Press "Enter" to skip to content

Pollination – the delicate balance between bees and flowers | Jennifer Leavey | TEDxGeorgiaTechSalon


Translator: Peter van de Ven Reviewer: Denise RQ

I’m really excited to be here today

to talk to you about one of my favorite things in the world,

which is bees, of course, bees.

I wish I had

some kind of exciting story from my childhood

to explain what drove me to become a beekeeper,

but I never had a grandparent who kept bees

and took me into their beautiful apiary on sunny days.

I never had a scary experience with being stung a bunch of times,

and I’m not afraid of insects.

I actually started keeping bees

because I found that it would be a convenient model for studying science.

So, whether you are learning chemistry,

like acid-base chemistry or physics,

maybe you’re studying velocity or momentum in your lab,

or maybe you’re studying biology and genetics,

or differential equations, or databases, or whatever,

you can study bees through that lens,

and that’s what drove me to start studying bees.

Bees are fascinating creatures.

If you take a look at this picture behind me,

you see one of the most iconic images related to bees, right?

You see a picture of a bee on a flower.

And this is something that everyone learns about in elementary school:

the role of bees as pollinators.

So, you’ve all seen this occur before in your life,

and you’ve learned about what pollination was

before in your life,

but I’d like to challenge you

to look a little bit deeper at what’s going on in this image,

because this is the image that I’m very concerned

that in the future is going to be disrupted,

with huge ramifications for people and life on Earth in general.

So let’s look at this image.

We have a picture of a beautiful honey bee

sitting on a flower,

and this bee is visiting the flower

because she wants to collect nectar and pollen as food.

That’s a pretty straightforward idea: she’s foraging for food.

And because honey bees are social insects,

she’s not going to eat this food herself,

she’s in fact going to return to her hive,

and she’s going to use these nutrients,

the carbohydrates in the nectar

and the lipids and proteins that she finds in the pollen,

and she’s going to use that to feed her sisters, basically.

Bees divide up labor;

they’re social insects and they divide up the work of the hive.

Not all bees are foragers, but all foragers are female –

that’s just a little bit of trivia.

So, here she is on this flower, collecting nectar, collecting pollen,

and in the process, she’s doing other things, right?

The flower is not producing nectar for its own sake,

it’s producing nectar specifically to attract this insect here,

and the reason why the plant needs a bee to visit its flowers

is because plants are very bad at having sex with each other.

(Laughter)

Pollination is in fact the root for sexual reproduction for plants.

Plants can’t move, they’re anchored into the ground.

So, they need bees to do the dirty work for them.

This bee has visited another flower before she visited this flower,

and she collected pollen,

which is basically the equivalent of plant sperm,

and she brought with that pollen

half of the genes that that tree had in the form of pollen.

She’s going to bring those genes,

which will then mix with the 50% of this tree’s genes

to form an offspring.

So, very important things happening here:

we have the future reproduction of the bee at stake,

in the form of the food that she’s collecting;

and you have the future reproduction of this tree at stake,

in the form of the fertilization event that is facilitated by the bee.

When that fertilization event occurs, the flower will fall off,

and we see a seed form,

and oftentimes, that seed will be surrounded

by some kind of delicious flesh that humans enjoy.

That was an apple blossom that we saw before,

here we have a delicious apple tree.

This is significant because animal-pollinated crops

are responsible for at least one in three bites of food that we eat.

The situation is not entirely rosy.

The United Nations released a report last year

summarizing some of the threats that exist to bees,

and as a result, the threats that exist to our food supply.

So, if you can imagine a world without apples, without zucchini,

without cherries,

without cucumbers,

that’s the world that we would live in, in the absence of animal pollinators.

This UN report had a lot of alarming statistics.

So, 75% of the world’s food crops

are pollination-dependent.

This is a huge economic impact.

We have over 500 billion dollars of food

that is produced every year

that is dependent upon animal pollination.

The honey industry itself is a big industry

with 1.5 million tons of honey produced in every year.

We think a lot about honeybees when we think about pollination,

and in fact, they are responsible

for a lot of the pollination of the food crops in this country.

Some food crops, such as the almond crop in Northern California,

is dependent on the presence of migratory honey bee keepers

bringing their hives to the orchard each year

in order to actually set seed and produce fruit;

there are not enough native bees to do the job.

There are native bees in North America.

Honey bees, or Apis mellifera, is not a native species here;

it was brought with the European settlers.

There are 4,000 species of native bees present in North America, though,

and these are some of them.

They range from very small iridescent blue sweat bees and orchid bees,

to big fuzzy bumblebees, to bees that look like wasps.

They come in a variety of shapes and sizes.

Some are generalists, and will pollinate a variety of different plant types,

some are specialists and co-evolved

with a single species or family of plants to do the pollination for that group.

It’s scary, in part because the same threats to honeybees –

we’ve heard about honeybees being at risk, right?

Last year, in fact, had one of the highest rates of colony loss in recorded history,

with 40% of honeybee colonies perishing over the course of the year.

These losses can translate also into the native bee population,

and over 40%

of invertebrate pollinator species are at risk of extinction.

So, honey bees are not at risk of extinction;

people love honey bees, and they will continue to keep honeybees

and expand their numbers to satisfy their needs.

But people frequently don’t care

about the other 4,000 species of native bees,

so which are at dire risk

as a result of the same types of impacts that are impacting honeybees.

So, what are they?

Let’s talk about the threats to bees that exist.

The first threat that I’d like to mention is habitat loss, or habitat destruction.

Bees need food, and they need a place to make a nest.

Honeybees are cavity nesters,

they frequently form their nests in hollow trees,

but they can also form their nests

in hollow wall spaces, or trash cans, or a grill in your backyard.

So, in urban settings,

honey bees don’t really have a problem finding a place to live,

but other species of bees,

like miner bees, that burrow into the ground to make their nests,

can have an impact on their nest sites, depending on the land use.

Up here, we have two different satellite images.

This is Southwest Georgia, Moultrie, and at the center is Rossman Apiaries,

which is a major producer of honeybees in North America.

You can just see from the satellite image what the land use is like:

there are agricultural fields, there’s forested areas,

a good habitat for bees, right?

This is where we are now, here’s the sadly defunct Georgia Dome.

You can just see from the satellite image that the land use is very different,

and we are studying, on the Georgia Tech campus,

the impact of that change in land use on the number and variety of species

that are present in the Atlanta area.

We don’t know that this is going to have a negative impact on bees,

but we’re looking into it.

Another threat to bees is disease.

I mentioned before that there are many migratory beekeepers that are hired

to come to the almond orchards in Northern California each year,

in order for there to be a sufficient crop of almonds there.

As these beekeepers bring their thousands of colonies of bees

on tractor trailer trucks to the orchards in Northern California,

they’re bringing with them diseases that can then be shared between the bees

that have come from all over North America to visit those orchards.

One of those diseases is the Varroa destructor mite.

This is a picture of the mite,

and it is feeding on a developing bee, on the pupil form of the bee.

This mite is sort of like a tick that transmits diseases,

often in a way that ticks transmit diseases to humans and other mammals.

One of the diseases that it will transmit is a virus called deformed wing virus,

and that virus causes the adult bees to emerge with shriveled wings.

So, this poor bee will never be on an apple tree;

she will never go and collect nectar and pollen for her hive,

and as a result, the hive will suffer.

There is an analogous type of disease that humans are grappling with,

and have been grappling with for about the last year,

and that is the Zika virus.

I think you’ve heard about this?

So, Zika virus, again, a virus is transmitted by an arthropod vector,

just like deformed wing virus is transmitted by mites,

Zika virus is submitted by mosquitoes.

Same kind of situation:

if a pregnant female becomes infected with Zika virus,

just like if a developing bee gets infected with deformed wing virus,

the baby could be born with a malformed head,

with microcephaly.

So ironically, the approach that we’re taking

to deal with threats to people, like Zika virus,

leads us to our next threat to bees.

This is a real upper of a talk, isn’t it? Because we’re just going to leave here —

Next threat to bees are toxins in the environment, like insecticides.

The largest public health effort to stem the Zika outbreak last year

involved widespread spraying of residential neighborhoods

with insecticides, and there’s not a single insecticide

that will kill an adult mosquito that won’t also kill an adult bee.

So, pesticides are another big threat.

Pesticides also, in addition to their lethal effects on bees,

have sub-lethal effects, so in combination with poor nutrition

low doses of pesticides can have other problems for bees.

And the final threat to bees that I want to mention

is the effects of climate change.

These are a couple of maps that were produced by students

who were studying at Georgia Tech last summer.

They took this map, which was based on data of native bees

in the sort of southeastern United States, in current day conditions,

and then they applied a climate model to that map

to predict where the range of that bee would be in about 50 years.

And as you can see, the range has shifted significantly.

Similar work has been done by other researchers,

looking at the range of different plant species, different tree species.

So, that image that we saw on the first slide,

of the bee and the flower is very fragile, right?

It’s delicate; you need a flower, and you need a bee there at the same time,

in order for that to occur.

So, there’s a risk that as the range of plants change,

and as the range of bees change,

we could be compromising that timing of that specific interaction.

Oh, here’s the good news. Okay.

What can we do?

That said, I think there are things,

positive things that everybody can do to help make the life of a bee better,

to help ensure our food supply.

One of those things is to help conserve and create habitats for bees.

This is an image of some volunteers from Turner

that were out with Trees Atlanta,

last spring, planting fruit trees in West Atlanta.

Atlanta is a very green place; there are tons of bees in Atlanta.

We have a lot of trees in the area.

So, if we can maintain those tree populations, plant more,

we’re creating habitat for bees.

And it’s a good thing.

Other things that we can do is try to mitigate the effects of climate change.

We want to reduce our carbon footprint,

so if we can reduce greenhouse emissions,

we can help turn the tide on climate change,

and help preserve the range of our native species.

Another thing that everyone can do is to help support local honey production,

and sort of local methods of beekeeping.

Big commercial operations move thousands of beehives

from one place to another, all season long,

collecting nectar as they go to produce honey.

And that has a big carbon footprint, to truck bees from place to place.

It also spreads disease.

If you can support a local beekeeper

that keeps their bees in the same place all year round,

you’re going to help stop the spread of disease in some ways,

and you’re going to reduce your carbon footprint,

and you’re also going to have delicious honey

that’s produced from flowers in your neighborhood,

which is always delicious.

And the last thing you can do is rather than spray your yard:

spray yourself.

Using bug repellent on yourself is not dangerous to bees at all.

So, if you want to keep the mosquitoes away in the summer,

rather than turning to a pest control company to spray your yard,

just spray a little DEET on yourself before you go outside.

I hope that you have become more interested in bees, in this time,

and that you might consider also contributing

to scientific efforts to study bees.

We have a group of students, computer science students at Georgia Tech,

that are using images that individuals have uploaded

to Flickr of bees on flowers,

and stripping the metadata from these images.

Every picture of a bee on a flower that is taken with a smartphone, for example,

that has it’s location services turned on,

will include a timestamp and location information,

and that can be used to create maps

of when and where bee-flower interactions are occurring.

So, if you’re out, and you see a bee on a flower,

upload that image to Flickr,

tag it with the word ‘bee’ and the word ‘flower’,

and our computer scientists will find it and scrape it’s data.

And finally, here we are,

this delicate easily disrupted relationship between bees and flowers

is very important both to the future of plants on Earth

and the future of our food supply,

and I hope that you will join me in helping to protect it.

Thank you.

(Applause)

”

Be First to Comment

Leave a Reply

Your email address will not be published. Required fields are marked *