was able to reconnect with them after last year. I just think that getting to know beekeepers from across the country and across North America, it's quite the opportunity because it feels like this conference gives you the ability to have those conversations with people. It helps that we're standing in a booth, but it feels like there's space for people to really get to know each other. I just love those connections.

Jeff: I do like and enjoy the positive atmosphere of the experience and being on the floor and talking to so many happy people or even seeing the people walking by and being really happy.

Becky: Yes, the thank yous are wonderful.

Jeff: Yes, that is so funny. There's so many people walking by, barely making it to the door with their load of equipment. It was almost comical, but I understood the strain that they were under. It was good, so I'm glad we were able to experience it.

Becky: I've got another favorite too. Oh my gosh, Dr. Jim, too, and Honeybee Obscura, and his fan base is exceptional. I knew it was going to happen, and it did. I'm okay with it, but the number of people, when Jim actually took a quick break and maybe was walking around the floor, but he would start piling up people saying, "Is Dr. Too here? Is Dr. Too here?" [chuckles]

Jeff: Where's Dr. Too? Then there's a couple of people that just circle around and they'd be back and they'd start talking to him again. I think that was wonderful and very happy that we were able to meet so many very fine beekeepers. It's the first week of February. Are you doing anything with your bees yet? Have you been able to get into them?

Becky: I am giving them good vibes.

[laughter]

Becky: I'm thinking about them.

Jeff: You're hitting the little bowl.

Becky: I don't even have actual access for a couple of my bee areas just because of snow and everything. No, I'm really anxious. It's time soon but not here. Again, all those beekeepers and the warmer climates, they know how their girls are doing. Every once in a while, I'll zip out to an apiary that's accessible just to not even open them up, but just go, "Yes, okay, you're there. Great." That's it. What about you? You can see your bees, the inside and out, right?

Jeff: I haven't opened anybody up yet or any of the live colonies yet. I can see which colonies I've lost, at least the ones where I've had sensors on them. That's always disappointing and distressing, but it's part of beekeeping these days. I'm looking forward to the spring. Already, in January, we had bees bringing in pollen from the hazelnut. That's always fun to see in this area. In January, it's always a great thing to see.

We'll come back with wet days again in winter, and it's back and forth. As we get into this month of February, things will start transitioning to a more stable springtime for us, weather, and it's warmer days, and the bees will get out on the nicer ones. It's fun to see, and I'm glad we're finally on this downhill side of the temperature swing.

Becky: I'm just going to mention it. It's new beekeeper time, too. I actually have the opportunity. I get to teach a little bit at the University of Minnesota short course, the beekeeping class. Also, I was invited to speak at the University of Wisconsin-Madison. They've got a new beekeeping short course, and so I get to talk a little bit about colony health at that one, and that's actually Valentine's Day weekend. That's coming up really close. Welcome to the new beekeepers out there who are listening to us. We're really excited that you're joining us.

Jeff: Speaking of new beekeepers and events coming up, we will be at the Midwest Honeybee Expo this weekend in Madison, Wisconsin. I'm really looking forward to that.

Becky: I've got two weekends in Madison, right, in a row. Pretty exciting.

Jeff: You might as well set up a tent there. [chuckles]

Becky: Right. I love it. I told all the Wisconsinites at their Wisconsin picture at Navi, I said, "Both my parents were born in Wisconsin. I should be able to get into your picture."

Jeff: That's great. All right. We have a big episode today. We have returning to us Drs. Chip Taylor and Gard Otis. They were with us last summer talking about drone congregation areas, DCAs, queens, and honeybee mating. It's a really fascinating talk, and we had many people who were wanting to hear from these two this last six months.

Becky: Yes. I can't wait to talk to them again. I love everything that is in their minds because if they didn't do the research, they know who did it, and they can tell us about it. We're going to learn a lot, Jeff. This is great.

Jeff: I'm looking forward to it. Now, just a little disclosure here. Back in 1993, I was able to visit Dr. Chip Taylor and Dr. Roger Huppengardner in their lab in Linares, Mexico. They were just studying the Africanized bees had just crossed over the Rio, but they still had a lab there trying to answer some questions. It's going to be really interesting to see how some of those early concerns, how they've transpired, how they've materialized as time has progressed. That's when? 33 years ago? Wow.

Becky: Been a long time.

Jeff: It's been a long time. It's hard to believe it's been that. With that in mind, when we come back, we will continue our discussion with Chip and Gard, and after this quick word from Bettebee.

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Jeff: Hey, everybody. Welcome back. Sitting around this great, big virtual Beekeeping Today Podcast table. It's almost a repeat episode. If you remember last summer, Episode 342, if I remember correctly, we had Dr. Chip Taylor and Dr. Gard Otis with us talking about the impact of the Africanized honeybee on the North American honeybee industry. I encourage you to go back and listen to it. Guys, welcome back to the show.

Dr. Chip Taylor: Hey, great to be here.

Dr. Gard Otis: It's good to be here, too.

Jeff: Last time that you were on last summer, you gave us a great history and background on DCAs and mating behaviors. Then we ended on Africanized honeybee. That drew a lot of questions and comments.

from our listeners, and we wanted to have you back to continue the discussion and just further explore this topic because we don't hear too much about Africanized honeybees anymore.

Becky: Hey, Jeff?

Jeff: Sure.

Becky: Remember, we've got those brand new beekeepers in the audience, and so they're Googling DCA right now. We bring everybody together.

Jeff: That was not a reference to DC-8 as the airplane. It's DCA, Drone Congregation Area.

Becky: You really opened up our minds to what drone congregations are and maybe are not. Maybe you could summarize that for our new and returning listeners.

Gard: Honeybee mating is, I'd say, rather unique in the animal world. As most of you probably realize, both honeybee queens and drones leave their colony. They fly out into the landscape. At that point, it's really, really hard to know what happens because it's hard to track individual bees. With the drones, we've been able to track. Chip was involved in early radar studies where they couldn't identify individuals, but they could tell where drones were in the landscape. It matched in some ways what we had known about bees, that there are sites in the environment where, in most landscapes, drones congregate in the air. It's said that they wait for queens there. That's what's been said in the past.

Chip's research showed that there were flyways and that it looked like drones were flying out along landscape, following landscape features, and flying out from one drone congregation area to the next, to the next. That sat for many, many years until just, I don't know, four years ago or so, some researchers in the UK were able to use harmonic radar where they could track individual drones. That's great, except the harmonic radar only tracks them about 800 meters, and we know that some of these drones are flying 4 to 5 kilometers, and that's 3 miles. They could track them to some of these areas where they could see congregations of drones from all their maps together.

It's clear that there are places where drones tool around, and they seem to aggregate, but it isn't clear if they're doing that because they're going there because that's where mating occurs or if that's where they go because they need to reorient and change direction and fly off to another direction where they then reorient again at another aggregation point. That's what we're left with. In Queens, we've not been able to track at all up to this point. We really have this vague sense.

Most people think that mating occurs at these drone congregation areas, and probably a lot of it does because there's high densities of drones there. Then there are landscapes where drones are everywhere. They don't form any congregation areas, and mating probably occurs all across the landscape. I just published a paper, it was In Apidologie that's open access, so anybody listening to this can access it. Basically, it summarized all this, what we know about drones and where they fly and where mating occurs.

The final thing I was trying to get across is we don't know, and it would be nice to know because it's hard to control matings if you don't know where they're happening or how far the bees are flying in different landscapes. It was really a way to try to stimulate more research by researchers to sort out some of these questions. I don't know if you want to add anything to that, Chip.

Chip: Yes. Just a couple of things. Drones are apparently learning the environment, and they're going further and further as they get older. If you do this type of tagging that we did and painting on drones that we did so that we had age-specific knowledge of these drones, you can see that drones, when they first fly out at about eight or nine days, are only going about maybe 800 meters or so. By the time that they're 40 days old, if they live that long, and most drones don't, they're going out there 3 to 4 kilometers. They're learning the environment progressively, and this is interesting. Why would they do that? They certainly do not spend very much time in each individual congregation area. It's a very dynamic process.

One of the things that you might imagine is, what does it take in this particular system to achieve a degree of outbreeding? One of the things that we've established with the various tests that we've done is that the average drone is from a given colony or apiary. The average effective genetic distance of those drones is about 0.5 mile. It appears that the queens are actually flying further than that. That effectively allows the bees to outbreed and to avoid mating with their brothers, which is just the way it should be. What I don't know is how queens go 1 mile and avoid all of the nearby congregation areas.

Gard: Or 2 or 3 miles, because in some settings, they go a long distance.

Chip: The queens have got a different routine than the drones do. That's a puzzle. How do they avoid mating until they get a fair distance away from drones from their own colony? That's a real puzzle. This is why, as Gard said, it would really be nice to be able to track queens, which we can't do yet. Maybe a harmonic radar will take them out there over 800 meters, but that's not enough. We need to know what they're doing beyond 800 meters.

Gard: I'm hoping those guys you worked with on tracking the monarchs will collaborate. It turns out that a queen weighs about 200 milligrams, and the little tags weigh about 30 milligrams. No, 60. They're about 30% of a queen's weight. Can a queen fly and carry 30% of her weight? I think so. If she could, we can put them on there, and we can track those little queens all over the place. You know how to do that because you did it with monarchs.

[laughs]

Jeff: Would that restrict their distance?

Gard: It might limit their flying somewhat. I wish they could get them down to half that weight. That'd be better. Was it 60 milligrams or 30? I think it's 60.

Chip: 60 is the average weight of these things now. [crosstalk] They could be reduced, but I would put them on drones first.

Jeff: I wonder how much air resistance that creates on their bodies, too, that would slow them down.

Gard: I know there's all these issues. It's borderline. If they could just get them down a little smaller. Anyway, we're going off track. I think we're getting really close to being able to track them one way or another. Again, that's part of the reason. Actually, several people I know saw that monarch stuff, Chip, and they contacted the company just like I did. There's a bunch of people like, "Whoa, did we do this?" There's interest.

Jeff: What is the most prevalent misconception about honeybee breeding and queens and drones that you see repeated time and time again?

Chip: I would say that they mate in congregation areas exclusively.

Gard: I would say that they mate in congregation areas because we don't know that. It's been assumed that. Almost everybody writes that in papers and all their teaching about bees and everything, that the drones go out, and they wait at a congregation area for queens, which we know from these radar studies isn't the case. They keep moving from place to place to place. Then the queens somehow fly out and search for those males. They mate with them and go home, but we've never been able to follow a queen to know that that's what they do. It's a myth.

Becky: Jeff and I just wrote a beginning beekeeping book, and we were so careful about our language when it came to queen and drone mating because of the two of you, and we cited that actual podcast, too. I have a question, if we could back up just a little bit. You talked about that we don't know how the queen makes it through the drones before she actually mates. Am I right in that you hypothesized it could be the height that she's flying?

Gard: I didn't hypothesize that, but some people have, that queens fly lower, and they fly below the drones until they want to mate. Then they fly up. Again, we have no evidence of this. I don't know where that came from, but somebody saw a queen one day flying low, and they came up with this. I don't know.

Chip: That's one of the ways that could be done. That's the easiest way to explain what's going on, but here's another thing that's of interest. One day, during a class, I had about 10 virgin queens and a ladder, which I took out to a known drone congregation area. I let those virgin queens go from the top of the ladder just between my fingers as they came out of the queen cage. They flew in this congregation area with a lot of drones. We were at the peak of the drone flight.

Within about five or 10 minutes, comets began to form. It was amazing to see these comets in the congregation areas. These queens were pursued one after another, but they all came back to me at the top of the ladder. They crawled between my fingers and went back in their queen cages. When I checked them, not a single one had ever mated.

Becky: They went on orientation flights.

Chip: Well, effectively, they went on orientation flights, but they were pursued by 30 or 40 drones over and over again, and not a single mating. That told me is that they know when they want to mate, and they're not going to mate just because a bunch of guys are chasing them.

Becky: They have control. You've just answered who's in charge with a sample size of 10. I like it.

[laughter]

Chip: That's right.

Becky: That's how science is done, right? Is that you do these observations, and then you figure out a way-- Wait, if we want to investigate this more, how do we set this up?

Gard: We do know that the queen has to open her sting chamber and allow the male to mate with her. She has some control. Now, whether she exercises control about which male she's going to allow to mate and which one she isn't or how she does that, we don't know, like Chip said.

Jeff: Does she release a different pheromone when she's ready to mate? The drones were attracted to the queen when you released them, but she wasn't receptive. When she's receptive, do they know that, or is there another queen-like pheromone on her that just naturally attracted to her?

Chip: This is an interesting dilemma. How do you respond to a pheromone, and what context-specific things have to be available to respond to a pheromone? As far as we know, queens' pheromones do not change as they go out and fly. The interesting thing here is that the queens are producing these pheromones that we can extract from them, and yet the drones do not respond to them in the colony, not at all. There is a context-specific response on the part of the drones. Now, if there's a context-specific response on the part of the queens, we don't know that. What you're suggesting is there might be, and there might be, but we have no way of accessing that information right now.

Becky: We were just at the North American Honeybee Expo, and I had a very excited listener come up and ask a couple of queen mating questions. I said, "You are in luck because I have got two experts. Jeff and I will be talking to them next week. I asked them to put them into an email and send them to us so that I could really get a good grasp of what they were asking. Then it turns out that we also have a hive tool from HiveIQ, a giveaway. They're slipping in under both getting their questions answered, and they're going to get a free hive tool. You don't even have to answer it correctly for them to get the free hive tool, so no pressure here.

[laughter]

Chip: That's good because we don't have any correct answers.

[laughter]

Becky: The question came from Russell Sprangle and a friend of his. One of the questions was about the mating signs when the queen gets back. They had a theory that there might be more than one mating sign left in the queen. I'm seeing a head shake no already. They were wondering because they thought that when the queen and the drone mated that the endophallus might flatten out. They were wondering if anybody's ever really looked to make sure that there's not more than one in the queen when she returns. That was the first question. I already saw a Gard shaking his head no.

Gard: Yes. When the male mounts the female from the rear, something in the female, he's stimulated by her pheromones, maybe by touch. As those stimuli are perceived, he then everts his genitalia, his endophallus, into the queen. It's explosive. You hear a pop. You hear an audible pop when this happens. He's now locked to the queen, this is locked right in there. This thing is blocking the mating orifice of the queen. Chip will know the name of the structure there, the tip of the abdomen.

Then, in most cases, when she returns to the hive, that so-called mating sign, that portion, the endophallus, it's broken off. The drone falls to the ground, and a piece of him remains in the queen. Then she returns, and you see that that's the so-called mating sign. Now, how do we know that that's probably only one at a time is from Gudrun Koeniger when she set up a revolving arm with a queen fixed on the end of it with the tip of her oviduct opened so that she could not stop males from mating with her. It was elevated up into a drone congregation area. They had a movie camera at the base of this revolving arm. As it goes around and around and around, it's basically filming a queen.

It looks like it's in place because it's focused on the queen as she goes around and around. You can see a male come up on her and then explode into her and then fall away. Then the next one comes up, and there's a certain portion of his body that sticks to that previous mating sign, pulls it out as he then everts his into her and explodes, and he mates with her. This gets repeated over and over with each male removing the mating sign and then replacing it with his own. At one time, early on, this was believed to be a blocker that this mating sign prevented any other males from mating, but obviously, that is not the case. They mate over and over and over after each one of these males' portions of his endophallus gets left in the queen's oviduct.

Chip: One aspect of this that I remember is that the males, the drones, pull the endophallus of the previous drone out with their legs. Is that correct?

Gard: Maybe it's with their legs. I can't remember which part of the body they use, but yes, they pull it out.

Chip: That's the part that I remember, but I don't remember any specific reference to that. I think that's a general assumption. They pull them out with their legs. Now, going back to another point with regard to males mating with queens. I don't think they need any extra information from the queen in order to mate. I developed an artificial vagina for queen honeybees.

Basically, I designed something that I wanted to find out what was going on with mating, at least in terms of drone behavior. I developed this artificial vagina for a queen, which was basically a harness that fitted over a real queen. Eventually, I learned that all I had to have was a tube made out of plastic that was about the length of a queen, and it was black, and it smelled like a queen, and the drones would come up and pop in it.

Becky: That was actually Russ's second question, which really did mirror what Jeff was asking. I think that you've now answered both of Russ's questions. Thank you for helping us with that HiveIQ hive tool promotion.

Gard: I'd just like to put one thing in perspective here. Colonies produce a lot of drones. They're out in the landscape. Okay, let's go and sample what's in a drone congregation area. Various people have done this, and now that we have genetic tools, you can analyze those drones that you catch in a drone congregation area, or if you want to think of it as just one point in the landscape where they all occur together, and then you can determine how many colonies they came from. It ranges from anywhere from 20 to over 200 colonies are sending these drones out there.

The point I wanted to make is there's probably 2,000 or more drones searching for a queen in the area, with one queen moving through it at that particular moment in time. Those drones have very little opportunity in their lifetime to ever mate. The vast majority of them are going to fly and fly and fly on mating flights day after day and then die and never mate. They can't really afford to be terrifically selective at that point. If they've got something that seems like a queen, looks like a queen, smells like a queen, damn, take it because that's their only choice. That's going to be it for their life. If they don't get that one, they'll probably never have another chance.

Chip: Well, that's why those mating tubes worked. [chuckles]

Gard: You get different numbers of drone-to-queen ratios, but the general estimate is it's 1,000 or more per queen, and I sum up to 2,500 drones per queen. There's a lot of drones out there for each queen at one point in space, at one point in time. Of course, she gets mated and goes home, and then another one comes out, but the ratio is still just about the same because there's so many drones.

Chip: In the life of a bee through a season, in the life of a colony, or in a life of an apiary, you're probably talking about 30,000 drones for every mating. It's an enormous number.

Becky: That is enormous.

Chip: Gard talking about the probabilities in terms of all of the drones that are produced through a season. You multiply that by the number of colonies and absolutely small number of queens that are out there. You're usually talking 30,000 to one. In terms of mating success for a drone. They have to fly fast, and they have to be good, and they have to be at the right place at the right time. The chances of doing that are pretty slim. That's why they only mate once. That's one of the other things that's really interesting here. We don't have a whole lot of organisms that only mate once, but drones do.

Gard: Very, very few that die in the act of mating. That is really rare, too.

Chip: Yes, that's another rare thing. Honeybees are pretty unique. Aerial matings, distances involved, contributions to the mating area by a lot of different sources. I think, as we talked last time, you can actually predict the common abundances of drones from different sources on the basis of the distance that they fly. In other words, we did papers where we actually had the ability to predict the ratio of drones from different colonies in space. It's a really fantastic dynamic, and it really hasn't been explored as much as it could.

One of the things that kind of broke it open, and I'm going to brag a little bit, was the fact that we developed an aerial drone trap. I think I sent you a picture of that. That drone trap is

revolutionary in terms of studying honeybee mating behavior because it allowed us to trap drones at any distance from a colony. At the same time, by knowing that drone space, we could determine where queens were actually mating.

Jeff: We're going to have to take a quick break. We'll be right back, and we'll continue our discussion with Chip and Gard. We'll transition here into the Africanized honeybee and its impact on the honeybee industry.

[music]

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Becky: Welcome back, everybody. Jeff, before we talk about the Africanized honeybee, I have just a really quick question because I know I've heard from beekeepers, especially researchers, where they're able to literally-- It might even be you, too, to observe queen mating in the apiary. If you've got the supply and demand of queens and drones, people have definitely been able to see it actually happen right at home.

I'm wondering why we talk about setting up the mating nucs in a different location than the drones that the queen breeders want to influence the mating. If you do it right, could you actually have the mating nucs within the same apiary as long as you know that the genetics are different, so you're controlling the genetics, but you have them all closer to home, and then hopefully farther away from birds and other things that could snatch them out of the air? Does that question make sense?

Chip: I think so. I can take a stab at that because I've seen what you're talking about in California. There are matings close to apiaries. The question is, is that good, or is that bad? It's bad if they're mating with their brothers. You don't want them doing that. It would not be good to have the same genetic stocks at the same place where you're getting your mating.

The question is, what's happening when you get matings close to the apiary? Are those queens actually returning from other long-distance mating flights? As they get close to the colonies where there are lots of drones, a very high concentration of drones, not necessarily in congregation areas, are they just encountering drones in such numbers that they're just mating again and again? That's a possibility that this is not intentional on the part of the queen. She just gets caught as she comes back to the colony.

The other thing would be, how do you disperse your drone sources from your queen sources? This is what we recommend. I think this is the best way to handle things. You want your queens to mate with a certain type of drone. There's a spatial recommendation for how you can do this, but there are very few places where this would actually work successfully because of the topography issues. You certainly could do that in certain areas, and we'd probably have to talk about each area and see in terms of how the drones behave in a particular area. Basically, if you want your queens to fly to the drones that you prefer to have them mate with.

Becky: You would literally set them up half a mile away or--

Chip: Probably closer to 1 mile away because the drones will fly half that distance.

Gard: In this recent review paper I published. One of the things that struck me so much is that, well, first, we don't have a lot of people who've studied this phenomenon of how far drones fly and that kind of thing. It's pretty limited. It seems that each person who's studied it or each group who's studied it gets somewhat different results because they're in different landscapes with different densities of drones and different conditions. We really have not explored that at all. We have very little understanding of what happens when you go from a low density of drones to a high density of drones.

In South Africa, there was a study by Jeff Tribe. Is that his name, Chip? At low density, when he went to trap them, they were mostly localized and trapping them in what seemed to be drone congregation areas. Then the season went on, and they got closer to swarming season. All these colonies were producing lots and lots of drones in anticipation of new queens being produced with swarming. There were so many drones in the landscape that didn't matter where he put a queen up into it, there were drones there right away to mate with it. The whole aggregation of drones into localized spots disappeared to where they were just everywhere.

Then again, we don't know how far the queens fly. If we knew that, you could see if the queen is flying out and flying a long distance. Then getting a couple matings as she came back to the home apiary, or if she's flying around right there at the home apiary mating with this mass of drones that are coming from all these different colonies. It's so complicated. We don't know very much.

Chip: One thing we do know is that drones prefer to fly downhill.

Gard: They do that, yes.

Chip: They don't like to go uphill. The drone flight is prejudiced in that they like to go down slope. You could actually predict where the flow of drones is going to be.

Becky: They have to get back, don't they? [chuckles]

Chip: They have to get back, but they're climbing their way back with low energy and so on and so forth.

Becky: Oh, that's interesting.

Jeff: Or not. They may not come back. You never know.

Chip: A lot of them don't. The average drone only lives 16 days.

Becky: Is it really that low?

Gard: Yes, it's that low.

Chip: That was Jay Cox's stuff from Illinois long ago. He did a longevity study. It seems to be a very sound study with very good representative statistics.

Jeff: Let's transition a little bit to the Africanized honeybee impact on the North American honeybee industry. When the Africanized honeybees entered the US, what changed, if anything, about the drone congregation areas? From a genetic standpoint, is it accurate to think that the Africanized honeybee took over the DCAs, or is that an oversimplification?

Gard: Again, you're assuming they're mating in DCAs. [chuckles]

Jeff: True, but DCA being the general term.

Gard: When I trapped drones in Venezuela, working with Chip way back in 1980, we had marked European, marked African drones. They flew out. We caught them both in the same aggregation areas. They weren't separated. They didn't seem to be separated in any way. You might disagree with me, Chip. I think African and European drones are flying the same way through the landscape but maybe not going the same distances.

Chip: No. Of course, they're doing the same general sort of thing, but in general, as far as we know. The really interesting thing here is, now I'm losing my thought because you distracted me. It's your fault, Gard.

[laughter]

Chip: The real impact of African bees has to do with their density, the number of colonies per square mile. That's the fundamental issue here. Not that the bees themselves are different. It's the density of the bees. The number of colonies per unit area and what we envisioned. The whole thing that got us into honeybee mating biology was the storyline that came out of Brazil. You had these big apiaries, and all of the queens from the big apiaries were mating with African drones. That set us on a course to try to figure out the dynamics of this mating process.

What we eventually realized, and we put together, and if you follow the things we've been talking about, basically, every European apiary in South America, because there are no feral bees over most of those areas, is an island. It's a genetic island, and that's just fine. They will mate with their own on those genetic islands when there are no African bees in the area. When African bees move in, they move in all around those islands. If queens are flying further than the drones from their own colonies, they're going to be mating with African drones. That's the real issue here.

That impact of African drones is therefore just density dependent. Dependent upon the number of wild colonies and the drones that they're producing and how much that's affecting the density of feral bees around these apiaries. That same sort of thing has to be going on here in the United States. The difference here in the United States

is that we have feral bees in a lot of these areas in the South. We don't have apiaries that are specifically-

Gard: Feral European bees.

Chip: They're feral European bees. That's the difference between South America and the US. We have feral European bees. Generally, they're about, in many areas, one or two colonies per square mile. That covers a lot of area. Therefore, when African bees move into an area, they are immediately competing with for space or saturating a space. They can't saturate a space the way they could in South America because there are feral European bees.

The dynamic has been different as they've been moving into the United States, and there's been more genetic transfer of European bee genes into the African population. The African population, for the very first time in this whole dynamic, is actually becoming slightly modified as it approaches this part of North America. It's becoming slightly modified. The way the data are working out, that's again a function of the density of the wild African colonies. The greatest impact they've had is areas where there are very few European colonies, both feral and wild.

Gard: As you take a tropical African bees and they start moving north into temperate areas, their ecological fitness, they're not going to be as well-matched to their environment. Whereas, we've got European bees that evolved in temperate climates, and they're really well-suited to these areas. You've got that dynamic, too, in that you're not going to have as many African and feral colonies. All of a sudden, you are going to have European feral colonies. The whole dynamic of lots of African bees in the wild and no European versus a mix of both changes the dynamic.

Chip: They're at the northern limits of this African bee phenotype. They get pushed back. They came into Oklahoma, really ripping into Oklahoma very early on in a way that I hadn't predicted. I didn't think they would get into Oklahoma in large numbers, but they got into Oklahoma and pretty much spread across maybe two-thirds of the state in low numbers. Then you had seasonal droughts, and they basically went back. The only place where there were really any significant African bees in Oklahoma is in southwestern Oklahoma. There's a small area in southwestern Oklahoma, but they haven't really moved back into mainland Oklahoma in the way they did in the first years because of the periodic droughts.

Then you get periodic winter influences as well that keep knocking it back. The effect of African bees in the US really is very density-related. That density relationship is modified by the temperature and the moisture availability and so on. They're not as cold-tolerant. They're not as drought-tolerant because they're not housed properly. Their nests are small. They don't have a lot of storage capacity.

They're in a mismatch in terms of this northern part of the environment that they're moving into or trying to move into. They're getting modified. That's interesting. That's what we predicted, but it's taken a long time. How many years are we talking about? That was a 1990 influx on the border in Texas. They're just now moving into Alabama and Mississippi, which I predicted that would happen in 1975. I wrote a paper and said they're going to move into Alabama and Mississippi. They didn't, but now they are.

Becky: You were right. It just took a while. [chuckles]

Gard: That's a big mystery to me is why they stalled out at Houston and they got established in Florida and they're moved north in Florida and slowly north. That Alabama and Mississippi just didn't seem to be places they like to be in is a mystery.

Chip: It may have been because there's a lot of wild European bees. Here's one prediction I'm proud of. I predicted that they would be in Las Vegas. That was one of the early predictions. If you look in Las Vegas, Las Vegas is isolated from every place else in that part of Nevada and Arizona. Why would you predict they go to Las Vegas? In the warm season or in the spring season, the bees could get there. Then Las Vegas itself. It's a heat island. African bees got there, and they got there earlier. They were even a part of a-- What is that famous detective program?

Becky: Is there a CSI?

Chip: CSI or whatever it was.

Becky: CSI?

Chip: Yes, CSI. They were even featured as a murder weapon in one of their episodes. [chuckles]

Jeff: Did you place that bet in Las Vegas that when they would arrive?

[laughter]

Jeff: Have you collected on [crosstalk]?

Becky: Yes. Probably could. I'm trying to think, when I've been hiking around Las Vegas, if there are warnings about Africanized honeybees.

Chip: They're still there. I think there was somebody killed there this summer.

Becky: I can't remember if I've seen a warning.

Gard: There have been some incidents over the years.

Becky: I have a question, though, because you've said it a couple of times now about the genetics of Africanized honeybees being modified. I can think of a few different ways that I'm really curious about. What are people seeing?

Chip: Well, I would have to look up the papers, but I haven't followed them in great detail in terms of what is being modified. One of the things that we established when the African bees were moving north is that all of the mitochondrial DNA in all of the feral colonies was African. One of the storylines that came out of looking at this whole dynamic was that when you got into first-generation crosses, you got really fierce bees. Colonies would build up and so on and so forth. When you got the back crosses, the next-generation crosses, everything started to fall apart. It fell apart.

The storyline there is that the mitochondrial DNA and the nuclear DNA that they would acquire from European bees did not sync well. In other words, you got bees that were less fit. You had a hybrid breakdown. That hybrid breakdown, somehow itself as a means of moving north and taking over territory and so on and so forth, has itself broken down. We don't know exactly why. Somehow, we're getting combinations now of genetic influences that we didn't see when we were working with these bees. We did not see a lot of admixture.

Essentially, the bees coming north through Mexico were very similar, almost identical to bees from South Africa when I was in South Africa. I looked at bees in South Africa, and you get something where the nuclear genome and the mitochondrial genome was essentially similar. Somehow, that is broken down. I don't know how it's broken down or why it's broken down. It's the sort of thing that you would predict.

As Europeans are more fit, as you get into situations where somehow your genetic mixes are selected to be more compatible with survival, you're going to get a modification. I don't know exactly how that's happening. Nobody's really in the field looking at these mating dynamics or looking at both the mitochondrial and nuclear DNA in the detail that probably needs to be to determine why this change is occurring.

Becky: I think it's really important to recognize the fact that we have a lot of beekeepers in the United States who are-- They're working with Africanized bees, and that's their population. Are they different than what you worked with in Venezuela?

Chip: I don't know. I don't know what they're working with. I don't know what the issues are. You get into South Central Arizona, and you're looking at bees that are not very much modified. If you look at Southern California, you're looking at bees that are much more modified. The beekeepers are looking at working with bees that are quite different from place to place. I don't know how many people are actually working with African bees. You're telling me something I don't really know. If they're really working with African bees, that's surprising to me.

Becky: I know I've given a talk to a group in Los Angeles, and they're all working with Africanized bees. I've talked to beekeepers. They'll collect swarms, and they'll go to their desert apiaries where they can safely keep them away from people and animals. They've had great success with them. I know there's a contingent of US beekeepers who've figured out how to work with Africanized bees. From what they told me is that they love it because they are not having to do a lot of varroa, if any, intervention.

Jeff: That's a whole different topic, isn't it?

Chip: Yes, that's a different topic.

Gard: It is, but it isn't because it's one of the things that changes that whole dynamic of the fitness of the bees. European bees are still heavily influenced by varroa, but African bees, for a variety of reasons, aren't affected nearly as much.

Jeff: We're only touching the surface with you two. This is really fun.

Becky: I know. Their brains are big, filled with bee knowledge. [chuckles]

Chip: We haven't really talked about swarming biology with African bees. Some of the things we've seen are just beyond the experience of anybody working with European bees.

Jeff: Can I ask you guys to come back again closer to our swarming season that we come back and have you do a whole segment on the swarming behaviors and what you want to tell us?

Gard: I think that's fine.

Becky: That would be excellent. Okay, we got a thumbs up from Gard.

Jeff: Chip, Gard, we really appreciate you taking your time today to join us and continue conversation of the drones, the misconceptions of the DCAs or drone congregation areas. We just barely touched on the Africanized honeybee impact on North America. Thank you for your time today.

Becky: Thank you both.

Chip: Great to be here with you.

Gard: You're welcome. Thanks for being here. Thank you.

Jeff: I'm always amazed after talking with Chip and Gard and still wanting to ask them more questions. I'm looking forward to our episode later this spring.

Becky: It's really good if you want somebody to come back, you just ask them, and you get it recorded. I'm glad you were able to ask them during the recording, and they couldn't say no. They're coming back because I know that every time we talk to them, they just have so much to offer. Not just us, but our listeners, right?

Jeff: Yes, absolutely. Just having had that start with the Africanized honeybees, that's when I was getting started in bees back in the mid-'80s. To hear them talk about the changes that actually came about because of the "invasion of the Africanized honeybee". It's fun to look back and say, "Well, it didn't turn out quite the way everyone feared," or, "It's changed, and it had an impact, but not the way anybody thought."

Gard: Obviously, it's still serious, but people have been so resilient as far as figuring out how to live with them and work with them, or unfortunately for the bees, but good for the protection of the people, eradicate them in just a swarm or something like that that they find in a city that's potentially not safe. It is going to be good to learn more specifically about their swarming behavior because, as a beekeeper, every time you learn about a specific behavior in honeybees, even if it's not the kind of honeybees you manage, you just take that knowledge, you apply it, and you just get a better understanding of a concept. I'm really looking forward to this next talk with them.

Jeff: That about wraps it up for this episode of Beekeeping Today. Before we go, be sure to follow us and leave us a five-star rating on Apple Podcasts or wherever you stream the show. Even better, write a quick review to help other beekeepers discover what you enjoy. You can get there directly from our website by clicking on the Reviews tab on the top of any page.

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[00:53:30] [END OF AUDIO]