Welcome to Creature Feature Production of iHeartRadio.

I'm your host of Many Parasites, Katie Goolden.

I studied psychology and evolutionary biology, and today on the show, it's a Buggy Listener Questions episode.

I got a bunch of questions about insects, and I thought i'd answer them all at once, so I.

Hope you enjoy.

Let's get right into it.

Oh and remember, if you have a question that you would like answered, you can write to me at Creature Featurepod at gmail dot com.

Doesn't have to be about insects, but it certainly can be.

So let's get right into it, Hi, Katie, what do bugs c?

Specifically, what do insects see, especially the ones with large, elaborate compound eyes is like a dragonflies individual eye segment directly connected to their brains.

Does eye size correlate with brain size and intelligence?

Thanks love the show, Juanito.

Also some additional context from Juanito.

This question was prompted by reading Adrian Tchaikovski's Children of Time novel and the book A species of jumping spider Portia labiata gets accidentally uplifted to sentience and technology developing level.

The author's description of the iraqtid censorium is fascinating.

And you know what, all his books I've read so far investigate crazy interesting biology, invented the aliens, worlds, or real the cute little spider guys.

I just discovered Adrian Tryikovsky this year and I heartily recommend his books.

He studied zoology and psych before becoming an author.

Wow, that sounds a lot like me, except I haven't written about super intelligent jumping spiders, but that sounds very cool.

Thank you Juanito for the question and for the book recommendation.

I'll check that out.

So this is a great question about eyesight.

How insects see the world, how compound eyes work, if eye size correlates with brain size, and intelligence, all really really good questions.

So the broad answer in terms of insect vision is that it really depends on the insect.

Different insects have different kind of eyes.

Even insects who have compound eyes can have different types of compound eyes in different ways.

Those are wired to the brain.

But let's break down first the components of how vision is processed.

You have the hardware, aspects of the eye, the lens, the shape of the eye, the retina, whether the animal has rods, cones or both, or simply light sensitive cells that can tell the difference between dark and lights.

So there's a lot of hardware to the eye that will determine how the light goes into the eye and where it goes to.

And then the information has to reach the brain, usually through some sort of nerve cluster, and then the brain has to process the raw visual data, and after that other parts of the brain interpret those findings and those get sent down to other nerves that control muscles and reactions.

So there are multiple points from the light hitting the eye to the organism's experience where that light is being transformed, both physically by the structure of the eye, by like the lens being directed into the eye, and then once it's inside, how it's hitting the back of the eye, what it's hitting, the sensory cells, the structures inside the eye that are funneling the light, and then also how that data is perceived, So both how it goes from the eye to the brain, the wiring of the neurons that transfer that data, and then how the brain process is it.

So in terms of what something sees, it's a very interestingly subjective experience, even for us humans.

We might think our site shows completely objective reality, but if you've ever seen an optical illusion, you'll realize our brains do a lot of funny business with that light hitting our eyes.

There's a lot that happens between that and getting processed in our brain to the point where you can look at an optical illusion and see something very strange, because that's your brain working to try to interpret these signals and adding things in that may not actually be there.

So let's also explore this question of eye size and intelligence.

So ie size and brain size are not always correlated, and brain size isn't always correlated with superior intelligence.

You have some things that might have really big brains and not necessarily be as intelligent as something that has a smaller brain.

Right, we certainly don't have the largest brains in the world, but we're very intelligent.

But in general, the general trend is that brain size can and does correlate with intelligence.

It's just not a hard rule.

There's many, many exceptions, and a similar thing happens with brain and ee size, or say like sensitive sensory organs and brain size.

So there are some studies that find that eye size is positively correlated with brain size, though it's highly dependent on the type of animal.

There's been some research on frogs that find eye size and brain size are linked, but studies done in guppies the fish found that eye size and brain size were positively correlated, but it did not actually predict better visual acuity or necessarily intelligence.

So the idea behind brain size and eye size or eye complexity being related is a good one.

Naturally, bigger eyes and more complex visual processing should require more space in the brain are at least more complex brain folds.

We do actually see this kind of correlation in dolphins who have massive auditory processing parts of their brains to help with the complex task of echolocation, and in humans we have huge visual processing areas of the brain and complex large eyes and very complex vision.

But some counter examples.

You have the tarsiir, which is a tiny primate who has disproportionately large eyeballs.

They're so big that they can barely fit in its head.

They can't turn in their sockets, so if it wants to look around, it has to move its whole head rotate its head around, and its brain is not that big.

In fact, its brain is smaller than one of its giant eyeballs.

Also, its brain is relatively smooth, and so the trade off seems to be that it has ditched a lot of its other brain mass, say like olfactory brain mass or other you know, parts of the brain in favor of a disproportionately large visual cortex, which is still small but enough to take in the visual data from those giant eyeballs, which are designed to see at night for feeding on nocturnal insects.

Speaking of nocturnal insects, they have managed to develop a keen night vision despite often having small eyes and small brains.

They manage this with clever trade offs.

Instead of seeing clear, crisp images like we do, they see very slow course images with high contrast.

So this allows them to react to threats at in the night in the darkness, or to find mates while everything kind of looks like an overexposed black and white image that has been repeatedly compressed until it's a grainy bunch of pixels moving in sort of delay slow motion.

Other insects have very different visual experiences.

Fruit Flies have eyes and brains that work together to allow for very rapid responses to visual information with sharp crisp edges, so kind of quite different from these nocturnal insects.

Many insects see colors that we can't perceive, like those in the ultraviolet range, which allow them to zero in on flowers who signal to them with secret colorful runways to aid in pollination.

And this is the case for dragonflies, who can either be pollinators, they can also be predators, but they have those big, impressive compound eyes.

Compound eyes are made up of a bunch of distinct units called omatidia, which each one comes with a lens, a cornea, and photoreceptive cells.

So they are these like individual units of vision.

Whereas you compare it to our e we have one lens, one cornea, and then a now with a bunch of photoreceptive cells at the back.

They have just like a bunch of these units.

Each one has a lens, in acornea and photoreceptive cells.

There can be tens of thousands of these on a single eye.

Different insects have different ways in which these compound eyes are connected to the brain, different methods of resolving the mass of tens of thousands of single units of information.

Sometimes individual units are clustered together in processing for a more sensitive but lower resolution image.

Others are more complex with an increase in neural wiring for higher resolution and still sensitive vision.

The reason not all the eyes maximize resolution and sensitivity is because this precise wiring is a higher neural load, so some insects will trade off for less neural processing for a lower resolution image whatever is needed most for survival.

Dragonflies specifically have eyes that are highly sensitive to color, even more so than human eyes.

They also have three hundred and sixty degree vision with about two hundred images per second, meaning that they see in bullet time, basically slow motion.

Most of their brain is dedicated to visual processing, like eighty percent of their brain, so they see a highly colorful world with ultraviolet and polarized light.

It maybe being a dragonfly would sort of be like taking in a slow motion movie at an IMAX theater that's really brightly colored all around you.

But again, it's kind of hard to say how they actually experience this, right, Like, we can't avatar into a dragonfly brain.

We've got our human brains with our human feelings and thoughts about what we see in our visions, so it's very hard to know what they actually experience, but we can kind of say this is what the information that is reaching their brain is very interesting, A very different way of viewing the world.

Sounds very trippy.

Onto the next listener question.

Hi, Katie.

After the first rain of the season, ants began appearing in my house.

Luckily, I have indoor ant traps, so I am not expecting any ant ant ant mageddon happening.

However, as I was observing the hapless creatures harvesting the poison in the ant trap, I began to wonder would the colony ever evolve to become aware of the man made poison, like how some species of ants are aware if one of their own is carrying the Cordyceps spores and would take action to get rid of the infected ant.

The ant traps are designed so the ant would carry the poison back to the nest and henceforth killing the whole colony by sharing the poisonous food.

At this point, I'm at the edge of a rabbit hole that I'm hoping not to fall into because I started reading the ingredients of the ant trap, which is point zero one percent avermect and B and ninety nine percent sent other ingredients and I definitely don't know what any of that really means.

Anyways, I would love to hear your thoughts before I get too carried away.

Thanks Jessec Hi Jesse, this is an amazing question.

First, let me just give some context.

She mentions.

First, let me give some context.

Courtceps are mentioned.

The courdyceps are spores of a fungus that can infect various arthropods, including ants, and so ants have learned to identify an infected individual and carry them far away from the colony so they don't infect the rest of the colony.

So there are two ways ants might thwart threats or poison evolution or learning.

So evolution is a very slow process over many hundreds thousands, hundreds of thousands, or even millions of years.

So for ants to develop an innate instinctive behavior towards, say, human ant bait traps, we would probably need to co evolve with them for quite a while, but it would be possible.

Some evolutionary traits already seem to act as potential protection against poisoning.

So some ant species have worker ants that act as living larders.

These are usually older workers who consume some food source and just kind of stand around and offer it to other ants via regurgitation, kind of like a living vending machine.

This could potentially help dilute toxins or simply kill off the ant that has ingested all of these toxins, and so it may act as a kind of buffer between these ants that have these sort of living larger members of the colony eating a bunch of food and then offering it to other workers after it's already been diluted in its gut.

But it's not a strategy that has evolved specifically for ant traps or ant poison or toxins, but it may be a separate benefit.

This is a behavior that's evaulved for things like surviving famine, for economizing food gathering, things like that, but it could have the impact of helping them survive human traps.

But ants do have the capacity to learn, particularly as a colony, and this is a faster process than evolution.

You can have a colony adapt to some threat or something within a matter of a single generation just by learning.

So Argentine ants have shown signs that as a colony they are capable of learning about poison bait and change their behavior in response to it.

So the cleverness of ant bait is that it has a delayed response, so the ant eats it, it doesn't immediately die, which gives it time to you lay down pheromone trails to alert other ants about what seems like tasty food.

Bring it back to the colony.

All these ants come and they gather a bunch of it, bring it back.

Still hasn't killed them yet, and then finally it starts to set in and kill them off.

And by then, you know, hopefully for you and sadly for the ants, it's too late.

They've already brought it in and so a lot of them die.

But yeah, so this is very insidious.

It's a very clever way to kill ants.

But researchers have found that argentine ants, which are one of the most common ant species in the world, they are highly invasive, incredibly durable, really hard to get rid of if you've ever had an argentine ant invasion.

So this might be one reason why so argentine ants seem to be able to learn to abandon toxic food sources and human beita traps.

So one of the studies authors that was looking into this Argentina ant behavior entomologist Roxanna Johnson's happened upon this when she was trying to help a pediatric hospital get rid of their Argentine ant problem with baited traps and noticed that the ants simply abandoned the traps without poisoning the whole colony.

So she got some argentine ants, put them in the lab, offered out some food sources, some that was just benign sugar water and some that had boric acid in it, which is an ingredient that's found in these ant ant traps or ant poison baits.

And so what they found is that these ants learned to abandon the poisoned bait after about six hours, and in fact they had not managed to consume enough of it and bring back enough of it to destroy the rest of the ants.

Of a few individual died, but not the entire laboratory colony.

So the interesting thing is, we don't know how they know how to do this.

So clearly there is some sort of algorithm happening where the ants go to the tainted food less and less and the pheromone trail weekends, whereas it strengthens for the food source that's safe but the researchers don't know how they're determining the tainted food source is unsafe.

So still plenty of research that needs to be done on how these ants are learning to avoid the ant bait.

But we know that at least argentine ants and possibly other species of ants do have strategies to counter it and can learn to avoid it.

So yeah, so that is I would say learning is something that is it's not quite evolving to counter a threat, because evolution, that's that's a longer process that implies a fundamental intrinsic sort of change in the ants biology and species.

But learning is of course something that's really really interesting, and you could absolutely have ants eventually adapt and evolve to counter ant poison human made ant poison if it is, oh, if we co evolve with them for long enough.

All right on to the next listener question.

Hi, Katie and or whomever reads this.

It was me and my dog, that's who read it.

I was recently listening to the episode with Janet Varney where you discussed bugs as alternative food sources and invasive species from the pet trade.

I always want wondering if there have been any studies about the impact of industrial bug farming.

You discussed animals from the pet trade becoming issues in an ecosystem.

I guess I have several questions.

Is there an industrial bug farm, what does it look like?

And could a breach cause harmful spikes in a population to the flora and fauna.

Thank you, Laura, Hi Laura, this is a fantastic question.

I actually do know someone who researches crickets and has poked around cricket farms where they're raised as food.

I'll try to get her on the show someday to talk more about both crickets and her experience checking out the cricket farm.

So, in answer to your question, could is there this threat of insects being invasive if you're doing an insect farm?

Absolutely yes, So all farm animals and plants can become invasive, and this could be absolutely true of insects already.

There are insect farms, some used as food, like crickets being turned in into cricket meal or meal worms being turned into meal.

Some farms use them as animal feed rather than human feed.

Some farms use maggots like black fly larvae to break down food waste into frass, which is a nicer term for maggot poop that can then be used as a fertilizer.

So we do already have bug farms, but a large bug farming industry doesn't really exist yet, not in the way that other industrial farms exist.

So as you probably kind of instinctively understand, like, insects are very prolific, they're tiny, they're perfect candidates for becoming an invasive species.

So they often become invasive just by hitching a ride in cargo and accidentally getting dropped off somewhere they don't belong.

And they're so fecunned, they produce so much so many offspring, and they are highly adaptable typically that they're great at being invasive species.

So a farm where you have a bunch of insects, potentially insects that have been selectively bred to endure harsh conditions or to breed more prolifically, Yeah, that would be a prime spot for there to be an invasive event, right, that could certainly pose a risk.

In fact, we kind of already see that.

We have a big example of that, which is honey bees.

So honey bees, as cute and wonderful as they are, they are not native to the Americas.

We imported them to make honey for us, for farms and to pollinate crops.

The problem is that they can actually out compete native species of bees, which can both be harmful to the native bees themselves and also to the plants and the flowers that the native bees pollinate.

Because you don't always just replace one pollinator with another, you can have a really specific relationship between say a wildflower, and a native species of bees who have co evolved with a wildflower, and they are a specific size, exhibit a specific behavior that the flower has co evolved with, and so their whole pollination structure is based on this species of bee and not necessarily based on the behavior of a honeybe.

So you could, if you say, threaten a species of native bees because the honey bees are outcompeting them.

You could also threaten native plants as well.

So honey bees, I mean, I love them, right, and I love honey, but yeah, they are actually an example of what you're talking about.

Bees that are used in large scale farming who have become invain because you can't really how do you keep how do you keep a honey bee in a cage?

You don't they go around, and yeah, they have caused issues for the environment.

Also, Laura, your question is so important.

It is actually being asked by ecologists now as we're having more and more of these discussions and sort of proposals for having industrial scale insect farms.

So the ideas that insects are more ecologically friendly because the sort of feed to waste to protein output ratios are much better than say a beef farm.

So like cows are pretty wasteful when you consider sort of their waste and the amount of energy you have to put in per unit of cow meat, whereas insects are a lot more efficient in that respect.

But there are a lot of questions that ecologists are raising because we don't actually have these large scale industrial bug farms that are similar in scale to other types of industrial farms that we have currently.

So there is an article in Trends and Ecology and Evolution called Approaching Ecological Sustainability in the Emerging Insects as Food Industry.

So your question is essentially the subject of this paper by concerned ecologists who are asking the same questions as you and pointing out a lack of research on the risk factors of large scale insects farms and the many unknowns of environmental impacts of insects farms.

One of the points they bring up is the invasiveness aspect, the fact that these insects could get out, that these could be heartier than native species because we might breed them that way, and that they could cause destruction to the local ecology.

And there's also other questions like even though we do know that they're more efficient in terms of like feed in protein out, there's not a lot of data on how you actually how do you house that many insects?

Right, Like I do know from my friend the one he studies crickets that answers are very sensitive to things like heat, so in temperature, so you have to you might have to have really specific temperature controls for that many insects, both to make sure that they're eating and breeding and growing things like that.

So also you know, just like how do you how do you prevent there from being say like disease that wipes out all of the insects.

All sorts of questions in terms of how sustainable would they be and what are the risks to the environment that we don't really know.

I mean, I would still say that it's very promising, right, like the I think it's something that is worth looking into because our current industrial farming situation is not good.

You know, it's not it is bad for the environment.

It tends to be very wasteful.

Also, you know, there's a lot of ethical concerns in terms of the treatment of animals.

So you know, I think having insects as a potential alternative food source and looking into it is really important.

But it's also not something to just be done without actually considering things that you've brought up, like the invasiveness aspect and what are the what are the other potential implications of an industrial sized insect form and it's an impact on the environment.

So fantastic question.

Uh, you could you could?

You could be an ecologist because you're asking the very questions that they are asking.

H Well, thank you guys so much for your extremely thoughtful and intelligent questions.

I always enjoy them.

It makes me do a little bit of homework that I really like to do because it keeps me sort of I guess, more up to date with uh, with research and stuff that I might not think to look into, but you guys do, and so I look into it and it's great.

We all learn.

We're all learning together.

If you want to send me a question, you can write to me at Creature Future pod at gmail dot com.

Thank you, guys so much for listening, and thank you to the Space Classics for their super awesome song Exolumina.

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I'm not your mother.

I can't tell you what to do, but yeah, before starting a cricket farm with a bunch of mutated super crickets, do think about whether they will take control of your local government and install a cricket autocracy.

You know, consider it.

See you next Wednesday.