What we learn from insects’ kinky sex lives

So people are more afraid of insects
than they are of dying.

(Laughter)

At least, according to a 1973 book
of lists survey which preceded all those

online best, worst, funniest lists
that you see today.

Only heights and public speaking exceeded
the six-legged as sources of fear.

And I suspect if you had put spiders
in there, the combinations of insects

and spiders would have just
topped the chart.

Now, I am not one of those people.

I really love insects.
I think they're interesting and beautiful,

and sometimes even cute.

(Laughter)

And I'm not alone.

For centuries, some of the greatest minds
in science from Charles Darwin to E.O. Wilson

have drawn inspiration from studying some
of the smallest minds on earth.

Well, why is that?

What is that keeps us coming
back to insects?

Some of it of course, is just the sheer
magnitude of almost everything about them.

They're more numerous than
any other kind of animal.

We don't even know how many species
of insects there are because new ones

are being discovered all the time.

There are at least a million,
maybe as many as 10 million.

This means that you could have an insect
of the month calendar

and not have to reuse a species
for over 80,000 years.

(Laughter)

Take that pandas and kittens!

(Laughter)

More seriously, insects are essential.
We need them.

It's been estimated that 1 out of every 3
bites of food is made possible

by a pollinator.

Scientist use insects to make fundamental
discoveries about everything

from the structure of our nervous systems,
to how our genes and DNA work.

But what I love most about insects
is what they can tell us about

our own behavior.

Insects seem like they do
everything that people do.

They meet, they mate, they break up.

And they do so with what looks
like love or animosity.

But what drives their behaviors is really
different than what drives our own,

and that difference can be
really illuminating.

There's nowhere where that's more true
than when it comes to one of our most

consuming interests --
sex.

Now, I will maintain and I think I can
defend what may seem like

a surprising statement.

I think sex in insects is more
interesting than sex in people.

(Laughter)

And the wild variety that we see makes us
challenge some of our own assumptios

about what it means to be male and female.

Of course, to start with, a lot of insects
don't need to have sex at all to reproduce.

Female aphids can make little, tiny clones
of themselves without ever mating.

Virgin birth, right there.
On your rose bushes.

(Laughter)

When they do have sex, even their sperm
is more interesting than human sperm.

There are some kinds of fruit flies whose
sperm is longer than the male's own body.

And that's important because the males
use their sperm to compete.

Now, male insects do compete with weapons,
like the horns on these beetles.

But they also compete after
mating with their sperm.

Dragonflies and damselflies have penises
that look kind of like Swiss Army knives

with all of the attachments pulled out.

(Laughter)

And they use these formidable devices like
like scoops, to remove the sperm

from previous males that
the female has mated with.

(Laughter)

So, what can we learn from this?

(Laughter)

Alright, it is not a lesson in the sense
of us imitating them or of them setting

an example for us to follow.

Which given this, is probably just as well.

And also did I mention sexual cannibalism
is rampant among insects?

So, no that's not the point.

But what I think insects do, is break
a lot of the rules that we humans have

about the sex roles.

So people have this idea that nature
dictates kind of a 1950s sitcom version

of what males and females are like.

So that males are always supposed to be
dominant and aggressive, and females

are passive and coy.

But that's just not the case.

So for example, take katydids, which are
relatives of crickets and grasshoppers.

The males are very picky of who they
mate with because they not only transfer

sperm during mating, they also give
the female something called a nuptial gift.

You can see two katydids
mating in these photos.

In both panels, the male's the one on
the right and that sword like appendage

is the female's egg-laying organ.

The white blob is the sperm and the green
blob is the nuptial gift, and the male

manufactures this from this own body
and it's extremely costly to produce.

It can weigh up to a third
of his body mass.

I will now pause for a moment
and let you think about what it would be

like, if human men --
everytime they had sex

had to produce something that weighed
50, 60, 70 pounds.

(Laughter)

Okay, they would not be able
to do that very often.

And indeed, neither can the katydids.

And so what that means, is the katydid
males are very choosy about who they

offer these nuptial gifts to.

Now, the gift is very nutritious
and the female eats it during

and after mating.

So, the bigger it is, the better
off the male is because that means

more time for his sperm to drain into her
body and fertilize her eggs.

But it also means that the males are very
passive about mating, where as the females

are extremely aggressive and competitive,
in an attempt to get as many as these

nutritious nuptial gifts as they can.

So, it's not exactly a
stereotypical set of rules.

Even more generally though, males are
actually not all that important

in the lives of a lot of insects.

In the social insects --
the bees and wasps and ants

the individuals that you see everyday,
the ants going back to your sugar bowl,

the honey bees that are flitting
from flower to flower.

All of those are always female.

People have had a hard time getting their
head around that idea for millennia.

The ancient Greeks knew that there was
a class of bees, the drones, that are

larger than the workers, although they
disapproved of the drones' laziness

because they could see that
the drones just hang around the hive

until the mating flight --
they are the males.

They hang around the hives until
the mating flight, but they don't

participate in gathering nectar or pollen.

The Greeks couldn't figure out
the drones sex, and part of the confusion

was that they were aware of the stinging
ability of bees, but they found it

difficult to believe that any animals
that bore such a weapon could

possibly be a female.

Aristotle tried to get involved as well.

He suggested, OK, well if the stinging
individuals are going to be the males,

then he got confused because that would
have meant that males were also taking

care of the young in the colony
and he seemed to think that would be

completely impossible.

He then concluded that bees had the organs
of both sexes in the same individual,

which is not that farfetched.

There are some animals that do that, but
he never really did get it figured out.

And you know, even today, my students
for instance call every animal they see

including insects, a male.

And when I tell them that the ferocious
army ant soldiers with their giant

jaws, used to defend the colony are all
always female, they seem to not

quite believe me.

(Laughter)

Certainly all of the movies --
Antz, Bee Movie

portray the main character in the social
insects as being male.

Well, what difference does this make?
I mean, these are movies.

They're fiction.

They have talking animals in them, what
difference does it makes if they talk

like Jerry Seinfeld?

(Laughter)

I think it does matter and it's a problem
that actually part of a much deeper

one that has implications for medicine,
and health and a lot of other aspects

of our lives.

You all know that scientists use
what we call model systems,

which are creatures --
white rats or fruit flies

that are kind of stand-ins for all other
animals including people.

And the idea is, that what's true
for a person will also be true

for a white rat.

By in large, that turns
out to be the case.

But you can take the idea
of a model system too far.

And what I think we've done, is use males,
in any species, as though they are

the model system.

The norm.
The way things are supposed to be.

And females as a kind of variant --
something special that you only study

after you get the basics down.

And so back to the insects.

I think what that means, is that people
could not see what was in front of them.

Because they assumed that the world's
stage was largely occupied by male players

and females would only have minor,
walk-on roles.

But when we do that,
we really miss out on a lot

of what nature is like.

And we can also miss out on the way
natural, living things incudling people

can very.

And I think that's why we've used males
as models in a lot of medical research,

something that we know now to be a problem
if we want the results to apply

to both men and women.

Well, the last thing I really love about
insects is something that a lot of people

find unnerving about them.

They have