Lost in the fog of a cosmic storm Floating on
whimsical wavelengths is the norm Dancing through
the stars, chasing spectrums of light Welcome
back for your listening pleasure to Whimsical
Wavelengths, a science podcast. Now, I've got
some really big news. If you're a listener and
not connected to the show via social media in
any which way, you wouldn't know. Whimsical Wavelengths
was chosen by the American Writers Awards as
2026 podcast of the year in the science category.
Data still out what that means for the podcast,
but it is a milestone. The evolution from the
first episode till now, and you know what? It's
just getting started. This episode continues
that evolution as it's about a new paper with
a new guest. But before we get into that, a quick
content warning for this episode. We'll be discussing
eight -legged creatures, spiders, specifically
black widows. So if you suffer from a truly severe
case of arachnophobia, this episode might not
be your cup of tea. Everyone else? Congratulations,
you're about to learn something that will almost
certainly make spiders more interesting. Although
not necessarily less unsettling. Because today
we're talking about attraction, communication,
and how even when you don't have a voice, wings,
or particularly good eyesight, you can still
manage to send a very clear message that says,
hey, over here. Black widows are famous for a
lot of things. Their appearance, their reputation,
their name. But what they don't get enough credit
for... It is their chemistry. These animals live
in a world where sound doesn't carry very far.
Vision is limited. And wandering around blindly
is a great way to become lunch for something
else. And yet, somehow, males still manage to
find females. Which raises a pretty obvious question.
How? That's right. this is a themed episode or
at least it was going to be in an ideal world
this would have been just in time for valentine's
day that's the way i planned it when i started
writing it a long long time ago but whether the
calendar cooperates or not the sentiment still
works because this episode is all about chemical
love letters seasonal timing and how attraction
in the natural world is often far more subtle
and far more sophisticated than we give it credit
for The paper we're using as our guide looks
at Western black widow spiders, Lactrodectus
hesperus, and asks a deceptively simple question.
What exactly are females putting into their webs
that attract males? And does that signal change
with the seasons as time moves on? Minor spoiler.
They do. So today, to unpack how spiders flirt
without ever meeting, how chemistry carries information
across space, and why Valentine's Day shouldn't
really belong to humans anyway. Because if you
think dating is complicated now, imagine doing
it with eight legs and a web. full of pheromones.
To help us untangle the scientific web, let's
welcome our guest who did his PhD at the same
university I did, Simon Fraser University in
the Department of Biological Sciences. Now he's
the assistant professor at Animal Metabolics
at Ecology Lab at Griswold University. Please
welcome Andy Fisher. Thank you for having me.
I'm so glad you're here. When this came up because
my neighbor, he suggested having you on the show,
I was like, that's really cool. And the podcast
is a great place to do this. And I think everyone
in research has a story that brought them to
study something different and why they chose
those subjects. So how did you come to study
the chemical language of spiders? Because this
one isn't as obvious as looking up into the sky
and seeing the cosmos or some kind of visible
phenomenon. yeah well i was studying chemistry
and biology a long time ago in germany as a double
major and during during my first year at university
in biology class it became apparent that we we
know very very very little about spiders they
are very feared everyone has an opinion about
them but we actually scientifically know incredibly
little about them and later on when i had to
choose my research subject i wanted to combine
my chemistry background with my personal interest
with in this very dark taxa so we didn't know
much about them so i wanted to see what chemical
spiders use and and spiders use a lot of chemicals
when because most spiders are virtually blind
and they can feel very well vibrations on the
ground but when you want to communicate with
anything that is further away than a meter They
actually use their sense of smell. And even upon
contact, they use their sense of taste. And that's
their main communication language. So when you
think how a male finds a female, well, they smell
them. And it became, at the time, a hobby and
then a profession to identify the chemicals involved
in this communication. So I moved then to Vancouver,
to Burnaby specifically, and studied at Simon
Fraser, did my PhD there, how spiders chemically
communicate. And yeah, that became my job. That's
awesome. This is almost like asking the same
question twice, but I think it's still useful
to reframe it. So before moving towards the paper,
you're already talking about how creatures communicate.
You said the spiders were essentially blind,
but I think spiders have many eyes, don't they?
Yes, so most spiders have eight eyes, but the
very most spiders... They don't really use them.
They can see a shadow coming, or if it's day
or dark, is it night, or is it a dark corner
where I'm more comfortable or not? So that's
what they use their eyes for. There are very
few spiders, like jumping spiders, wolf spiders,
ogre -faced spiders, that use their eyes for
hunting. But all other spiders, yeah, not really.
What is that? Sorry, this is a complete aside.
We're already going on a deviation. But how did
they, like... With eight eyes, is there something
that's happened evolutionary that have changed
that system? Like they have so many of them,
yet they don't really use them. Well, they use
them. They use them just not for the same things
we use our eyes for. So we are very visual animals.
And we communicate very unaware with our sense
of smell and taste. We can talk about that a
little bit later. But for spiders, they... they
have their eyes very strategically positioned
across their head. So they can see if a motion
comes from behind or if something is in front
of them. They have 360 vision, almost 360 vision
on a cylindrical sphere. And they use their eyes
just for the same things we use ours for. So,
yeah. Okay, so you and I right now are using
sound to communicate. Then obviously humans use
visual cues, whether you're in traffic and getting
angry. And then there's also smell. Are there
any other ways to communicate? I mean, you mentioned
taste. Yeah, so the sense of smell and taste
we combine as chemical communication. So smelling
is basically the same thing as tasting, except...
that the chemicals we detect are in the air,
whereas upon taste, we have to have surface contact.
But other than that, it's basically the same
thing. It's chemical communication. Our tongue
can taste all kinds of chemicals, whereas our
nose can smell all kinds of other chemicals.
Other animals, they use a lot of vibration. So
vibration is the same thing with sound or substrate
-borne vibration. Sound is nothing else but airborne
vibration where... the air moves and this is
a vibration that we can hear. The same thing
happens with vibration on a table or sometimes
when you feel a seismic vibration, worst case
is an earthquake, where you see literally the
earth shake. Many animals are very attuned to
these seismic, sort of substrate -borne, tremulative
communications. Other than vibrations, electric
communication, that is an emerging field. So
when we think of electric fish, these are very
exclusive taxes. But over the last 10 years,
we started to realize that a lot of animals communicate
with electrostatic signals. So they obtain an
electrostatic charge as they move. through air
like a bumblebee for example and when they then
land on a flower they discharge locally on the
flower that changes the electrostatic profile
of the flower and another bumblebee can detect
based on the charge if the flower has been visited
recently by a bumblebee or not any other flying
insect the same any flying predator moves through
the as an insulated body through the air and
thus gets a charge over time And many prey animals,
for example, a caterpillar, can sense the electrostatic
field of a, for example, wasp as it approaches
and then respond with an anti -predator behavior.
Wow. Yeah, yeah. So there's lots of emerging
stuff happening on the communication front, but
the traditional and better studies is visual
and acoustic communication. well known and used
by the very most different types of animals is
chemical communication, both sense and taste,
and sense of smell and taste. Now I have another
deviating question before I get back on track.
I didn't know we were going to go into electromagnetism
here, essentially. So we can talk about, and
keep in mind this is not my wheelhouse, so I'm
really stretching my abilities here. Kind of
the evolution of communication was basically,
I guess, chemical and sound first, kind of the
first two, because things didn't have eyes, right?
You had to have some way of communicating between
bacteria, I would imagine. So where would electromagnetism
come into that, like the electrostatic? So we
don't really know when the different... modalities
so types of communications came about and we
know from different animals and when you compare
our sense of smell and taste which seems to be
the oldest the way we detect things is very different
from an insect which has antennae with which
they smell and taste which is again very different
to spiders they smell and taste with hairs on
their legs so it's very diverse we assume that
uh when you think of the most primitive life
form single cell organisms they can they can
sense chemical gradients in the medium they originate,
and then they can move towards or away from it,
which we call chemotaxis, which is based on a
sense of ability to taste or smell these chemicals.
Now, sound has very little effect on these water
-borne media. We don't really know, so light
seems to be a very important communication modality
to detect from the environment, to sense the
day or night, etc. But we don't really know how
these things evolved on this macroevolutionary
scale. All right, so now I've got to ask you
a famous question, a why question. And you've
already sold me. I think this is absolutely fascinating.
We should absolutely study the heck out of this.
But to someone who doesn't know a whole lot about
science, why study the chemical communication
or the pheromones or the language of love of
spiders and insects in general? Most chemical
communication is studied in insects, and most
of them because there are a lot of problematic
insects. When you think of a moth that lays eggs
and then the caterpillars eat all your apples
in your apple orchard, for example, if you identify
the pheromones, which are the chemicals used
for the female to attract the male, if you flood
that orchard with female pheromone, the male
cannot find the female anymore the female remains
unmated she cannot lay eggs your apples don't
get eaten you don't even have to spray pesticides
or you reverse the whole thing around you have
a trap where you lace it with pheromone and all
the males get sucked into that trap like being
attracted to the trap and then essentially being
removed from the micro habitat and hence your
females remain unmated and so you have a very
efficient way of controlling past organisms with
The pheromones. And a similar idea brought me
then also to Vancouver back in the day. I wanted
to find something that deters spiders. So a pest
management strategy, which Vancouver, Simon Fraser
University specifically, is most famous for their
former Center for Pest Management. And they had
a Master of Pest Management program, which is
super invaluable in training these these novel
ways of thinking how to control pests without
pesticides. And chemical communication is one
of the most effectively used ways of controlling
pests. Okay, well that seems like the perfect
segue to the paper we're discussing. Identification
in seasonal abundance of web and airborne sex
pheromone components of the western black widow
spiders, Lactrodectus hesperus. Before we get
to the experiment and the results, who is Lactodectus
hesperus? And the type of communication that
we're talking about here, is it like super common
among spiders in general? Or is this really like
for a small subgroup? Yeah, so Lactodectus hesperus,
so you nailed it right on, is a black widow,
as the name says. It's the western black widow.
She occurs from Mexico all the way up to... Northern
British Columbia, if you wish. Well, yeah, midway
up high. But we have a stable population in Tawasin.
We have a very stable population on Makuba Island
and also one in the Okanagan. So British Columbia
is very well featured for this spider. That's
basically the local black widow, which we have.
If you have one, it's that one. yeah there is
a concern for another black widow establishing
in bc but luckily they have not been no reports
yet so it's our endemic so the spider comes from
here and it belongs here and we wanted to know
how they use their chemical signals their sexual
signals to be specific throughout the year so
let me a little bit explain how the spider lives
the spider lives under wood logs at beaches and
the female lives for multiple years so she has
multiple seasons where she can attract males
males are much shorter lived they usually live
after they mature for maybe 90 days if if they're
lucky and so the female might want to attract
males when they are around so during the mating
season and we don't know and when you're a female
spider that sits on her web and doesn't really
leave her web and, you know, you're located underneath
this log. How do you know when all the males
are around? And how do you know when you should
start signaling, so releasing your attractive
scent, if you want to be among the first? And
we found in the study, to spoiler some results
already, that it is mainly the day length that
provides some information about the seasonality
and when the males are most likely to be around.
And that seems to be the most strongest predictor.
I'm sure there's something I missed. I'll circle
back to it at some point. I'm sure it'll come
back. But one thing that people are probably
going to instantaneously wonder is, like, you're
doing field work with spiders. These spiders
aren't exactly safe. I mean, if we call someone
who always kills their husband, we kind of call
them a black widow, right? So that's already
in the vernacular of humans. So how do you find
them, capture them, and, I guess, experiment
on them? Yeah, so the spider is likely not very
aggressive. That is a very good thing to start
out with. Yes, they have a medically relevant
bite, but the statistics tell us, at least from
the States, that 50 % of the bites are dry. No
venom is applied, if a bite occurs, right? That
high? 50 % is dry. That's what I mean, like that
high, like 50%, they don't even inject the venom.
And another 47 % of the bites are local symptoms.
Like, imagine a very strong bee sting. Like,
it's local muscle cramps, but it stays local
wherever you get bitten. It's very uncomfortable.
It's not recommended, but it's also not like,
okay, I'm going to die. In 3 % of the cases,
there are severe medical... conditions appearing.
When the venom spreads throughout your body,
as I just explained, it causes muscles to cramp,
a certain type of musculature. And if your breathing
muscles of your diaphragm are affected, you could
suffocate, which is the death of a fire widow.
But it is very rare that this happens, even among
the people who get bitten. And the next thing
is, as you asked how I work with them, well,
the trick is not to get bitten, which is fairly
easy with the spider because she's not aggressive.
I never had a female spider even give me a threat
pose of this kind of spider. They have it like
a dog lays its ears back. The spider has its
own threat pose. yes so the spider when you when
you disturb the spider first response she will
do is she will run away she will try to get away
from you that's her instinct if you block her
and really keep cornering her she has she usually
then lifts her two front legs and maybe her second
leg pair and to try to appear bigger that's what
i deem a threat pose which i have not seen in
the species by myself on my own i've seen videos
of it And then if you keep harassing the spider,
the spider has yet another level of defense where
she pulls out large droplets of sticky glue out
of her spitterettes and tries to wrap the attacker
in this. gluey mess which is very efficient if
you think it's a wasp attacking the spider like
it can very much immobilize the wasp against
us humans it has very little defense now but
if you keep cornering the spider she might bite
and that is something we wanted to avoid by any
chance so the rule of thumb is was never squeeze
a black widow ever ever with anything And additionally,
just to be on the safe end, we used, we wore
gloves, protective gloves when we worked with
these spiders. And we used very long tongs. So
to keep a physical distance from the spider,
never have intentional physical skin contact
with the spider. But even if it were to happen,
the spider is not super dangerous in terms of
aggression level. But yeah, we have had high
respect of the spider and I still do. i i'm going
to pivot back just one sec so you said and i
gave a bit of a surprise so almost 50 of the
bites don't even inject venom is that because
the venom is hard to make and it doesn't want
to use it unnecessarily or it's it's hard to
predict the intention of the of a black widow
yeah i assume that defensive bites without venom
use could be just because venom is pure protein
and relatively expensive to make. If there's
a form of venom metering in a decision, I cannot
assess. There is another big factor in there
is what, in the medically relevant literature,
the biggest problem is actually misidentified
spider bites, where people come around and say,
I got bit by a spider, I got bit by a black widow,
but it then later turns out that it wasn't a
spider in any form, shape, or way. And that is
actually the bigger medical concern around spider
bites. When people come and insist that they
have been bitten by a certain type of spider,
they get treated for it. But they have another
completely different medical condition, I don't
know, an infected bacterial infection from a
normal pierced wound. And if they didn't get
treated for a black widow bite, for example,
the underlying condition remains untreated and
can cause real medical problems. With black widows,
as I said, when we know that it was a black widow
bite because someone took a photo of the biting
animal or even captured it, that's usually the
gold standard. If you're not a professional,
definitely don't sweat it to try to capture the
spider after she bit you. There's no point in
getting bit again. There are a bunch of spiders
that look like black widows. but are not, which
are very, very common in and around houses also
in Burnaby. So these misidentifications are another
layer that comes into that. But of the confirmed
like widow bites, roughly 50 % are, as far as
we know, dry. That's crazy. Okay, well, let's
go back to the paper because I got to sidetracked
again. So this paper was all about the different
pheromones that are, I guess, embedded into the
web, depending on the baiting schedule, I guess
is the better way to say it. So you found different
chemicals, the chemical of the web changed over
the year? Yeah, so we found actually a very sophisticated
communication system. When you imagine you're
this black widow, and you're sitting on the same
web, basically in the same house the entire year,
and you're waiting in the house for a mate, and
you're not really leaving the house, and there's
no online dating. How do you communicate? You
can't go to the club. There's no alcohol. There
is no alcohol for these spiders. No, unfortunately
not, no. So how do you fund a mate? So these
spiders, if they were to release a smell, that
smell would vanish the moment they stop behaviorally
releasing it. So most insects, for example, moths,
they actually at a certain hour of the day, they
start pumping behind a pheromone into the air.
which is around only at that time on only for
that location because once they stop pumping
once the male had arrived they fly off and are
then on a completely different spot but these
spiders they are sessile on the same location
for them to only call during certain time winners
wouldn't be as beneficial so and this is exactly
what we found we found that these spiders they
put a chemical onto the web that slowly degrades
over the course of weeks And one of the degradation
products, so there's a chemical bond, it's an
ester bond. And when that ester bond is separated,
you release a short -chain carboxylic acid, which
kind of smells like stinky cheese or gym socks,
if you wish. Wait, did you isolate it and then
grow more of it? or you can buy that in a bottle
and it pure itself it's overwhelmingly stinky
but because these spiders release only so little
amount at a given time that it was actually almost
for us virtually impossible to detect the smell
compound by itself but so the spider releases
very constantly but very little amount at a given
time of this very very for a stinky compound
It's called butyric acid, so the acid of old
butter. And this is literally how it smells.
So what we found is that the chemical, the pheromone
the spider produces at the beginning that slowly
degrades, degrades, releases the smelly compound,
and then there is a rust. that doesn't degrade
that doesn't fly away and we don't know what
this rest is about but we could find both things
we could find that this this larger molecule
was present and then you break off a piece that
flies off which we cannot see anymore and do
you see the smaller piece and we could calculate
how much must have been released in that given
time of these two fragments now I just mentioned
that this butyric acid, so this stinky cheese
smell, attracts the males to the females. And
when they arrive on the web, the male can taste
that compound, the chemical the spiders have
produced in the first place. You know, the stuff
that is slowly being deteriorated. And that,
when the males taste that compound, it releases
a behavior in the male that initiates courtship.
where when he tastes that compound, he starts
bundling up the female's web. He starts cutting
silk strands. He starts adding his own silk and
bundling up to a tight ball. And we don't know
how or why, but somehow the female find that
incredibly sexy when her house is being destroyed
by the male. And then if she convinces him sufficiently,
then they mate. And in this species, so Electrodectus
hesperus, there's only 10 % chance of sexual
cannibalism. So the males survive most of the
mating encounters. Good for them. But they still
only live 90 days? Yeah, they're very short -lived.
So does that mean they get to mate more than
once? Yes, they might have the intention of mating
a few more times. We don't know really how often,
or I don't know offhand how often these males
can mate with how many females, but definitely
more than once. And the females, likewise, they
mate with multiple males. But again, once they
have had a few males, they might become more
reluctant to mate again. So, yeah, I'm still
kind of getting over the fact that the male is
destroying the web. probably repairing it terribly
at the same time. No repairing. No, but you said
he was adding his own web. Yeah, to bundle it
up. Oh. Like a gift wrapping paper around it
so that you cannot access it anymore. Like it's
literally boxed away. There is an ongoing research
project from us right now to investigate this
stuff further. What is happening here is, I just
mentioned that the chemicals are disseminating
from the web. So the female puts chemicals on
the web as she's building the web. And then as
long as the web is there, it has these chemicals
and these chemicals slowly fly off and attract
other males. But what happens when a male cuts
and bundles the female web up, this web does
become unattractive to other males. And we don't
really know how. Is it because he blocks that?
chemical reaction so that the female compound
doesn't fall apart and doesn't release these
butyric acid anymore or is it because it decreases
the overall evaporation surface or and this is
what our preliminary results point to maybe the
male at a male specific compounds like i am here
signal or i was here signal and that the tears
repels other males And this is what our ongoing
research right now is pointing towards. So it's
both a male -male signal, signals other males
like, no need to come here, this web is done.
And at the same time, a male -female signal is
like, look how sexy I am, I can destroy your
house. And then the female find that attractive.
There is potentially for the female the ability
to assess how much resources this male has. Because,
you know, males, when they mature, they stop
eating. They're these tiny little spiders. They
stop eating. And for these 90 days, they run
around and their only objective is to find a
mate, find those females. So when you don't eat
anymore and you produce a lot of silk, and silk
is pure protein, it can become costly. And so
it could be that the female can assess by his
bundling behavior, like the amount of silk he
adds to the web, how rich in resources this male
is and how good his quality as a potential mate
could be. That's an assumption we don't know
yet, but that's a potential explanation. That's
really cool. What about the female spider, though?
Is there some drawback to putting the pheromones
into the web? Does it cause the web to degrade?
Is there an evolutionary or is there a cost associated
to producing that pheromones? is there like why
why not just produce it year -round and hope
for the best instead of putting it only when
the males are available that's an excellent question
so when you read the biology textbooks all of
them basically say that pheromones are cheap
so it would make sense to actually max out the
production constantly produce all year round
if they're really cheap but when you then look
at the underlying studies there are as far as
i know like five studies they demonstrate that
pheromones are actually quite costly. And there's
a single study in a single animal where it seems
to be fairly cheap. So it might be cheap for
some animals, might be more expensive for others.
Here in this case with the black widow, this
pheromone they produce contains nitrogen. So
it's an amino acid derivative. And that usually
points that it's actually nutritionally expensive.
And we have done now several research. projects
including this one where we demonstrate the females
are not wasting that stuff they use it when chance
of encounter is high or necessary when females
get starved their production of pheromone goes
down when females get really old and you know
senescent then their pheromone production goes
down so it seems that there seems to be some
constraint associated with pheromone production
of in this spider that's fascinating so you're
almost i guess in some respects turning old ideas
on its head to some extent well that's what we
are always trying to do with science uh that
we're not driven by dogma but trying to always
well we observe something and then we have okay
how do we explain this and maybe our textbook
assumption is partially correct Right, so in
many cases they could be cheap, but in these
instances they're not, or maybe it's more granular,
maybe it's more widespread. I guess that's still
to be determined, I guess, eh? Yes, so there's
this whole theory based on the cost of a signal,
where if a signal is very expensive, then let's
say... translated for our terms like if you drive
a very expensive vehicle that kind of demonstrates
to the world or to potential mates that you are
a very wealthy man or you just have a very good
credit line which would be cheating in this case
right but so if if a signal for an animal is
hard to fake or impossible to fake then it would
be an honest signal it really reflects the condition
of the animal. That is the handicap principle.
There are lots of different theories around that,
but a very simplified version of it. Now, if
a signal is not expensive, then you can just
pump it out and then there shouldn't be a handicap
around it and there shouldn't be... much constrained
around it or selection pressure for honesty that
you can use it to assess the quality of something
now with this goes a little bit beyond the study
at hand but with a very close relative to false
black widow our research team found that when
females get starved for a long time like i'm
talking 40 weeks like a very very long time their
ability to produce pheromone goes down because
you know no food is hard to pump out stuff but
they cheat by changing the rate at which the
pheromone is being released so you remember there
was this chemical reaction happening on the web
that slowly degrades that stuff they produce
and releases the made attractant well When these
very, very starved females that really need a
mate, you know, when you're like, okay, I haven't
been mated yet. My only goal in life right now
is to pump out babies. And I just need a male
right now. Try to become more attractive to males
by increasing this release rate. So they produce
less pheromone, but they release the smell compound
much faster. in hope to attract a male now when
the male then comes and mates with these very
very starved females they barely produce offspring
so it's it's a it's very costly it's relatively
costly for a male to be deceived but because
this happens so rarely there's not a lot of selection
pressure against it the compound itself is costly
and an honest signal But somehow the females
can convert that caustic signal into a deceptive
lie. Now, we just also found out that the same
holds true for old females. So when you have
females that are 500 or 800 days past maturity,
that's a relatively long time. That's on the
top end of their life expectancy. And when they
have been unmated, their ability to produce pheromone
also goes down. But again, they increase this
conversion rate. And then males cannot smell
the difference between a very old female or a
very young female. But a very old female is by
far not as fecund as a very young female. So
there is ability, plasticity for cheating if
the need arises, but only if the need arises.
And that way, they only do it when a need arises.
then the system is honest and stable otherwise
it could become evolutionary unstable and be
favored in a different direction wow sorry i'm
just a little bit of shock that's awesome like
i did not expect this conversation to go there
and somewhere along the way i also thought of
a like i was before we got to the climax of that
explanation i was thinking man i wish you know
talking sometimes was more expensive because
sometimes my kids talk too much and it would
be nice if it just cost them a little bit more
now how how are these measurements made though
so like you've been telling us kind of like your
observations but to create those observation
lists of the chemicals requires some whimsical
wavelengths yeah so the detection of these chemicals
is is a field of study and it's in their own
in their own right These animals produce minute
amounts. Those are nanogram amounts. So that's
minute. That's a gram of sugar, but now 10 to
the power of minus 9. So that is a very, very
small number of not even a grain of salt. It's
much less than that of amount which they produce
per web. When we deal with these tiny, tiny amounts,
we have very little machinery available because
there are not a lot of field of studies that
use such high sensitive machines to detect these
compounds because usually we know what we're
dealing with. Is it like parts per billion, parts
per trillion? Well, a number with nine zeros.
One nanogram per gram would translate into 0
.01 parts per million. So these are very, very
little amounts these spiders produce. So we don't
have a lot of different tools available that
reliably detect them. And historically, for insects,
what used to go very well are gas chromatographs
that are coupled with mass spectrometers. A gas
chromatograph separates a mixture of chemicals,
and the mass spectrometer can... bombard these
chemicals that are separated, so each chemical
at a time, bombards them with an electric charge,
ionizes basically and breaks the molecule into
fragments and then detects and basically weighs
the fragments. Like imagine you have a house
of Lego and you smash it against the wall and
then you have all these fragments and that's
all you see. You see only the fragments. You
have to try to imagine how did the house look.
before you fruit against the wall right so you
have a bunch of yellows and reds and blues and
blacks and sometimes you have a have a wall and
sometimes you have a foundational square or you
know like sometimes some fragments are bigger
than others that give you a little bit more information
but yeah if you're if you're really unlucky you
only get the little littlest pieces and then
to reconstruct that that is very difficult But
yeah, that's basically how a mass spectrometer
works. And that is what has been used very efficiently
for insects. Now, spider chemical communication
is in its infancy, so we have very little understanding
of what is happening, mainly because spiders
seem to use compounds that are not detectable
by GC -MS, that are too polar, so too acidic,
in other words. and we found out that a different
machine that over the last 20 years got a lot
of appreciation and sophisticated development
called liquid chromatography which can be coupled
with mass spectrometry that it's a different
way of separating compounds basically and with
that machine we can now find these fragments
very well and but then you still are in front
of the problem with that machine you detect basically
all the compounds that are on a spider's web
not only the pheromone and then you need to know
how do i know now which is the pheromone and
we usually use a control group for that so we
use spiders of the same species but that don't
produce pheromone for example teenager females
or or teenager males that still build a web,
but don't produce the pheromone yet. Or you can
even use sometimes mated females, depending on
the species. And you compare the chemical profiles.
And now there are very, very sophisticated computer
algorithms that can compare these different profiles
very, very, very well. And calculate as the most
likely candidate for it to be a pheromone. And
with that, we can... then have an idea of which
the pheromone might be. Then we need to reconstruct
it from the mass spectra and hopefully have not
to use all kinds of other analytical tools to
really reconstruct that structure. And once we
have reconstructed the structure, which is just
an idea at this point, we need to find a chemist
who synthesizes the chemical in a lab, presents
it to us. We present it to the spider and ask
the spider, is this the stuff you like? And the
spider might tell us, nah. Wrong stuff. Or Spider
-Man tell us, yes, that's the right deal. Well,
actually I respond to it. And so we then have
a Fairmont identified. Once we have it identified,
the game becomes much, much easier. We can quantify
it. So we can see now, now we know what to look
for. Does what we look for change from January
to December? And we just measure it every month.
And that's what we did in the study at hand.
We went down to Tawasin, to a beach for an entire
year where we had spiders, which we collected
there locally. We had them in little boxes so
that they would build us a web. We fed them in
these boxes. But once a month, we collected their
web. And then we measured how much pheromone
was there. Wow. So even at the end of it all,
even at this sophisticated level, there's still
a little bit of guess and check. oh yeah yeah
i mean the the hypothesis or the the working
the methodology says it's there but the specific
how you put what the pheromone together is a
little bit of guess and check until you get it
right that the spider reacts to it yeah there's
a lot of guess and check and very often we won't
have sufficient information to actually make
a guess then we have to mass collect that pheromone
isolate it and use a different machine called
nuclear resonance spectrometry spectroscopy sorry
nmr and if we have enough material with that
we have a more sophisticated guess what compound
we might have yay more wavelengths okay so where
does this research go now i mean you've kind
of already you've already hinted at it where
it's going but layout the next uh the next where
to take this yeah as as mentioned we are currently
looking at these uh these age -related signals
that studies basically being wrapped up now and
we hope to submit it and publish it fairly soon
uh at the same time we're looking at these male
courtship signal is is a is there a male pheromone
and the silk the male uses during the courtship
which might deter other males that is an ongoing
project right now We also want to see how females
respond to the presence of other females. We
demonstrated in the past that these females can
smell each other based on their pheromone, so
they know how hard the competition is. And we
also know that they change their own mate calling
and also their web architecture based on the
number of females around them. We want to know
to what extent do females... So when you go in
a field... you find a female somewhere you're
very likely to find another female within the
same square meter but so they cluster in the
field so you have sometimes pockets within suitable
habitat but you find females and then you have
other pockets that look identical to us where
there's just nothing and we we don't really understand
this clustering behavior and i want to find out
currently with a project to what extent the females
use pheromone to inhabit that choice, like where
to settle, where to build your web. And these
are the ongoing projects with these Black Widows,
which we're doing right now. And we hope to uncover
a little bit more. Okay, so I got one random
question that came to my head because I remember
I take in a lot of random media science and otherwise.
And I remember not too distant past ago, there
was a cave. I believe it was in Germany, but
I could be wrong. It was in Europe where they
found, what was it, 20 ,000 spider individuals
living together in one interconnected web. Do
I remember that right? Yeah, I saw it too. It
was massive, huge web. And there were multiple
different species in the same web. Yeah, it's
massive. These web sharing events are quite stunning.
We don't really understand how that works. Right.
Just when you said different areas with clustering
and no clustering, for some reason that popped
into my mind. It's like, oh yeah, I read that.
But that seems to be more an all year round permanent
event. With Black Widow, we have a very fascinating
thing. You know, the winters can be quite unpleasant
in Vancouver. or raincouver as we used to call
it right these these spiders also prefer the
summer seemingly in the summer they're solitary
every spider has her own web they have their
own little area of the log and that's their home
but a team also from simon fritz university a
while back 15 years ago found out that these
spiders in the winter when it rains they tend
to do web showing behavior where the females
their webs kind of merge into each other. And
sometimes you find three or four females on the
same web. So they kind of have this sub -social
state where we don't really know why they do
it or how they do it. And for me, it's more importantly,
when do they decide to break up as a team? Because
these females can be cannibalistic. So I assume
that during the, that's a hypothesis I do want
to test down the road. I assume that when the
pheromone production, gears up for the warmer
months from the mating season, that is also the
signal for the females, like, okay, let's everyone
go their own way, at least for a few centimeters
in between us, rather than containing this web
-sharing behavior. Okay, so we're approaching
very quickly the last traditional infamous question.
But before we get there, anything you want to
call out on the podcast, perhaps upcoming work,
projects, something that you just read that was
cool, like anything, anything at all? Yeah, so
I would call out to work from the lab where I'm
now suited and where they found out how spiders
smell, that they smell with their legs, with
these tiny little hairs that was discovered pretty
much a year ago. So it's really hot off the press
and I'm really excited about finally knowing
how spiders smell and taste. They have two different
types of these hairs. They have hairs that have...
tiny little pores through which these airborne
molecules can pass and be detected that's how
they smell and then they have these other pores
which are tip pore where there's only an opening
at the very tip and with that with those they
can taste that i i find very very fascinating
uh yeah other than that i just mentioned this
age -related study that hopefully will come out
soon and um yeah that's pretty much about the
call -out section By all means, send me an email
with the papers, and I'll make sure they're either
in the show notes. I also have a website, whimsicalwavelengths
.com, where I will also link to them, so that
way people that are listening can find them if
they're curious. But now, it is the final question
of the interview. Your favorite science joke.
Difficult one. I had to think about that one
a while. So I thought, how does the male... Black
Widow know that his date is going well. I have
no idea. Well, if they had great chemistry, she
will decide to wait until dessert to eat him.
Oh, that was good. All right. Well, thank you
so much for taking the time to hop on Whimsical
Wavelength. I know it's late there, and it's
just midday here, so thank you. Thank you for
having me. All the best to you. Okay, that brings
another Whimsical Wavelengths episode to a close.
I know the audio was a bit echoey on that one,
but we'll take it however it comes, because that
discussion was pretty awesome. I learned a lot
about spiders, and I hope you guys did too. So
I'll see you again in two weeks with another
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