I also wanted to mention that under the learn with us tab on our website. We have a resource page with lots of readings and papers and other references.
We have a lot of great references on today's section about specialist fees. So besides Brian's handout, you can see links to the special species and the central us and the eastern US and western US, and so dig a little deeper to get some details about
what's in your backyard possibly related to our specialist piece.
All right. So at this point I'm happy to turn the podium over to Brian. Brian Danforth is a professor at Cornell University, where he teaches a class that I would love to take called alien Empire.
It's for non majors and hopefully bring some new majors into the entomology department, there are Cornell or just some folks who realize how important insects are his one of his main areas of interest is the evolution of insects.
He also works a lot with pollinator biology, he's an author, maybe you see have seen his book or have a reading the solitary bees book that he co authored.
He also has a PDF publication online which is linked on our website about specialist bees and ways that you can garden to bring those special species it's focused on New York but if you're from the east, or if you just want some, some great general guidelines
about how to create those spaces for special species, and some information about their biology, you'll want to check that out.
Brian also curates the insect collection there at Cornell and he's part of the beat course which is a really fascinating program for entomologist or one a BB specialist, that brings together a small group goes out into the desert in Arizona and collects
on identifies BS.
So Brian thanks so much for being with us this morning I'm excited to learn more about special species it's one of my favorite groups. Appreciate your time.
Thank you, Denise, I'm going to share my screen now is that ok.
Okay, um, thanks very much Denise for inviting me.
This is a, this is a new talk.
And I, I found this opportunity to really dig into the kind of literature and biology of specialist Bs, just a great opportunity to kind of revisit some of the literature on this subject.
So the good news is that I'm, I'm very excited about this topic. The only downside I can think of is that I've actually never given this talk before. And
it's the first time we're going to try this out so.
All right, so, um, I've decided to cover a number of topics about specialist fees.
Some of them in more detail than others.
I'd like to introduce you to some of my favorite specialist bees to start out with.
I'd like to end in a suggest that many of the specialist bees are of conservation concerns so when we are looking for groups of organisms to focus on for conservation specialists, especially within the bees are really an important group and I'll show
you some of the literature that supports that will talk a little bit about the the the terminology we use to describe specialization and B's,
including all the collective Polly like the Nisa lucky those kinds of terms will look at how specialization is distributed across be phylogenetic, we'll look at how specialization is distributed across habitats.
Well, we'll take a quick detour into whether or not specialization is an ancestral or a derived trait within these will explore a little bit about the host plant families that be specialized upon will talk about the implications of postponing specialization
for evolution, both in terms of rapid evolution and diversification.
We'll talk about some experiments to uncover why these specialized at all.
It's a bit of a puzzle why any organism would specialize on a certain limited resource. In the case of bees they specialize on a single plant genus or, or family and so you have to ask yourself, why, why would they choose to do that when they could be
using all the floral resources available in the, in the area.
And then finally, I want to talk about how you can conserve specialists in your backyard.
For primarily in the eastern United States.
Alright. So just a quick run through of some of my favorite specialist bees.
To give you a sense of what we mean by a host plant specialist.
One of my favorites is Desi po to Argentina, this is a European Vu find this on in beaches and Sandy areas in France, and Mediterranean Europe, its sole host clan is scabby OSA in the family Gypsy Casey, and you will not find this be unless you find its
host plan
in the family collected a real fighters is one of my favorites. This is a fascinating small black be that lives again in, in, in Europe and and North Africa.
They are specialists on the genus Stacie send the family lady AC.
And they have specialized hairs on their face, so that when they enter the flower and vibrate their flight muscles, the pollen adheres to their face, and they then groom it off and bring it back to their nest.
So not only do they have a behavioral preference for this particular host plant. They also have morphological adaptations for harvesting this particular host plant pollen.
And that's true of most specialist bees. We are not just talking about a behavioral specialization here. We're talking about a whole suite of traits including morphological specializations going along with certain affinities for for particular houseplants
in southern Africa where some of the most fascinating these live.
One of my favorite specialist is the genius by Delia, these are kind of like dinosaur bees.
They are an ancient group they're at least 100 million years old. And we know that because the South African lineages have relatives in South America.
So we know that South American South Africa split about 100 million years ago. So this relational lineages of lineage of BS reflects that split in the southern hemisphere.
And in South Africa, there's a group of be used in the genius by Delia, they're all host plant specialist, and they are ground nesters.
And this one in particular if ideally of Llosa is one that I've collected on museum Bry anthem. And again, this is the that you will only collect if you find this particular host play
in South South America.
This is one of my favorite bees I've never actually collected it but it's a beautiful and odd looking be, this is chilly Melissa Rosen I in the family commodity that's a specialist on Ilana, which is in the family so an AC these bees have elongate mouth
parts, and a greatly elongated head for reaching the floral neck surgeries at the bottom of that of that flower.
So again, morphological adaptations to host plant specialization
in New York, we can find a local specialist be one of my favorites is met crocus new to this is an oil, be it requires it lives in human habitats along streams and rivers, and it requires access to its floral host Lissa makki a silly yada.
And it requires these floral oils to line it's brewed sales and also to prevent it provision it's brewed sales, it's um it's provision. So, this is a specialist.
One of the approximately 20% of New York species that are host plants specialist.
Alright, so why should we care about houseplants specialist. There's a lot of evidence that host plant specialists are in fact among the most threatened, all the species, and I'll go back to a paper for 2006 by these Meyer at all, where they they showed
that surveys of, of being hover fly assemblages and Britain and the Netherlands found that, depending on the assemblage and location pollinator to clients were most frequent and habitat and flower specialist.
driving home the point that these are really the ones we should be worried about when we're concerned about conserving native the species. In a recent paper and 2020 by a group in Czechoslovakia Bogo shuttle found that all electric these are proportionally
more strongly represented than Polly electric these among the Red List red listed species of the Czech Republic.
And most of these red listed. These are risk restricted to particular habitats and particular host plan so again.
In Europe, we find that the specialist bees are the ones that we should be most concerned about.
In North America, Laura Burkle and her.
Her group study bees in in the Midwest, and they repeated surveys done by Roberts back in the, in the late 19th century.
And they found that the loss of bees in that region was non random such that these that were specialists, or parasites or cavity Nestor is where the most likely to be extirpated relative to the surveys conducted by Roberts' in the 19th century so again
specialists, were more likely to be threatened than generalists based on Laura Merkel's work.
So all of those papers suggest that we should be concerned about houseplants specialists so let's, let's dive into the literature on host plant specialists and and and the terminology that we use to talk about host planet specialist.
And I take these terms from a paper by Kanan sites from a book chapter published in 2000, and they divided say sort of grouped bees into various categories, and depending on how narrowly their host plant specialists were restricted so for example a mono
electric be would be restricted to a single plant species, a narrow all electric be would be restricted to a single plan genus all the Galactic these would restricted to clan general within the same family.
And then on to more broadly Polly lactic species.
And then a term they coined which I love, which is called a collective collective, which means bees that are restricted to a small group of unrelated host plant families.
And one example of this is Azmi arriva Flores, amazing be that visit, primarily three plant families, but they're totally unrelated to each other, and their flowers are different in morphology so you do find these kind of oddball cases of eclectic all
collected.
Now I don't want to burden you with too many terms.
But I, and I actually think it's better to think about host plant specialization and bees, as a kind of continuum.
So if we think about it that way we can go all the way from narrow host plant specialist down here on the left, including one of my favorite bees has purpose or area, which is mode electric in the on the along the coast of Florida, and the Gulf states
in the US to a very generalist, the apex belief or the honeybee, which will visit hundreds and hundreds of plant families for its pollen and vector.
So don't get bogged down in the terminology. Consider this really a range of host plant preferences, and we're really today going to focus on the left hand edge of the, of the spectrum, the BS that tend to restrict their floral visits and their, and their
pollen collecting to a small group of related plant families.
Alright so let's, let's take a look across be phylogenetic and ask where do we find the specialist bees. And this will give you a sense of, of how widespread specialization is.
So this is a philosophy of the families there are only 70 families from validity to the, to the family community, and we'll dive into each one of these families, and we'll see that within each family.
There are lineages that are largely host plants specific
within validity. This is one of my favorite groups. This is a relatively small group of bees.
About 200 species, but virtually every species in this family is a host plant specialist. So you have houseplants specialists on the family borage and AC on oil collecting plants like list of Makkah, and on plants in the family's Aster AC so the the composites
and their relatives.
And these figures just show you the relative numbers of species, or the total number of species within each of the sub families within this family. But for this family at least they were really all host planet specialists and that's the earliest branch
of before
moving on to other families like a pod.
We do see that there are a number of fit some families have a party. If we wanted to identify the sub family with the most narrow host plan specialist, it would be this one, the sub family used to writing.
This includes many host plan specialists, including these that are restricted to mellows asters, and many other particular many other families of of flowering plants.
This group are brood parasites and the other groups tend to be rather generalized in their floral visitation.
In the family mega ecology host plant specialization is also widespread. So within this Bazell lineage of ideally ions they're all host plant specialists.
However, oftentimes are thought to be host plant specialist Luther joins or largely host plant specialist on plants that produce large pollen grades for example, mellows cactuses.
And those kinds of plants, courbet's as well. And then within mega Kalina we have a number of hosts plant specialist as well. So host plant specialists specialization is widespread within the mega quality.
In the identity, we have to some families which are largely houseplants specialists, Andhra 90, which includes the large genus and Rena. And then there's some family Penner Jayanti These are things like PR to Kelly obvious macro to groups of, of, of particular
Within the collectivity we typically think of collectives as being rather broad Polly lactic be so they don't tend to be very highly specialized, but that's because most of most elected bees are in this so family the Holic tiny, those are that's the group
that would include things like Lazio blossom colitis.
But remember there are other sub families of liquids. No mines are largely cosplay specialists. And so our role for times the Bazell lineages of collectives are often very narrow host plant specialists.
Within community we find host planet specialization scattered throughout this group of South American largely South American and African groups, and Australia groups are largely houseplants specialist.
These are host plant specialists, call a tiny including the genius qualities or host plant specialists, and then you have more broad associations in this group here.
So again, the take home message here is that specialization is is widespread across the the families, there is no be family that doesn't have specialists.
And it's a particularly common in the family validity.
Alright so now I want to turn to geographic
specialization. So I'd like to ask the audience and we have a poll that we're going to conduct.
Where on earth would you expect to find the greatest proportion of specialist bees. and I've given you a few choices, deserts. Great Plains, Eastern deciduous forests, or tundra.
And I see that people are responding actively to our survey. And I'll give you a few a few seconds to continue.
When the response rate kind of dies down. So this is something that is important to think about when you're thinking about where you want to go collecting these for example if you wanted to study bees and you wanted to study specialist bees in particular.
You know what geographic region of the world would you go to.
It looks like people have very strong opinions about this, which is great.
I think deserts in the Great Plains or close a race to
to win this, this poll.
Great Brian and we have so many people voting in that while we have a second. I wonder if you could just say what red listed bees are because I'm sure there were questions about that.
Oh, right. So a red list would be would be abundance of of high conservation concern so it's a B that's considered to be threatened or endangered in any part of the world.
So I think the poll looks like it's wrapping up here, Denise.
Do you want to end that so this is great so thank you for responding.
32% of the people consider deserts, to be the place where you would find the most specialist bees, an equal number of people felt that the Great Plains were a place to find specialist bees.
The Easter deciduous forests 28% people. And, and for tundra 9% of people. And I think you're absolutely right, the tundra is the least likely place to find a high proportion of specialist bees, but I'm going to move on to the next slide and show you
results from an empirical, should I share results Denise.
Sure, go ahead. I tried to do that but yes, maybe that's something I have to do.
Um. Now I'm going to close the poll I think because I don't want to stop sharing. Okay, there we go.
Alright, so thank you for your for your responses. Let's, let's just look now at the what the what the literature would suggest about this.
Oh.
Oh, there we go.
But what he did was survey, the proportion of the species that are specialists across various habitats in North America.
And what you can see is that in desert habitats and Mediterranean climate regions, you have more than 50% of the species, being specialist. So the answer to my question was, the true at the correct answer is desert.
The correct answer is deserts. There are many specialists in the Great Plains, there are as many as 35 to nearly 40, but really the peak of specialization is in the desert regions where, where flowering occurs in very brief period of time, and there is
an enormous number of flowering plants blooming simultaneously.
So we really should repeat this this survey it's getting a little old now, but I think this is, this is a result that will be held up, no matter how we look at the at the results.
So, if one were to go, collecting these in North America, where would you go, well I luckily we have a recent study by Michael Oren colleagues, analyzing species richness patterns across really across the world but this is the figure from their paper
on North America. And what we showed here is in color from low species richness and yellow to high species richness in in brown and dark red. And what you can see is that in the, in the desert southwest here, the western United States, we really find
an extraordinarily high species richness and that's associated with this increase in specialist bees, as well. So that's where you would go to find the specialist.
It's also where we find the greatest species richness.
So if my wife is listening.
I would just like to remind her that when I die, I would like my ashes spread in this part of the world.
Alright so let's move on. So
one question that I'd like to ask is, which came first specialization or generalization. And this is a question we can answer with phylogenetic studies and I picked one study by Claudia set of he and colleagues in Switzerland.
And what they did is they constructed a philosophy for the genus hope lightest, which is a mega Kylie be.
These are stem nesters.
And not only did they construct the phylogenetic they analyzed the pollen loads of all the species within this phylogenetic, and they characterize those these as to whether or not they were a specialist or a generalist.
And they even characterized what their host plant specialist group was so for example, these lineages and purple include these that are specialized on board Echinacea.
Now the generalists are showing up here in red.
And what you can see from this tree is that the ancestor of hope lightest was probably a specialist on borage and AC, so that that would be things like MGM would be a typical host plant for these bees.
And as you progress, up through the phylogenetic you have switches to other host plants, but it's really not until you get quite far up in the phylogenetic where you, you see a generalization evolving.
Now, this pattern of generalists arising from specialists, is something we see in other host plant specialist bees.
And so this is a, not this is not only restricted to this particular study it's actually a quite a common results so specialization may actually be an ancestral trade and B's.
And what we find is that from that narrow host plant specialization you do get lineages that then radiate out to a more broad poly lactic kind of behavior.
Now I want to switch to another topic I want to ask the audience to think a little bit about where you would expect.
The host plant specialists to land on a philosophy of the angiosperms family so this is a figure taken from the Missouri Botanical Gardens website which I love.
This is one of the reliable sources for understanding the phylogenetic relationships among angiosperms plants, and this is a phylogenetic the ordinary level.
So orders include multiple families. And these are for the you daikon so that represents 75% of all flowering plants. So we've left off the mana cots and some other lineages here because they're not they're not as frequently visited by bees and the cards
are really the group that includes primarily the host plants of of most specialist bees.
And don't be daunted by this figure you probably can recognize some of the names here. Asteroids would include the SJC, the Astros and their relatives.
Here's Rosalie's which includes rosacea he and other lineages that your host, hopefully familiar with. So I want to ask you to think a little bit about if we were to map on host plan associations for specialist bees onto this phylogenetic.
Where would we expect those associations to land, would we expect specialist these to be restricted to one part of this phylogenetic, or would we expect them to be more broadly distributed across all the philosophy of the angiosperms.
Now remember that you die cards arose over 200 million years ago, and we think many of these specialists be lineages arose much more recently.
Alright so let's take a look at, at,
what we find. So, within the family validity, these are general of validity is across the top here.
And I've picked a few of the ones that that for which we have good host plant data. And what I want you to notice is that each of these general is distributed widely across the philosophy of the angiosperms.
So what that suggests is that these bees are really not constrained Fila genetically by their by their hosts there, they're jumping around in the philosophy of angiosperms quite a lot.
And there's quite a lot of host planets switching going on within each of these lineages.
If we take a look at specialist bees within the Trinity. We see the same thing. If we look at and Rena which is a relatively recent group, only about 20 million years old, or per teeny another group that's very recent about 20 million years old, we can
see that they've, they've colonized virtually all orders of angiosperms plans, so they've radiated onto the angiosperms in a sense, rather than being restricted to certain angiosperms plates.
Finally, if we look at mega pilots we see a slightly more restricted tendency these groups tend to be restricted to the steroids. But of course they are scattered across the entire philosophy of the attributes firms.
So again, what this tells us is that host plant specialist species are restricted to certain host plant, families, but within those lineages, they're able to jump across the phylogenetic angiosperms in quite an amazing way.
All right, I now want to turn to a topic about sort of how rapidly houseplants specialist specialization can evolve. And I want to talk about one example of a flowering plant that that's familiar to be biologists in the desert southwest, this is Larry
I tried to Tata. The creosote bush.
This is a plant that is now the dominant shrub in the center in Shaolin and Great Basin, and Mojave Desert.
But this is a plant that arrived in North America fairly recently so this is a plant that we believe arrived from South America from relatives in South America.
Just somewhere between 500 that 500,001.5 million years ago.
So in the great scheme of terrestrial evolution, really in a very recent period of time This plant has arrived and has completely dominated the desert southwest.
within that short period of time, just 1.5 billion years. There are 19 specialist bees, which have adapted to utilizing exclusively Larry as a pilot source.
And these specialist bees range across many families and Trinity community, add validity and mega Coyote.
And none of these specialists BS in North America have close relatives that are Larry a specialist in South America. So, these are de novo specialists that have arisen in along with the arrival of Larry a trident Tata into the desert southwest so that's
quite fascinating it means that these colonize a floral resource when it arrives.
Very, very quickly.
So again, emphasizing this idea that host plants specialization and bees is a label trait, and one that evolves very rapidly.
I want to just say one other study this is a recent phylogenetic study by siloed sponsored.
That looks at diversification rates and fees. So what he did is he looked at the rate of diversification for many different lineages of bees across the phylogenetic.
He looked at the the stem age, which is the age of the common ancestor of that lineage, and then the crown age, which is the, the age of the most of the modern relatives within that lineage.
So, these two ages are correlated with each other.
And as you go to the upper right hand corner of this graph is where you find the species and lineages that are diversifying most rapidly.
And I just want to point out that there are two major host plant specialist lineages that are up here in the rapidly evolving lineages of of these.
So host plants specialization itself may actually make these lineages prone to wrap it diversification.
So now let's step back for a second and ask, why would be specialized at all.
Why would specialization being adaptive trade for these bees.
And what advantages might host plant specialists have over host plant generalist.
So, there are many hypotheses and they're not mutually exclusive, but I want to walk you through five of those hypotheses. This is hypothesis one that specialists are more efficient foragers, and this is in fact supported by work by Karen Strickler in
the 1970s, where she compared foraging efficiency of a host plant specialist to quietest have the employees with foraging efficiency of other species in the same area that are more generalized, and what she found was that her measure of efficiency puts
Hulk of societies ethic employees out here well beyond the range of these of these generalist visitors. So this B is just more efficient and extracting pollen from its host plan.
And therefore, It has an advantage over the generalist foragers
Now another hypothesis is that the specialist bees are choosing host plants that have the greatest nutritional value.
So maybe that explains why specialists are doing so well. They outcompete there generalist relatives, because they're essentially using the most valuable floral resources out there.
And this was a question that was examined by Ty Ralston Jim Cain and Steve Buckman in a classic paper published in 2000 where they analyzed protein content across be visited flowering plant families.
And what they found is that there is in fact no evidence that specialist bees are particularly focused on nutrient rich or protein rich pollens over pollens that are less nutritional value so it doesn't appear that the specialist or necessarily reaping
the the floral rewards that are most rewarding.
In the environment.
Now another hypothesis is specialist bees are using super abundant resources. Now if you look at the post plant families that specialist, please visit, we find that there are a lot of specialists on malaria for example in the desert southwest.
There are a lot of specialists on very common Aster species like Healy and this.
There are a lot of specialists on sailings, which is a, a flowering Willow in the eastern US which provides a massive amount of floral reward early in the spring.
And it does seem that this is a plausible hypothesis that these super abundant resources are magnets for host plant specialist bees.
So that's one possible hypothesis.
Now another hypothesis is that these are specialist bees are able to synchronize their emergence and activity with their host plants more effectively than generalist fees, and for this I refer to a study by Bob mainly from 2013.
This is a fascinating study of a bee fauna in the desert southwest This is a study that was done on the Arizona border with Mexico.
And Bob studied the photo of the San Bernardino reserve over three years. So we have years.
2005 did that should be 2006 2007.
And what he did is he looked at the abundance of bees on mesquite, and the abundance of these on creosote bush over those three years.
And he divided those bees into specialists and generalists.
And he found for example that in the first year, there were equal numbers of specialists in generalists on the ski.
And they were equal number of specialists and generalists on creosote Bush, so that's been a good year.
In this next year we had a drought, so there was very few flowering plants came into blue mesquite did bloom, because mosquito has deep tap roots creosote bush did not blue.
And what Bob found was that the specialists on creosote Bush, shown here by this little bar chosen not to emerge in this drought year.
So these bees were able to tell that this was not a good year for their host plan, and therefore they chose not to emerge on that year, which is a brilliant adaptation to living in an in an unpredictable environment where rainfall
can sometimes be absent and your host plants may not blew it all.
In the following year. The generalist then came out again, both on the skied and on creosote Bush, as well as the specialist, and in fact a specialist had a particularly good year in that, in that post drought year.
So what this tells you what this is the specialists are synchronized with their host plants. When the host plants are having a bad year, the specialist stay in the ground, and choose not to emerge, which is a wonderful illustration of their ability to
track their host plan phonology
another, Another supporting bit of evidence for this hypothesis that specialist bees are in temporal synchrony with their host plants again comes from work by Bob monthly and colleagues.
This was worked on, on the creosote bush bees of the desert southwest.
And they studied for of the desert regions Mojave lower and upper storage alone.
And these deserts are arranged in in from low rainfall to hire grateful.
And what these what Bob Marley and his colleagues discovered was that in the lowest rainfall deserts of North America.
You have the highest proportion of specialist individuals and specialist species.
So specialist dominate in these dry unpredictable arid regions. And it's possibly because they're able to synchronize their emergence with their host plants.
This study parallels the earlier study I talked about by mole donkey, again, suggesting that deserts are the place places where specialist bees are the most adapted and the most diverse.
Now, another hypothesis is that specialist bees have overcome plan to fences and have left their generalist behind.
And this is certainly a hypothesis that I believe makes sense. Many of the host plant special host plants that specialist these visit are fairly toxic, we know for example that Aster pollen has high levels of of toxins we know for example that members
of the family for Echinacea like xem are fairly highly toxic pollens to generalist fees.
So we think that these specialists have overcome some of those plant defenses and that has facilitated the radiation onto these very abundant resources.
Now one of my favorite examples is, is this be entering a straggly study by Jim Cain, which visits a highly toxic host plant called def cameras. Now this plant can kill foraging forging animals.
It can kill a foraging mammals like goats and cattle, and yet there is a specialist be that makes its living exclusively collecting the pollen of this particular host plan.
So, that suggests that these bees do have the ability to overcome these plant toxins.
Now a final hypothesis I want to just mention, which I think is so fascinating is by Dakota sphere and colleagues.
And what they found was that these that specialize on certain what we would consider it to be rarely unpacked relatively unpalatable host plants in the family Esther AC have lower parasitism rates than those that specialize on other plant families, or
that are generalists.
They did this study in Colorado, using stem nesting bees and the genus asthma.
And when they grew up their species into three categories.
What they found is that the Astro specialists were the least had the lowest levels of parasitism.
So these black bars indicate on Paris antis brewed sales white bars indicate Paris antis brewed sales. Notice that the fab AC specialist and the generalist always have some level of parasitism.
But in the Astor AC specialist in across the four years that they examined there parasitism rate was zero at the sites where they were studying.
So it could be that these.
These are benefiting it by essentially self medicating against against parasites.
Okay, so let's move to to the topic of conserving specialists in your backyard, we've established that specialists are rare and certainly of conservation concern, we've done, we've taken a deep dive into the biology of specialists.
Now let's, let's take it back home and look at what we can do as individual homeowners or individual landowners to preserve specialists and I'll, I'll take the New York be phone.
As an example, This is what I'm very familiar with.
This is a summary of the general that we have in New York arranged by family and their relative number and the number of species within each of these general.
If we ask Okay Where do the specialists occur within this across these genera, it turns out about 20% of the bees of New York are specialists, and that would be typical of the eastern US, in the eastern US about 20% of the phone would be specialists,
if you go out to the desert southwest, you're looking at more than 60% of the phone of the specialists.
And yet, we do have a diverse array of specialists, even in New York, even in the eastern US, we have specialists across all of our plant, all of our be families and treaded specialists abid specialists completed specialists collected specialists mega
pilots and of course Melinda's.
Now I'll highlight a few of these specialist bees that I'm familiar with mela Sony's Drury Alice is a late summer solo Daigo specialist that we find in large numbers around here we can find the nesting and large aggregations.
This is a fantastic be, again it's it's restricting its floral resources to just a couple of closely related general within the Ester AC euphoria minority is another host plant specialist.
This is a small black be that's restricted to minority
Tila three expand before this this is the specialist that, well, Denise mentioned at the introduction.
This is a specialist on hibiscus, you will find this be in backyard gardens, where hibiscus is is present, and in New York, this is a relatively rare be but as you move south, it becomes a much more common be
in New York, we have a specialist couple of specialists comedians comedians Validus is one that's a specialist on a, on, Eric Casey. And this is a fantastic deal with a long face that specialized for reaching into the narrow opening of the, of the blueberry
or effects idiom flower
khalidi slide of Tarsus is another host plant specialist This is one that's on the genius faceless and in the family solid AC, which I've actually really very high protein content Paul and so this be is making a very good choice this this B is feeding
on Paul and that's got the protein content of of a hamburger.
And that of course in the, in the early spring we have a beautiful early spring and Trina Trina originally, Eric ne which visits spring beauty clay Tonia virginica in the eastern US.
Now, those are all those are just a sampling of some of the specialist bees in New York.
But we wanted to give gardeners in New York, some guidance on how to
plant guard plant gardens that would be most beneficial to the, to the 20% of New York these that are host plant specialists and so I'm Maria Van Dyken my lab, along with Christine boys Rosemary Parker and Bob Wesley at the Cornell Botanical Gardens developed
a pollinator garden booklet. This is available
through the OSU website it's also available through the Cornell pollinator Network website. And this is a got a booklet that will help a backyard naturalists or a master gardener, develop a gardener, a garden in the eastern US, that will be particularly
beneficial to the specialist. One of the things we noticed with some of the other gardening documents that we looked at some of the ones on published by Xerxes which are excellent.
They tend to focus on floral resources for generalist beads.
And we wanted to produce provide a little guidance to people who want to preserve or specialist pollinators. We want to give a shout out to Gerald Fowler who provided us with an incredible resource his, his database on specialist bees, initially was produced
just for the eastern US. Now he has
document for the Midwest as well as the, the western United States. And so, Big thanks to Jared for putting the data set out there and making it available to us, and it's from Jerry's data set that we built our pollinator garden.
Manual.
I'm going to wrap things up here, I want to make a special acknowledgments to Maria Van Dyck who took the lead on developing our pollinator garden document.
Who put the whole document together and and produced a beautiful resource for backyard naturalists in the eastern United States.
I want to thank the members of my lab to all contribute in various ways to the research we do on solitary specialist bees around the world.
big shout out to my family who have always been very supportive of my fascination with these.
I'm a little plug for the, the, our book on the solitary bees published in 2019, there's a link on on the OSU website. If you'd like to learn more about the book.
We do have a chapter on specialist BS in the book.
And finally, I'm very happy to answer questions via the chat
from anyone who has any questions about the material we've covered so far today. So thank you very much.
Denise I'm going to turn it back over to you.
Okay, fabulous Thank you, Brian I think you scared, some people with your charts but you brought us back and talked about plants and showed us some of those fascinating bees, in fact one of my favorite bees which is the spring beauty mining be, and the
question that came to the very top of a q amp a panel. So again, folks, be sure to put your, you can put questions in the chat I think they're going to get lost, we can share that with Brian, but we're working with the q amp a box for questions.
The question with the most votes was from Joe who asked how important those spring emeralds are for these other pollinators and specifically those specialists.
So in the.
I think I in the eastern US, where we have, we do have those that early spring flowering of understory a femoral, as well as the the canopy of the forest, the understory ephemeral is a really where you have the specialist BS.
So that's where I think you'll find that the highest level of houseplants specialization.
But we're actually really discovering just now thanks to work by
a by my, my graduate student.
Cast urban need that the flowering forest canopy is actually a resource, not only for specialists, but also for generalists So, I'd say both the understory and the flowering canopy are both valuable resources.
Okay, thanks. Can you take just a minute and talk about how cast is gathering her be data from the canopy is just so fascinating.
Yeah. Cast has moved on to a position at Xerxes now so I hope that you'll all interact with her through her role as a, as a pollinator consultant with Xerxes cast his background is in tree climbing.
She has a, she has a background in forestry, she loves climbing trees so part of her PhD involves climbing oak trees and maple trees in eastern in, in, in New York State setting out pan traps and capturing these in the forest canopy.
To understand how how those forest canopy flowers are a resource for native bees.
I just think it's so fascinating I am so intrigued by be researchers and the questions that you come up with and then the strategies you developed to answer those questions.
It's really amazing.
I'm there couple questions Brian about how how these specialists bee's nest so few folks are asking will be hotels, how or Tom says has his garden has really heavy clay soil, any hope that those specialist might ness there so what are the nesting habitats
in general. Yeah, one thing I didn't point out I think at the beginning was that all of the bees we've been talking about all of the specialist bees are solitary, so you don't find any social bees that are highly host planet specific, and that makes sense
because social bees are active over a long period of time they have to be able to forage in the, in the spring the mid summer in the late, you know, in the in the fall, so we don't find specialization in the social bees, we only find it in the solitary
bees, and many of those solitary bees are ground nesting, so I would say the majority of them are ground nesting. There are many stem nesting solitary bees and many of those are our host plant specialist.
The genius who applied his colostomy they will go to trap nest.
The question of how to enhance the ground nesting population of these in your backyard is a challenging one because it's really not that easy to modify the soil texture in your backyard.
But what I could. What I could recommend is that you simply fill up the soil, loosen it in certain areas of the of the of the yard.
If you are particularly enthusiastic.
Make sense of sand, so make the soil a little bit better drained, so that it's it's softer, more malleable and easier for those ground nesting bees to dig in.
But it is hard to predict what particular soils ground nesting bees are going to choose.
I just think the best thing you can do is probably to to dig it up and not make it too compact.
Okay. There was a question from a participant from Ohio Who says I have, I have some of the same plants native to me here in Ohio that you have a New York, can I expect to have the same specialist beads.
Yes, yeah. Most of the bees that we covered in our manual are not restricted to New York, they are widespread across the eastern US some of them into the Midwest.
So now our pollinator guide should be quite good for you know much of the eastern US, maybe, maybe across into the Midwest I think you, you, you, you would you would find that the species we've listed there will also be present.
You might also consult the Xerxes society website because they do have
a flowering plant lists by region. So, those flowering plant lists are modified and adjusted by different geographic regions.
But again, those are going to be lists that are largely for generalist views.
So Nancy is from New York and she wants to know what wildflower seeds can I so right now and wintry New York, and maybe the region. More broadly, that will help these special species any favorites that you can think of.
Um, Oh boy. So here's, here's a.
I just have, I have to admit that I'm not a terribly good gardener so i would i would consult our pollinator guide.
And certainly if you'd like you can reach out to the, to the people at the Cornell Botanic Gardens, they actually make native seeds available to people, they have a native seat back, which they would be happy to share with interested gardeners, and they
would have some good recommendations for what plants could be planted at this time of year versus later in the, in the spring.
I think some of the plants that we identify in the guide are already native to our area so obviously things like sola Diego
is golden road is very common and easy to attain and that would be one to, to encourage in your backyard flowering trees are also good so early spring flowering trees in the family rosacea.
If you can buy a crab apple or, or put out a cherry or, or a pear tree, you're going to be doing great things for the early spring bees.
Not a calorie pair folks but a fruit fruiting pair but yeah, apples, one of the really best plants and Brian I think you were part of that study at Cornell that looked at and you have that wonderful publication that shows what is it something like 137
different species of be that that came to apple trees and orchards in New York. Yeah portraits are a great resource for peace in New York, especially in the early spring.
And that will orchards will attract many oz Mia and Rena lazier blossom.
Lots of bees will visit those early spring flowering trees.
Okay, and I'll add that I don't think I have a specific link to that Cornell orchard publication on our website but I'll add that in just a few perennials that come to mind here for us in Ohio.
So for those of you who love the, the seeds. I think of asters and iron leads both rich with specialist BS. And if you go to those Draghi and Fowler guides so we have those linked on our reading page, and they often list which plants are the best which
families are best or which groups are best so plants as Brian said in the Astor family in the blueberry group in the Rose family's you're going to be able to find regionally which which plants tend to be most favorite by most favorite by special species.
And I know Brian You said you weren't a gardener so you can pass on this question if you want but since we were talking about something like golden rod sola Diego and participants may be thinking you know I'm not going to plant a golden rod in my garden,
but there are some nice cultivars cultivated varieties or some people say native ours of golden rod. Do you have an opinion on their usefulness to specialist bees.
I think I'm going to defer to my botanical experts co authors on the guide, they, they, they seem to have a very strong opinion about Native versus non native plants, and they prefer the native, if possible, rather than the.
The cultivated for you, rather than the.
The domesticated variety. So, if possible. I think the the wildest versions, you can find would be the best. Okay, good.
Um How about items that are applied to plant So Dan has a question about deer and rabbit repellents does it affect insects that are feeding on those plants, and someone else asked asked about soil chemicals fertilizers that we may use to those have an
effect on on some of these bees. That's a great question and I don't think we really know to be honest, certainly, certainly insecticides or not a good thing.
We also know that fungicides are not a great thing for most solitary or most of these. I don't know about fertilizers, or,
or a deer repellents, I, that's a great question.
And so, plants that are going to have rich nectar source, or do these specialist bees go to different plants for nectar so people were asking, well what do they feed on when they're host plants isn't in bloom.
Oh, right. So that's one of the things I, I should emphasize is that many of these bees are synchronized with their particular host plan. So for example, let's take the solar Daigo specialists.
They only emerged in the late summer when sola Diego was in full bloom.
The rest of the year they're overwintering as larvae underground or in a stem somewhere.
So, they don't really have to identify alternative floral resources when they're flower is not in bloom.
I will say that they are most of the specialist bees were talking about our pollen specialists. So we tend to think of specialization as, as, really focused on sort of pollen rewards, which are the most valuable to most solitary these those are the protein
source for their offspring. Many of the specialist bees will nectar on a variety of those plants so nectar resources don't seem to be particularly limited for a lot of these bees.
It's really the pollen resources that are of particular concern for for these specialists.
Our last question can you take a look in your crystal ball and give us your thoughts on climate change and these bees and whether we may see some uncoupling of plants and bees What are your thoughts on concerns with climate change.
Yeah, that's a great question, um, there, there is only now a little, there are a few groups that are starting to investigate this I mean that is really the issue on what's going to happen as flowering shifts earlier in earlier in the season, or the bees
going to be able to keep up with that.
We have some evidence from studies in the northeast work by Nacho Bartow as out of Ray Winfrey's lab that suggests that the before of the eastern US is actually shifting earlier and earlier, they're tracking the earlier and earlier flowering of their
host plant.
Their their host plans. That's good news, I suppose, they're able to track the shifting phonology. I'm much more concerned about places like the arid regions of the desert southwest, where flowering is already unpredictable.
If we make it more unpredictable.
It becomes even harder for those host plans specialist to track their host plans so I think that's the big unknown what happens when rainfall patterns in the arid regions of the world where the specialists are really most diverse, or disrupted or where
the drought periods get prolonged.
You know the reason that those specialist bees can survive in those arid regions, is that they can time their emergence to the flowering of their host plants.
Now if that flowering occurs every three years.
And they can overwinter for three years, that's great.
But if that flowering then gets proposed prolong to five years.
We don't know if those bees can overwinter for five years. It really is their physiological limitations to what they can do.
So, I am particularly concerned about what the the deserts are going to be like as climate change accelerates kind of the drought work, well you know, makes the drought periods longer, and therefore harder to predict for the specialist fees.
That is a great question and one that I don't think we have an answer to.
Thank you.
Thanks to everyone for coming this morning for this session I want to encourage you to investigate special species in your region and find some of those plants that are important to your, your particular neck of the woods.
Sam Draghi who was a wonderful be biologist talks about, there's an ironweed specialist be a Longhorn be I mean he talks about that be only needing seven little tiny flowers on ironweed to collect enough pollen to provision one cell for an offspring so
you don't need a pasture of ironweed you don't need even a big sweep of plants, just a few plants really makes a difference. So again, Brian, thank you so much for sharing your expertise and your time with us thanks for your great guide their free on