Founders of the Feast

In this special holiday edition, Lisa and Pam explore the untold stories of the true ‘founders of the feast’--the pollinators who make our festive table possible. Dr. Margarita Lopez-Uribe shares her expertise on a very important specialist  bee, and cranberries and dairy products get a look-in as well. So if you’d like some fascinating, non-controversial conversation starters for your holiday gathering, tune in!

Resources:
http://www.snetsingerbutterflygarden.org/activities.html
https://lopezuribelab.com/squash-bee-biology/

Transcript

Pollinators and Thanksgiving Foods

Lisa 0:06

Hello everyone and welcome to Pollinator Confidential , a podcast featuring the untold stories of native plants and the pollinators who love them .

Pam 0:17

I'm Lisa Schneider and I'm Pam Ford , and we are Penn State Extension Master Gardeners from the Snetsinger Butterfly Garden Habitat Project , located in Tootick Park in State College PA .

Lisa 0:32

Well , Pam , it's getting to be that time of year . The holidays are just around the corner and , if you're like us listeners , thanksgiving is about one thing .

Pam 0:44

Food , Well food and family of course .

Lisa 0:48

So today we're going to take a closer look at the true founders of the feast Pollinators , because without pollinators , our traditional Thanksgiving table wouldn't look the same at all . Now you might have heard a statistic that's often given that up to one-third of our diet relies on pollinators , and let's review quickly why that is so . In order for flowers and fruits to form on plants , something has to move their pollen from the anthers of one flower to the stigma of another , and that's what causes fertilization to take place . And in most cases , that something is an insect , a butterfly , moth , wasp , fly , beetle or , in many cases , a bee . Bees are by far the most efficient pollinator , for a couple of reasons .

Pam 1:40

They sure are , and for one thing they're built for it . Bees have special hairs and pollen collecting areas to help them transport that pollen . They can groom pollen from their bodies into these areas , which are sometimes on their legs , sometimes on their abdomen , so they can trap and transport more pollen than any other type of pollinator , and they're very motivated to do so . Bees actively collect and transport pollen . They are looking for food and they have found that pollen and nectar to be excellent foods for themselves and for their young . Bees also forage around their nest . So if nesting sites and plantings are provided to encourage native bees , bees will search for food nearby and that will help ensure the flowers are pollinated . All these factors make bees real pollinating superstars .

Lisa 2:37

So we thought that today we'd take a look at some of our favorite traditional Thanksgiving foods and the untold stories about the pollinators that help them get to our plates . For example , pumpkin pie . Do you guys do pumpkin pie at Thanksgiving ?

Pam 2:56

Oh , my gosh , we sure do Thanksgiving , and also the next day's breakfast , sometimes , if there's any leftovers . I remember the time , however , when Doug put salt in the pumpkin pie instead of sugar . Oh oh yeah , it was bad . Well savory , definitely savory . But we also have roasted butternut squash or delicata squash . Yeah , we like all the squashes .

Lisa 3:23

Yeah , well , it might surprise you to learn, I mean , I was certainly surprised when I first learned that there's a bee for that , a special bee , the squash bee . And to help us learn all about the squash bee , we are so pleased to be joined by Dr Margarita Lopez-Uribe from the Department of Entomology at Penn State . Margarita , thank you so much for joining us today . Thank you for the invitation . It's a pleasure to be here . So , as I said , Margarita , I think most people are unaware of the existence of the squash bee . And you know , even though I know about it . So I'm out in my garden I grow a lot of cucumbers every year and I'm out in my garden and I'm looking in the flowers and I'm thinking , oh , I think , is that it ? Is it a squash bee or what ? So how do we ? Let's do a little squash bee 101 . Okay , just the basics to start with , because they do look a lot like honeybees .

Dr. Lopez-Uribe 4:23

A little bit . Yeah , they do . They are about the same size , I guess . What are the differences ? So the first thing and I'm going to use some technical words , but I will , you know , try to explain what those mean . So honeybees are what we call corbiculate bees , which means that they have a corbicula , which is a basket on their hind legs , right . So this is why when we , when we see honeybees on flowers and we see them gathering pollen , we see these pollen balls on their legs , right , they collect in their baskets .

Dr. Lopez-Uribe 4:57

Bumblebees are corbiculate bees too . Squash bees are closely related to honey bees , but they don't have a corbicula . So the females have a structure called a scopa , which means that they have these really long hairs where the bees , you know like , basically put the pollen to transfer that back to the nest . So for my eyes , that's something that I immediately can tell . Right like , does it have these hairy legs or does it have , you know like , flat hairless , you know like legs , I think .

Dr. Lopez-Uribe 5:31

The other , the other difference is the squash bees are the thorax of the squash bees is a little bit hairier than than honey bees , and the males of a squash bees are very abundant in flowers , unlike honey bees , right , like we rarely see drones visiting flowers or if ever , I guess Male squash bees are super important pollinators and they have this really cute yellow spot on their clipeus under , you know , above , their mouth parts . So yeah , so those are some of the differences that I think I use to differentiate them . They also fly in a very different way . So , yeah , if you are passionate about you know like , learning about these squash bees , just try to you know like see them on the flowers , as squash bees are very fast flyers . Honey bees are a little bit slower , so just from the behavior you know like , I also think you can tell them apart .

Lisa 6:28

That's very helpful When I see a bunch of a bunch of bees in the closed flowers , is that likely to be a male squash bee ?

Dr. Lopez-Uribe 6:41

That is a great observation . Yes , so some males and this is true for solitary bees , males emerge and they don't really have anywhere that they call home where they can go back and , you know , protect themselves . So a lot of male bees use other structures and squash bees actually sleep inside wilted flowers . So it's not rare to open a wilted flower in the morning and see a bunch of cute males .

Lisa 7:09

Just you know , like waiting there , it's like they've been propping up the bar all night , right , of course the description of the male foraging behavior in the booklet is hilarious .

Pam 7:22

Yes , do tell , do tell . They hop from flower to flower in search of a female and they'll form these large ball of bees that will fall right out of the flower .

Dr. Lopez-Uribe 7:36

Oh yeah , that is . That is just a treat to watch . You know , like the male's going crazy and you know this is very common . Pollinator porn--Yeah , you can call it that .

Lisa 7:52

But she won't , because she's a professor . But we can , it's our podcast .

Dr. Lopez-Uribe 7:59

That's very common for solitary bees that nest in aggregations . So I've seen those behaviors in you know several species . Where you see those nest aggregations underground . You know when the females are first emerging . Usually the males emerge a few days earlier . So it is not uncommon to see that scouting behavior , for you know females and yeah , so they're hanging around waiting for the ladies .

Lisa 8:30

Okay , so we've been talking a lot about solitary bees and we should probably backtrack for a second and explain for our listeners the difference between social and solitary bees and who's who .

Dr. Lopez-Uribe 8:43

Yeah, thank you for reminding me of talking about that , because that's a huge misconception that a lot of people have . I think we're mostly introduced to bees through honeybees because I mean we do bee keeping , we know about honey and we learn about the fascinating societies that these bees have . But the reality is that , the social behavior of bees is really actually rare among these . So about 90% of the bees do not form any sort of group and really the definition that makes a bee solitary is that the mom will never meet the brood , by the time the , the new generation emerges , mom is already dead in the solitary bees . In social bees , mom interacts with the other generations in the colony and that can be one or several depending on the different species .

Lisa 9:41

So most bees are not like honeybees , not social bees .

Squash Bees and Their Nesting

Pam 9:47

Well , when people hear the term ground nesting , they immediately think of a run-in with a yellow jacket , a hornet , and that's what they think of . So they can't really see beneath the ground to see what's going on . So in the case of a squash bee , for example , could you explain the nest architecture , how the female proceeds to build her nest and provision for her young ?

Dr. Lopez-Uribe 10:13

Every time that I tell this story I just it makes me think about how fascinating this is .

Dr. Lopez-Uribe 10:17

So again , these species , are solitary .

Dr. Lopez-Uribe 10:22

Each female has to do everything for her nest , including digging these like deep tunnels underground , and so there is usually kind of a main tunnel that is what connects to the surface , and from the outside these nests look like you know , ants nests , like there is kind of a little mound of loose soil from the stuff that the female has been digging out , and then from that main tunnel that are secondary tunnels that branch out , and then at the end of those secondary tunnels the female makes what we call a cell , which is really the cavity where she's going to put all the pollen and nectar for the developing larvae .

Dr. Lopez-Uribe 11:06

So basically , you know she's going to dig these tunnels , make this cell and they line the cells with some salivary secretiosn and abdominal secretions to make them a little bit protected from water and other things , and then she goes out of the nest , collects all the pollen and nectar , brings that back , and then , once there is enough food for one cell , then she lays an egg and then she closes that cell and then she will never see what happens after that . And she does that throughout her life . Depending on where squash bees are , they can probably make , I would say probably like about 10 or 12 of these , cells in the season . So yeah , compared to , for example , honeybees , the reproductive output of these solitary bees is significantly smaller .

Pam 11:59

Oh , that's so interesting . Yeah , is it safe to walk around the mounds ? Because somebody will probably ask this-- Is it safe to walk near and around ?

Lisa 12:08

Because , like , if you go to pick your own pumpkin or something like that , people might be worried .

Dr. Lopez-Uribe 12:13

Yeah , yeah , so that's a really good question . Most female bees have a stinger . So if you step on them or you know , if you try to grab them , they will sting you because they will feel threatened . But solitary bees don't have the same defensive behavior than social insects do . So that is the main difference between the solitary bees making their nests underground . So unless you're walking with bare feet and you step on a female , they won't feel threatened and they won't try to sting you . If you walk by , if this happens with a yellow jacket or a bumblebee nest , right , there is that defensive behavior and there is a higher chance that you will get stung .

Lisa 13:10

So squash bees are pretty peaceful , pretty easy to coexist with . Yes , so it's safe for us to walk . But we wouldn't want to do that right ?

Dr. Lopez-Uribe 13:28

I mean disturbance happens right , either by us or animals who may be walking by . So the worst that can happen is that basically , when the when the bees-- and this is true for all bees-- when they leave the nest , they do something that is called an orientation flight , and so basically they leave the nest and they check for a few landmarks to know how to come back home ,

Lisa 14:01

We like to look from all angles .

Dr. Lopez-Uribe 14:03

Yes , there you go and then you say , okay , I'm next to this green car , right , of course , but if that green car leaves , we may be a little bit disoriented . So the same thing happens with bees . The worst that can happen is that it may take them a little while to find their way back to their nest , and we've done some studies on , their behavior . They do make mistakes sometimes , so sometimes they enter the wrong nest and then if the female is there, the other female is kind of like pushed out and she's like no , this is my house . You go and look for your house . Yeah , I think that's probably the worst that can happen . Generally it's not a terrible thing to do to walk nearby .

Lisa 14:54

Good , good . And as far as the appearance-- again in my Cucurbit patches , I'm always looking , every year , I'm just looking for those tunnels , you know , like what's the diameter of the hole ? Kind of what size are we looking for ?

Dr. Lopez-Uribe 15:13

I think in centimeters . So I would say a half a centimeter--t he bee should be able to , you know , go inside the nest . When I see bee nests that have a smaller diameter , usually it's a sweat bee , that's going to be smaller , but definitely they are larger than an ant nest .

Lisa 15:36

So would it be like a pencil ? Pencil eraser type .

Dr. Lopez-Uribe 15:44

Yeah , that's a great way of explaining the size .

Lisa 15:48

Well , I'll keep looking . I haven't got lucky yet , but I'll keep at it .

Pam 15:52

The photographs on your website of the nests are a wonderful way for people to see what they look like . The aggregation under the squash plants is beautiful .

Dr. Lopez-Uribe 16:08

Yeah , and they can nest in those aggregations , but it's not uncommon to see maybe just one nest --so there is some flexibility on whether they decide to do these large aggregations or not .

Lisa 16:24

Okay , so diet . So they're what we call a specialist bee , right ?

Pam 16:30

Yeah , yeah , we want to know about the pollen .

Lisa 16:34

Yeah , just what is so great about that pollen ? Is it like the pumpkin spice flavor , or what ?

Dr. Lopez-Uribe 16:40

No , it's so , you know , it's a fascinating story and I don't think we know everything yet . These squash bees , which , by the way , we only have one kind in the eastern part of the US and in Canada , but there are about 22 species in , you know , in the Americas , right ? So this is just kind of like one that we happen to have here , but in the South there is greater diversity , and all of them exhibit these very narrow , tight association with Cucurbit plants . So this is not totally rare to have bees that have that very close dietary specialization . What is special about this pollen ?

Dr. Lopez-Uribe 17:30

We don't know . Something that we do know is that honeybees and bumblebees cannot eat this pollen . When you see bumblebees and honeybees in a squash flowers , they are drinking nectar and if they are leaving a male flower , you will see them standing on a leaf , kind of like grooming out the pollen because they don't bring it back to the nest . There are some experiments that have actually demonstrated that if you only feed Cucurbit pollen to bumblebees , they actually die . Like the colony cannot reproduce , the females get really sick . Apparently , there is something about the structure of the pollen that actually damages the gut of the bees . So , yeah , so it's fascinating and we don't really know how is it that these bees develop or , you know , evolve these high specialization on a floral resource that seems to be completely unused by other bees .

Lisa 18:45

Wow , that's so interesting because I see bumblebees all the time in there .

Lisa 18:50

NI have something else to watch for , which is great .

Pam 18:55

That's a fun squash bee fact if I've ever heard one .

Lisa 18:59

For sure , and I know a lot of your work has sort of centered on commercial growing . Pennsylvania , I think , is second only to Illinois in commercial squash production . So what I want to know , and what probably our listeners would like to know , is how can we encourage squash bees to make a home in our home gardens ?

Dr. Lopez-Uribe 19:24

Yeah , I think it's fairly simple . You know I've done it in my house . I live in a suburban neighborhood , there are not a lot of agricultural fields in close proximity to my house I f I have like six plants in my garden , squash bees find their way . Of course , the more plants you have , the more bees you will be able to support . But yeah , really is all about having the plants and the bees will come .

Lisa 20:05

Yeah , and being sure not to till right ? Don't till up the ground .

Dr. Lopez-Uribe 20:11

Yeah , I think that the story with the tillage is a little bit more complicated than don't do it . It is the deep tillage that is very bad , but actually the disturbance of the soil at the kind of surface is actually not a bad thing because it's loose for the bees to use right and to dig . So it's kind of this intermediate tillage that is the sweet spot for squash bees .

Lisa 20:43

Well , that's good to know and I found that interesting that the next generation will come can come back to that same spot . This was my question as a gardener who has struggled with squash bugs , which is totally different , you know , and one of the things that they always tell you , if you have a problem with squash bugs , is to not plant in the same place every year but to rotate around as much as you can . But I would think , in a typical suburban garden , it's not so big that they're not going to find it if you're rotating the plants , right ?

Dr. Lopez-Uribe 21:24

Yeah , I guess it's because some of them , I think the life cycle of squash bugs, they need like the roots of the plants , so if you don't remove the plants , then they will kind of finish the life cycle . But the rotation of the plants , as long as it's not too far , it should not be completely detrimental to the bees either , they will find the plants .

Pam 21:52

Good , I have one more question .

Pam 21:56

I'm so fascinated by ho the population expansion of squash bees , with agriculture moving east , could you talk a little bit about that ? That's so fascinating . When other pollinators are on the decline , the squash bee populations are expanding .

Dr. Lopez-Uribe 22:16

Yeah , it's a fascinating story and the story is that squash bees are not totally native to Eastern North America . They are here because humans , with the domestication and cultivation of the plants , basically created habitat for these squash bees outside of where they are native from , which is really deserts in the southwest of the US and northern Mexico . So , yeah , it really is a great example of how humans have modified ecosystems since a long time ago . We are modifiers of our environment and the power that providing floral resources for bees has . So , basically , by creating these habitats , these bees have been able to move with humans and establish and flourish . So I think , for Master Gardeners , I think this is a very empowering story .

Pollinators and Thanksgiving Foods

Dr. Lopez-Uribe 23:18

If you provide the floral resources , in many cases that may be the one thing that a bee needs to establish in an area .

Lisa 23:31

So if you plant it , they will come . They will come .

Dr. Lopez-Uribe 23:37

And this has happened in many different systems . We think that species are locally extinct , right , and then people plant the right floral resource or look for them in the right plans , and then the bees are there . So , yeah , I think it's a fascinating story .

Pam 23:59

Thank you so much for taking the time .

Lisa 24:02

Yeah , we really appreciate it and , listeners , we will include a link in the transcript of this show to the wonderful booklet that Dr Lopez Uribe has put out: The Biology and Pollination Services of the Squash Bee . It's really great and it has been my Bible in learning about the Squash Bee . So , anyway , we just so appreciate you taking the time and we wish you a very happy Thanksgiving .

Dr. Lopez-Uribe 24:34

Thank you , you too , and thank the Squash Bees for all the Squashes that you always eat and all the pumpkins in Halloween too , thank you .

Lisa 24:49

Of course , pumpkin and squash aren't the only foods on our Thanksgiving table . Another dish that's very traditional is cranberry sauce . Now , some people like to make fresh cranberry sauce .

Pam 25:00

Oh , that would be me . I like the fresh cranberry sauce .

Lisa 25:09

And still other people have special recipes for various salads or desserts with cranberries , but it's really an all-American plant the cranberry . Now you might think of cranberries as growing in bogs in places like in the northeast New Jersey , Maine , but it might surprise you to learn that cranberries are actually native to parts of Pennsylvania too . Wild cranberries grow in the very acidic and glaciated soils in the northern parts of PA , and it's the cultivated varieties of these wild plants that are commercially grown for our Thanksgiving table . Now , originally , cranberries were called cranberries because of the shape of the flower , which , if you look at pictures , you can see the resemblance to a crane's beak .

Pam 26:00

And those flowers are interesting because , although the anthers and stigma are present on the same flower , they don't mature at the same time , so they can't self-pollinate . So rather they need bees to move the pollen from the mature anther to one flower , to the stigma of another .

Lisa 26:19

And that is where bees come in . Commercial growers will tend to truck in managed honeybee hives for the flowering period , but wild native bees are also really effective pollinators of cranberries . According to Rutgers University , there are over 20 different types of native bees that visit cranberries in New Jersey alone . Take bumblebees . They are excellent pollinators and they work longer hours than honeybees , and they can forage when it's too cold or wet for other bees . So they really come into their own in adverse weather conditions and heaven knows , we seem to have plenty of those these days and we will also find mining bees and leaf cutter bees and sweat bees and cranberry bogs , and they're all important to a good cranberry harvest . So thanks , wild native bees .

Pam 27:16

So when we think of some of the side dishes at the Thanksgiving table , such as mashed potatoes , yams or stuffing , I'm getting hungry . Many times , at least at my house growing up , they were mixed together with creamy butter , milk or cream . And you might ask well , what in the world do dairy products have to do with pollinators ? Well , as it turns out , dairy cattle benefit from eating bee-pollinated alfalfa and clover . Alfalfa is so highly nutritious it's a forage crop , an excellent source of energy , protein , fibers and minerals for dairy cattle . Cattle flowers must be cross pollinated to produce seed , and this involves the use of the alfalfa leaf cutter bee to acquire and move pollen among plants in the field .

Lisa 28:10

So there's a special bee for that .

Pam 28:12

There's a bee for that . So when you dig into those creamy mashed potatoes , you can thank this very efficient pollinator .

Lisa 28:21

So I hope this has given you some food for thought , listeners , and maybe some topics for discussion at your holiday table , maybe some topics that don't center around your personal life choices .

Pam 28:39

Or the latest political environment .

Lisa 28:44

So if you visit our website , you will find a downloadable Thanksgiving placemat that Pam created for us that you can print out

Pam 29:00

And , if you'd like , you can take a photo of your completed placemat next year feast . Email it to us and we'll be happy to share it on Facebook , instagram and on our website .

Lisa 29:12

And in the transcript of this show we'll provide a link to that and also a link to Dr Lopez Uribe's excellent booklet on the Squash Bee .

Pam 29:22

It has the most amazing illustrations and it's a really great resource .

Lisa 29:26

Yeah , it's incredible that it's just available to download for free . So take advantage of that , and we want to wish you and yours a wonderful holiday season , and we'll talk to you again in the new year . Happy Thanksgiving . RESOURCES: Thanksgiving placemat: http://www . snetsingerbutterflygarden . org/activities . html . Squash Bee Biology Booklet: https://lopezuribelab . com/squash-bee-biology