Archive For: Invertebrates

Rhynchotermes – the best of both worlds

If you read my previous post about blattodeans you might have noticed that I left something out. The post does not make a single mention of termites that belong in the same insect order. Yet my Blattodea gallery contains photos of some termite species. What is going on?

Make no mistake – termites are indeed included in order Blattodea. While they do not lay their eggs in cases (oothecae), they share many other attributes with roaches. Historically, termites were classified under their own order, Isoptera. This is what I learned at university during my entomology training a decade ago. However, times change, and with it taxonomy is rearranged according to new evidence concerning the relationships between groups. Termites have been found similar in their morphology and social behavior, as well as molecular phylogenetics, to wood-feeding roaches of the genus Cryptocercus, and both are now treated as sister groups under the infraorder Isoptera within the Blattodea. I will only say that although I welcome this update in termites’ taxonomical position, I found it difficult to get used to at first. Old habits die hard I guess.

Termites are truly unique because they are among the few hemimetabolous insects (lacking the pupal stage in their life cycle) to develop an eusocial lifestyle, with different reproductive castes, division of labor, and overlapping generations. In stark contrast to eusocial Hymenoptera (ants, bees, and wasps), termite colonies follow a different structure, often with a single long-lived royal pair responsible for egg production (as opposed to male Hymenoptera that die soon after mating), but also include a secondary reproductive caste. Workers and soldiers can be both males and females (in Hymenoptera – all females). From an ecosystem standpoint, termites play a vital role as detrivores, feeding on and breaking down dead plant tissue and wood. For this reason they rely on gut symbionts (protozoans, bacteria, and flagellates) that assist in breaking down cellulose.

One of the things you often learn about termites in an entomology course is that there are two types, easily distinguished by their soldiers: species with mandibulate soldiers (possessing jaws), and species with nasute soldiers (with a long nose). The mandibulate soldiers use their enlarged strong mandibles to physically attack and injure intruders. They cannot use their jaws for feeding, and are therefore dependent on mouth-to-mouth feeding from the workers. In contrast, the nasutes deploy chemical defense by secreting various compounds from their nose, mainly to use as deterrents against ants, but also with some effect over much larger predators such as tamanduas.

Why this long introduction? As things usually go in nature, and more specifically in arthropods, to every rule there is an exception. Last year I travelled to Costa Rica, and one of the species I was hoping to find was a very unique termite.

Armed nasute termite soldier (Rhynchotermes perarmatus)

Armed nasute termite soldier (Rhynchotermes perarmatus)

This monstrous beast is a soldier of Rhynchotermes perarmatus, a nasutiform termite. However, contrary to the “rule” I mentioned above, soldiers of this species possess both a chemically armed snout and well developed mandibles. They are now treated by taxonomists as being mandibulate nasute.

The neotropical genus Rhynchotermes contains several species, all have nasute soldiers with noticeable mandibles. However, only in two species the mandibles are massive – Rhynchotermes perarmatus and R. bulbinasus.

Armed nasute termite soldier (Rhynchotermes perarmatus). Combining elements from both nasute and mandibulate termites!

Armed nasute termite soldier (Rhynchotermes perarmatus). Combining elements from both nasute and mandibulate termites!

Rhynchotermes perarmatus is subterranean, nesting underground or under stones. These termites usually do not expose themselves to the outside world, but instead move inside covered tunnels constructed from soil particles. Inside these dark tunnels the stout workers run clumsily, carrying debris and compressed wood fiber back to the colony for food.

An intimate look at Rhynchotermes perarmatus termites crawling in one of their covered nest tunnels

An intimate look at Rhynchotermes perarmatus termites crawling in one of their covered nest tunnels

An active tunnel contains a thick flow of worker termites, and several soldiers scattered at the periphery, on guard.

An active tunnel contains a thick flow of worker termites, and several soldiers scattered at the periphery, on guard.

Rhynchotermes seems to be associated with slightly disturbed habitats, such as cleared forest areas or meadows used for cattle grazing. There are reposts of them active under aged dried out cattle dung, suggesting they may have a role in breaking it down and recycling the nutrients. In Costa Rica I found Rhynchotermes perarmatus under a heavily decomposed fallen tree, right besides a well-maintained trail. Still, after flipping the log I could not see them. I had to break open one of the galleries to get access to the action.
And the soldiers did not like that.

Armed nasute termite soldiers (Rhynchotermes perarmatus) crawling out to defend the workers

Armed nasute termite soldiers (Rhynchotermes perarmatus) crawling out to defend the workers

While the workers kept on running seemingly undisturbed, the armed soldiers started pouring out, seeking the intruder. Maybe this is the time to mention that termite soldiers are usually blind. They have no functional eyes, and rely on chemical cues and physical proximity for defending the colony.

"Fear me, ant!"

“Fear me, ant!”

Even tough beetles like this weevil know to steer clear of active Rhynchotermes perarmatus soldiers.

Even tough beetles like this weevil know to steer clear of active Rhynchotermes perarmatus soldiers.

To the human eye it seems like despite their menacing appearance, Rhynchotermes perarmatus soldiers do not do much. They walk around aimlessly, then suddenly rise on their feet and give a mute roar, gaping their mandibles. But what seems harmless to us is actually a well thought of strategy: the soldier’s head contains a special gland that secretes a cocktail of sticky odorous compounds from an opening located in the snout. It is easy to think of nasute soldiers as nozzle heads discharging glue, but in reality what Rhynchotermes discharge is a strand, not fluid. The idea behind this is to turn your enemy into a sticky mess and incapacitate it. This is effective in case of attacking ants, perhaps termites’ worst enemies. The chemical properties of the compounds may also have a role in disrupting the ants’ chemical communication. Sometimes during the interaction the termite soldiers stick to the ants as well, sacrificing themselves for the benefit of the colony. But what if this does not work? Then they can use their secondary weapon – the mandibles.

Armed nasute termite soldier (Rhynchotermes perarmatus) gaping its impressive mandibles

Armed nasute termite soldier (Rhynchotermes perarmatus) gaping its impressive mandibles.

The mandibles are curved (similar to those found in army ant soldiers) and double-hooked. I cannot help seeing them as reminiscent to the mandibles of young Epomis larvae. This is probably an adaptation to grab and hold on tight to whatever the termite is biting. I even tested it – not only the soldiers grab well, they also lock themselves in place. They are difficult to pull out, like a fishhook.

Let me tell you, these tiny soldiers can sure bite!

Let me tell you, these tiny soldiers can sure bite!

Another thing I noticed is that many soldiers had “broken noses”. I wonder if the snout has a breaking point to allow for a quick release of the gland’s contents onto the intruder. They too moved about clumsily looking for troublemakers to the colony, reminding me of a drunken guy trying pick a fight in a bar, broken bottle in hand.

Poor soldier got its nose broken

Poor soldier got its nose broken

Aren't these termites just stunning?

Aren’t these termites just stunning?

There is still much we do not know about Rhynchotermes. For example, in the case of Rhynchotermes perarmatus, the alate caste was described only recently. Some Rhynchotermes species tend to occupy abandoned nests of other termites, but occasionally they are also found in close proximity to active nests, bordering the neighbouring colony or right on top of it. It would be interesting to examine what kind of interaction they have with other termite species. Like a lot of things in nature, these termites do not conform to our neat labels. Their bizarre soldiers represent the best of both worlds. They serve as a reminder that nature is full of surprises, that rules are meant to be broken, and that you do not have to look hard to find something new and inspiring.

A Moment of Creativity: Reconsidering blattodeans

A while back someone asked me if I had any plans to put up a gallery page for blattodeans on this website. That was indeed something I had in mind; This is one of my favorite insect groups, so it would not do them justice if they are unrepresented here. I hate to admit, but my issue with uploading photos of blattodeans is mainly due to difficulties in identifying some of the species I photographed. Nevertheless, I am happy to report that the Blattodea gallery is now up and running.

Blattodeans suffer an extremely undeserved bad reputation. The majority of Blattodea species live in natural habitats such as forests, deserts, sand dunes, and meadows, leading a cryptic lifestyle away from humans. Only a tiny fraction of them, less than 1%, lives in proximity to humans and considered as pests. For this reason I decided to ditch the word “cockroaches” and follow Piotr Naskrecki by adopting the word “blattodeans”. In the sad reality that we live in today, the word “cockroach” often carries a negative connotation in people’s minds. It is associated with something unwanted, menacing, dirty, and harmful. This could not be further from the truth: many blattodean species help to break down decaying organic matter, making crucial nutrients available for other organisms. They are, along with ants and flies, nature’s cleaning service (you’re welcome). Some species are also important pollinators. And that is without even mentioning their numerous adaptations to avoid predators, their maternal care, and social behavior.

A forest blattodean nymph (Nyctibora sp.) with white "socks." If you don't think he's cute you might want to check your pulse.

A forest blattodean nymph (Nyctibora sp.) with white “socks.” If you don’t think he’s cute you might want to check your pulse.

A long time ago I had the idea of photographing blattodeans right after molting, while they are still fresh and pigment-free. My goal was to see whether people would recognize the animal presented to them, now that it lacks some of its identifiable characters. By the way, I have been doing the same thing with whip spiders.

Blattodean molting. Who knows what it is going to look like once pigmentation appears?

Blattodean molting. Who knows what it is going to look like once pigmentation appears?

The semi-transparent exoskeleton of a freshly molted Lanxoblatta rudis nymph allows a rare glimpse into the insect's internal network.

The semi-transparent exoskeleton of a freshly molted Lanxoblatta rudis nymph allows a rare glimpse into the insect’s internal network.

The first attempts were done with Periplaneta americana, a common species that most people associate with pests. When presented with an all-white Periplaneta, almost everyone said it looked “cute”.

Freshly molted male Madagascar hissing cockroach (Gromphadorhina portentosa)

Freshly molted male Madagascar hissing cockroach (Gromphadorhina portentosa)

Above is a freshly molted male Madagascar hisser (Gromphadorhina portentosa) from a colony we kept at the museum I worked at (for more details see my previous post). We used to isolate individuals that showed signs of an approaching molt, to use them in class displays for students. Large males like this one were always a special treat, with their impressive horns. I took this photo in 2006. Even though I have seen and photographed many freshly molted blattodeans, I still see this old photo as one of my best captures. There is something about it that speaks to people. They no longer recognize an insect they are repulsed by; instead many people see something that reminds them of a cat. Recently I was delighted to learn that this photo has provided inspiration for an artist: I stumble upon an article in Chinese encouraging people to learn more about blattodeans. It featured my photo (=copyright infringement), followed by a drawing of an innocent-looking girl wearing the male horned hisser as a hat. Cute girls with cat ears (referred to as nekomimi, or in the case of other animals’ ears – kemonomimi) is a popular theme especially in manga and anime in Japan, and the blattodean serves a similar purpose here. As a matter of fact, early on I gave my photo the title 猫ちゃん (neko-chan), which translates to “kitty” in Japanese.

Blattodean kemonomimi embeded from the article mentioned. Artwork by user 长得像人的割草机 on Weibo (see originals in the comment below)

Generally speaking, I find that a lot of people respond differently to white blattodeans compared to dark-colored ones. It is almost as if it is a completely different animal. What is it that makes us so susceptible to visual cues in the form of flat dark insects? There must be a reason for this sensitivity.

A molting forest blattodean (Nyctibora sp.) shows off its elegant golden wings

A molting forest blattodean (Nyctibora sp.) shows off its elegant golden wings

Some blattodeans are white by nature, like this beautiful species of Panchlora from Belize

Some blattodeans are white by nature, like this beautiful species of Panchlora from Belize

We used to joke at the museum that when it comes to human reaction, insects can be divided into two subgroups. The first subgroup contains “green” insects: these are insects that are perceived as friendly just by their appearance. They do not necessarily have to be green, but it helps if they are. This group contains ladybugs, grasshoppers, stick and leaf insects, smooth caterpillars, stout and furry moths, mantids, and katydids to some extent. The other subgroup contains all the other insects. Again, this division is merely a joke, but it is amazing to see just how many people follow this arbitrary division. To those who welcome ladybugs but put blattodeans in the “other” subgroup, I always remind that there are blattodeans out there that look exactly like ladybugs.

Male horned roach (Hormetica strumosa). Not as cuddly as the white "neko-chan", but pretty close.

Male horned roach (Hormetica strumosa). Not as cuddly as the white “neko-chan”, but pretty close.

Since photographing “neko-chan”, I have been working with other species of blattodeans, hoping to achieve the same result, however, I was not able to replicate that look. Maybe it was more than just timing the photo with the molting process. Maybe I also captured some of the hisser’s essence and unique personality. After all, he almost looks like he is trying to tell us something. Well, he does, all blattodeans do – but we never stop to listen.

Halloween special: My worst bug bite

Last week I gave a seminar in front of med students and doctors at Toronto’s University Health Network about medically significant arthropods. Because I am not a doctor I chose to focus more on the animals themselves, presenting their side of the story and what type of situations bring them to sting or bite humans. The talk went well, I was even able to share my first hand experience with botflies, which triggered some interesting questions from the students. After the talk, one of them approached and asked me – “So, what was your worst bug bite or sting?”
I replied that my body has a severe response to black flies and their bites, swelling like crazy that I can barely recognize myself in the mirror the day after. He seemed satisfied with my reply, however on my way back home it occurred to me that this was not the answer to his question. He did not ask me which bite or sting I disliked the most. He asked me of all the bites and stings that I’ve gotten so far, which one was the worst.
And that is a valid question. I have a history of getting injured while doing all sorts of stuff, and this includes an impressive list of arthropod bites and stings accumulated over the years. But there is one bite that holds the title “the worst”. One bite I will never forget.

Some background: Back in 2007 I took a trip to Ecuador with my colleague and mentor, Alex Shlagman. We worked together at Tel Aviv University’s Natural History Collections (now known as The Steinhardt Museum of Natural History), breeding local and exotic species of arthropods for research, teaching, and display purposes. As the manager of the live arthropods collection, Alex was, and still is, the best arthropods keeper in Israel. On the other hand, I had an extensive travel history under my belt, after crossing South and Central America a few years before. This experience gave me useful insights when tackling the husbandry needs of tropical insects we kept. Nevertheless, it bothered me that Alex, with his vast knowledge of those insects, has never experienced the rainforest and its staggering diversity in person. So I did something crazy and I decided to take him to Ecuador.

One of the places we visited was a biological station close to the Amazon region. Despite the heavy rainfall this area usually gets, it was extremely dry during our visit, which made it difficult to locate animals active during the day – it was just too hot. One afternoon we hung out close to the station’s access road, following leaf-cutter ants and other insects, and taking photos. While tracking leafhoppers I stumbled upon a bush covered with what seemed to be communal assassin bugs. They were quite unique in their appearance, with a shiny lime-green abdomen and black head and limbs. From a distance they looked like spiders.

Assassin bugs in ambush waiting for prey

Assassin bugs in ambush waiting for prey

I took a single photo and then I moved in to do something I knew I shouldn’t – I poked the bug with my finger to force it into a better “pose”.
And it got into a better pose alright, immediately grabbing my finger and punching a hole in it using its thick proboscis. The pain was so sharp that I remember falling backwards and landing hard on my buttocks, while the bug let go and escaped. I sat there, silent, holding my hand with a bitter expression on my face.

Maybe I should elaborate at this point. Assassin bugs are venomous animals. Their venom is rather complex and contains many compounds, some of which has neurotoxic properties that can lead to a systemic response (and so potentially may cause death). Some assassin bugs have venom so powerful that it is often compared to a cobra snake’s venom in its potency, easily causing paralysis in mammals much larger than the small bug. Holotrichius inessi, an assassin bug roaming the deserts of Africa and the Middle East is even known to hunt scorpions, which are feisty venomous animals themselves. That is an extreme example. The truth is, in most cases we do not know enough about assassin bugs and their venom potency. So when bitten, you just don’t know what to expect.

Black sand assassin bug (Holotrichius innesi) preying on a scorpion

Black sand assassin bug (Holotrichius innesi) preying on a scorpion

As I sat there trying to gather my thoughts about what has just happened, I felt numbed by the pain. You know how sometimes when something aches so badly you can feel it pulsating? I did not even feel that. I could not feel anything but pain. I thought to myself, this is it. This is how I go. Alex later told me it was the first time he ever saw me looking confused, like I was watching my life flashing before my eyes. To some extent it really felt this way. I could not speak and I did not want to move (from fear I would worsen my condition). I just wanted this to end. We were essentially in the middle of nowhere, with no one around, so we just waited it out. I cannot remember how long it took, as I really lost the sense of time, but I remember the pain eventually reducing to a dull itch. This is when we got up and left. The itch and stiffness stayed for a few additional days and then dissipated.

Just imagine this probe drilling into your finger. Not exactly fun, I can tell you.

Just imagine this probe drilling into your finger. Not exactly fun, I can tell you.

I always find it a bit funny that my worst bug bite actually is a bug bite. Ever since that trip I have been trying to find that species of assassin bug in my subsequent visits to Ecuador, but I always failed. It is slowly turning into my Moby Dick. The important lesson here is: kids, do not go around poking animals you do not know with bare hands. It has taken me a few more bites and stings until this lesson sank in. Nowadays I am much more careful in the field.
… and I still get bitten and stung.

Your personal opinion means nothing to nature

In the past month I have been involved in some pretty interesting conversations surrounding public perception of stinging and biting insects. This is in large part due to a talk I was preparing about medically significant arthropods (more on that in the next post). Some of the civilized discussions ended in surprising way for me, with a few people unfriending or unfollowing me on social media just because they could not understand my point. I am going to try and address the issues I opened by using excerpts from those discussions. I feel like this is going to end up being a ranty post, but I must do it. Feel free to chime in with your thoughts in the comment section – they are most welcome.

Examining a queen European hornet (Vespa crabro) found overwintering under a log.

Examining a queen European hornet (Vespa crabro) found overwintering under a log.

To put it simply, there are two topics I want to open:

1. “Aggressive” arthropods

The first discussion evolved after I shared a conversation I had with a twitter user about a photo of a wasp.
The guy immediately took the stance of “all wasps are aggressive”, and continued to give examples from his own experience of wasps nesting close to his window. I do not want to get into too many details (you can see that conversation in the screen grab), I will just mention that a) the photo showed a male wasp that is incapable of stinging, and b) the nesting wasps do not know they are using this guy’s window. They do not even know what a window is!!!
There seems to be some confusion surrounding the term “aggressive” when describing arthropods, and animals in general. Hippopotamuses are aggressive. Some bears are aggressive. Crows can be aggressive if you injure one of their members. I think you get my point. With arthropods, I am not sure I have a clear cut example of aggressiveness. Maybe “aggressive” is not the right word. Don’t get me wrong, venomous stinging animals are still somewhat dangerous and occasionally do land people in the hospital after being stung. But I ask you, when you call them aggressive, what do you mean exactly? Aggressive to who? Anyone within the range of a nest or just anyone? Do they chase and attack people without provocation? Who took the first step? Sometimes being too close to wasps triggers their defense behavior. But then again, you really have to rub it in their face and disturb them for this alarm response to occur.

Yellowjackets (Vespula germanica) feeding on a fallen pear

Yellowjackets (Vespula germanica) feeding on a fallen pear

For example, I was very close when I took this photo of the yellowjackets. The wasps were active all around me, and NOTHING happened. These wasps were very nice to me. Seriously, I do not understand why they have such a bad reputation. Don’t start nothing, won’t be nothing. I am not saying anyone else should try to do the same. That would be foolish, especially if you are not familiar with wasp behavior. But I would not call them aggressive. I see wasps and other stinging arthropods as “defensive”. I think the difference between aggression and defense is the presence of provocation. If an animal attacks without provocation, I would classify it as aggression. What is debatable is the definition of provocation. Clearly the meaning of it to us is different from that perceived by social insects. Do not forget that in their world chemical communication takes a substantial part. If the wind blows in their direction, carrying over our scent to the nest, that would be considered a provocation and will trigger a defensive behavior. Things are different if you accidentally hit a wasp nest. Then they will “aggressively” defend their nest.

For many people the sight of a hornet nest in their backyard is terrifying. But in reality these wasps are only interested in making it through the summer months.

For many people the sight of a hornet nest in their backyard is terrifying. But in reality these wasps are only interested in making it through the summer months.

Of course, no one can tell what goes on in a wasp’s mind. They cannot read our minds either. They do not know our intentions just as much as we do not know theirs. There has to be some sort of mutual respect if you want this to end peacefully. Unfortunately, that is something that a lot of people do not have towards nature today. People just see ‘wasp’ and go batshit crazy.

I agree that in some areas where they are invasive, wasps are a problem, particularly in islands. They forage on native fauna, spreading fast and wrecking havoc in their path. But is it aggressiveness? Or is it evidence that they are just very good at what they are supposed to do? It is just foraging and nothing more. Because they thrive in areas with no natural enemies, their food hunts may seem like the wasps are out of control, but they are really just doing their thing to survive and reproduce. Still, they need to be eradicated from these habitats, no doubt.

Going back to the meaning of the word “aggressive”, it shows how difficult it is to communicate without having a clear definition of the word. This is more a discussion about semantics than anything else. Now, I am guilty for being stuck in my own bubble with no idea how things are perceived by others. Each person has their own definition of what being aggressive is, and this is in part related to their personal experience as a human. As noted by a friend of mine, this is largely due to the unprovoked aggressiveness we know from human troublemakers and the unnecessarily violent overreaction that happens when someone thinks they took enough beating and lashes back out. I think the first step is to differentiate the use of the term “aggressive” for describing human behavior and animal behavior. Here is why I stopped using the term frequently when discussing animals:
It crates a negative outlook on nature.
We tend to bring our human-centric approach to nature. “Those animals are trying to hurt me”. “They built a nest on my property”. I understand that it is frustrating to discover a potentially injurious animal in one’s living space, if this had happened to me I would want them removed too. But we must learn to put ourselves out of the picture. Those animals are not there because of us. They are there because the harsh competition in nature is forcing them to do what they can to survive. It just so happens that our living space feels safe for them too, but can you blame them?

2. “Purpose” in the natural world

Perhaps one of the questions I get asked the most, even more often than which camera equipment I use, is what is the purpose of –insert pest species here-:
What is the purpose of flies?
What are mosquitoes good for?
What is the purpose of wasps in nature?

I think these questions stem from a very common human behavior. From an early age we have this innate, almost inexplicable urge to ask “why?” about everything. We are curious to break down how things work around us, and if the world is constructed from tiny pieces, then every piece must have its own purpose assigned to it.
The real question here is who assigns these purposes. Is it man? That would be a very anthropocentric view of life. Conversely, if you believe a purpose is assigned from above by an all-powerful being such as god, then you should not be asking an entomologist these questions. You should ask god. (go and do that right now. It’s OK, we’ll wait. Are you back? Good. Let’s continue) In contrast, if we look at the natural world from an evolutionary perspective, then yes, all the pieces have their rightful place in the big puzzle, otherwise they would not exist.

This is why I believe the questions mentioned above are phrased horribly. Using the word “purpose” suggests that there must also be a benefit to us, humans, to justify the existence of something. That is the wrong way to look at the world. This search for purposes, for meaning in everything, is a characteristic of human nature. Well, what is the purpose of humans then? Why are we here? This is not an easy question to answer when you start thinking about it seriously. Because one person may think humans are on this planet for one purpose, while another person will think of a different purpose for our existence. But let’s not get too philosophical and go back to arthropods and other pests.

What is the purpose of flies/mosquitoes/wasps/ticks/leeches?
To survive.
A better way to look at this would be to ask what role those animals play in nature. To this question there is a concrete answer, because every species has its natural history. The pest insects mentioned above break down organic matter, pollinate, and regulate the populations of other arthropods. I want to take this opportunity to give an example for such an inquiry gone totally wrong, and use it to forward the discussion and paint the bigger picture.

Last week I shared a photo of an African tick, Dermacentor rhinocerinus. The only reason I posted it was because I thought it was beautiful, and I wanted to show that it is possible to appreciate such an animal even though I would not want it to suck my blood.
To be honest, I already got used to getting hate comments and I expected some negative responses to arrive. And arrive they did.
Let’s analyze this conversation together.
In this first part of the conversation, a person leaves a comments that ticks are never beautiful, and that their existence has no justification. This a subjective statement, so I reply in the same manner. Then they go on by saying that ticks serve no purpose in the ecosystem, and that nature would be better off without them. This kind of comments makes me cringe. If an organism exists right now as we speak, it means two things: it has a well-based role in nature, and it is extremely good at what it does.
I am copying my reply because I think it is worth reading:

The only thing that ticks do in nature, just like any other animal, is survive. That is the one job they have – to continue the existence of their species. They do so by feeding on blood of other animals. And by doing that (their “role”, if you wish), they dilute and remove the weak individuals from the mammalian population. Now, what is important to understand here, is that ticks do not exist to spread diseases. They are blood feeders. The disease pathogens come from mammals and birds. Ticks have no mutualistic relationships with the bacteria, viruses, and protozoans that they vector. Spreading diseases is more of an artifact of their feeding habits. You want a world without ticks? Fine, but just like you said ecosystems would adapt to their absence, those disease pathogens will continue to thrive in their mammalian hosts, and nature will find a way to get those diseases back into humans.
I’m going to take a risk by saying a world completely free of diseases is a world without life.

The next part is really interesting. After explaining that ticks belong in the natural world no less than other animals (as well as humans), the person who started the conversation goes back to their original stance. Suddenly they remember that they already know and understand everything that has been discussed so far, but they insist that ticks cannot be referred to as beautiful. It is blasphemy. What I find amazing is that this person accused me of having a naïve perspective of biology because I thought a tick was beautiful. This is coming from a person who spent much of his time breeding killifishes, a hobby fish that is praised and prized for its beauty. Oh, the irony.

Conclusion

What these two topics have in common is showing that people tend to bring a lot of their emotions into the conversation when they talk about arthropods they hate. I understand that you do not like insects and arachnids. I also understand that you feel like they are chasing you. However, please trust me when I say there is absolutely no stinging arthropod that is out to get you. They use their stinger for defense only. If you do feel like something is coming after you, please consult a physician or a psychiatrist – you might suffer from delusional parasitosis, entomophobia, or arachnophibia (all totally normal, and treatable by the way!). Also please be aware that there are people out there who find these creatures fascinating and beautiful, even pest insects like mosquitoes. If they can do it, maybe these bugs are not so bad after all? Give them a chance. You may find that the fear and hate you experience are only a manifestation of not knowing enough about these animals. And at the very least, be respectful and compassionate to other people, even if they hold a different opinion than yours.
At the end of the day, your personal opinion means nothing to nature. Nature will continue to function regardless of what you feel. You know what does mean a lot to nature? Your actions.

 

Little Transformers: Myrmarachne formicaria

Little Transformers is back! And this time our star is a small jumping spider that goes out of its way to masquerade as an ant.

I am often accused for not writing about topics related to Canada on this blog. While this is not entirely true, I could have without doubt posted more about local critters. It is a great time to do so now, as I will be taking the opportunity to address several events.
Firstly, it is now October, and we are getting closer and closer to Halloween (Oct 31st). Nine years ago, the Arachtober initiative was born: why wait till the end of the month to celebrate spiders? Let’s celebrate them and other arachnids throughout the entire month of October! And so, during the month of October we give arachnids more exposure in hopes to educate the general public about these magnificent and important creatures.
Secondly, a new initiative is slowly forming, International Jumping Spider Day, on October 10th. The idea is to use the easily adored jumping spiders as the gateway arachnid for changing the often-negative public perception of spiders. I wholeheartedly support this idea and hope to see it catching on.
Lastly, a shameless plug: You may have noticed that this blog is nominated for the 2017 People’s Choice Awards: Canada’s Favourite Science Online. It is a huge honor to be included with other excellent science blogs and sites on the same list. If you like the content and stories that I post, you can show your appreciation by voting following this link. I wish to thank those who already voted in support of this blog. While this nomination has nothing to do with spiders, I thought it is a great opportunity to write a blog post about an arthropod found in Canada.

Female ant-mimicking jumping spider (Myrmarachne formicaria) wants your attention

Female ant-mimicking jumping spider (Myrmarachne formicaria) wants your attention

After this short introduction, it is time to present our first local Little Transformer, the ant-mimicking jumping spider Myrmarachne formicaria. It is one of the nicest looking spiders here in Ontario, and it is surprisingly abundant in its habitat. Alas, there is a small catch here. While this jumping spider is local, it is not native to Canada. This species was first detected in North America in 2001, and later established in Tommy Thompson Park in Toronto in 2015. It originates in the Palearctic region, more specifically Europe and Asia. Despite this, these spiders feel right at home in Toronto, as it seems that they are spreading away from the park containing the main population. This year, Sean McCann recorded Myrmarachne in Scarborough (east Toronto), and I found them in Mississauga (west of Toronto).

Female ant-mimicking jumping spider (Myrmarachne formicaria) masquerading as an ant

Female ant-mimicking jumping spider (Myrmarachne formicaria) masquerading as an ant

Myrmarachne formicaria is an elongated jumping spider that takes the appearance of a small ant, and here in Ontario it is associated with the European fire ant, Myrmica rubra, also an introduced species. Isn’t it interesting how these two non-native species managed to find each other on unfamiliar land? The spider has long and slender legs just like those of an ant, and the banded forelegs are slightly thicker to resemble antennae. The cephalothorax has a depression to echo the segmentation in ants separating head from thorax. The abdomen is long with a narrow connection to the cephalothorax, reminiscent of an ant’s petiole. Surprisingly, in this species the pedipalps (normally a distinguishing character between males and females) are swollen in females, a trait usually seen only in males. Males on the other hand have enormous toothed chelicerae that stick right out of their faces. I suspected this is a sexually selected trait used in fights for females, and this was later confirmed by Sean McCann (check out his amazing shots here).

Female ant-mimicking jumping spiders (Myrmarachne formicaria) have swollen pedipalps

Female ant-mimicking jumping spiders (Myrmarachne formicaria) have swollen pedipalps

Male duck-mimicking jumping spide... um, excuse me ANT-mimicking jumping spider. Quack quack.

Male duck-mimicking jumping spide… um, excuse me ANT-mimicking jumping spider. Quack quack.

This begs the question, why do Myrmarachne spiders look like ants? Do the spiders use their appearance to fool the ants into thinking they are members of their own colony in order to sneak up on them and prey on ant workers or larvae? Not really. For starters, the ant species approached by Myrmarachne formicaria are usually not visual creatures. They rely more on their chemical communication, using volatile pheromones, for navigation and recognition. Moreover, the spiders seem to deliberately avoid any contact with the ant workers. They may walk among the ants, but they always keep their distance from them. In fact, when I experimented and isolated a few spiders within a group of ants, the spiders chose to stay still, and only when the path was clear they made a run for it. I also noticed that the ants display an aggressive response when encountering a spider. So the ants are not the target of this mimicry. Who is? Us. Or more precisely, predators. You see, the spider not only looks like an ant and spend its time close to the ants, it also moves like an ant.

Myrmarachne formicaria always keep a safe distance from Myrmica rubra workers

Myrmarachne formicaria always keep a safe distance from Myrmica rubra workers

A recent study looked into the locomotion of Myrmarachne formicaria jumping spiders and found that they do not move like their peers. First of all, instead of jumping like most salticid spiders, they move forward in a series of short sprints. But they also move in a pattern that resembles the movement of ants following a pheromone trail, back and forth in a winding wave motion, instead of random strolling and stopping often we see in other spiders. If it looks like an ant and moves like an ant… it might be good enough to fool predators that it is an ant. And I can attest to this – it is extremely difficult to keep track of a Myrmarachne spider moving about in an area with ant activity. Look away, and you will need all the luck in the world to find it again. The spiders also benefit from being close to a colony of highly defensive ants. Myrmica rubra is easily alarmed and has its reputation when it comes to stinging intruders.

Some Myrmarachne formicaria feature a two-colored cephalothorax, to emphasize the part that mimics the ant's head

Some Myrmarachne formicaria feature a two-colored cephalothorax, to emphasize the part that mimics the ant’s head

If they do not hunt the ants, what do these spiders feed on? They seem to go after soft-bodied insects, and they are especially fond of dipterans: small flies, mosquitoes, midges etc’.

Male ant-mimicking jumping spider (Myrmarachne formicaria) feeding on a chironomid midge

Male ant-mimicking jumping spider (Myrmarachne formicaria) feeding on a chironomid midge

A closer look at the feeding Myrmarachne male reveals the weaponized chelicerae, used in fighting other males

A closer look at the feeding Myrmarachne male reveals the weaponized chelicerae, used in fighting other males

At this point you might ask yourself why I included this jumping spider in my Little Transformers series. Sure, it mimics an ant, but that’s it. Or is it? In order to qualify as a Little Transformer the arthropod needs to change something in its appearance to transform into something different. So far we have seen that these spiders move in an atypical fashion to jumping spiders. But there is one more thing they do to conceal their salticid identity. What is the one, fail-safe characteristic of jumping spiders? Those huge front eyes! If only the spider could hide them, it would look like the perfect ant. And they do exactly that.

I look at this spider and I see an ant staring back at me.

I look at this spider and I see an ant staring back at me.

Myrmarachne often wave their forelegs in the air to mimic the ants’ antennae, but the legs also hide their most recognizable feature, the bulging front eyes. Females seem to do a better job at this than males, transforming into ants right before our eyes.

Male ant-mimicking jumping spider (Myrmarachne formicaria). Even on a side-view I still see a weird duck...

Male ant-mimicking jumping spider (Myrmarachne formicaria). Even on a side-view I still see a weird duck…

What is most intriguing here is that the rear pair of eyes evolved to be very large, bearing a striking resemblance in their size and position to ant eyes.

Ant-mimicry is quite common among arthropds, and many species of jumping spiders deploy this strategy as an anti-predator defense or to assist in foraging. While some do not consider Myrmarachne formicaria as a case of perfect mimicry, it is a gorgeous spider with intriguing behavior. Besides, mimicry does not have to be perfect to satisfy our aesthetic desires. It only has to be good enough to benefit the spider’s survival.

Compsus: glitter weevils with structural coloration

The insect world is full of great examples for flamboyant insects. From mosquitoes sporting feathery legs and electric blue scales, through the splash of vibrant colors in rainbow katydids, to shiny golden-green orchid bees and their mimics. But none are as dazzling as the glitter weevils of genus Compsus (family Curculionidae, subfamily Entiminae).

Short-snout weevil (Compsus sp.) from Mindo, Ecuador. It is hard to take all these colors in.

Short-snout weevil (Compsus sp.) from Mindo, Ecuador. It is hard to take all these colors in.

Compsus is a large genus distributed mainly in Central and South America, with one species occurring in North America. It contains around 140 species, mostly small to medium sized beetles of 0.5-2.5cm in length. Several species are considered as pests of citrus trees. The adult weevils feed on plant tissue: leaves, flower petals, and pollen, but they will also go for rotting leaves and fermenting fruits. The females oviposit egg masses on the aerial parts of trees. The young legless larvae hatch, drop to the ground, and burrow into the soil where they feed on the roots of the tree. At the end of its developmental stage the larva builds a chamber in the ground and pupates, and it will stay in this state for two months until the adult’s eclosion. Compsus weevils complete their life cycle within 5-7 months.

Another species of Compsus from Mindo, this one has a bit more metallic sheen to it.

Another species of Compsus from Mindo, this one has a bit more metallic sheen to it.

Compsus weevil feeding on rotting plant tissue

Compsus weevil feeding on rotting plant tissue

Freshly-eclosed short-snout weevil (Compsus sp.) use impressive mandibles to break out of the pupal skin. These scissor-like attachments drop later.

Freshly-eclosed short-snout weevil (Compsus sp.) use impressive mandibles to break out of the pupal skin. These scissor-like attachments drop later.

But what makes Compsus weevils so special, as well as other members of subfamily Entiminae, is their eye-catching colors. I would do these beetles a disservice if I didn’t explain where the colors come from, so things are about to get technical. Animal coloration is derived from spectrally selective light reflections on the outer body parts. There are two types of coloration:
1) Pigmentary (or chemical) coloration – occurs when pigments absorb scattered light in a narrow wavelength range. This type of coloration is the most common in animals.
2) Structural (or physical) coloration – achieved by nanometer-sized structures with changing refractive indices, causing coherent light scattering. Structural coloration is less common in the animal kingdom but it is widely encountered as well, and often structural colors are modified by spectrally filtering pigments.

Scales containing photonic crystals on the head of a Compsus weevil

Scales containing photonic crystals on the head of a Compsus weevil

Scales containing photonic crystals on the body surface of a Compsus weevil

Scales containing photonic crystals on the body surface of a Compsus weevil

The structures causing the physical colors are referred to as photonic crystals if they have properties (periodicity) that align with wavelengths of visible light. One-dimensional photonic crystals consist of parallel thin film layers of alternating high and low refractive index materials. These structures create the metallic and polarized reflections of cephalopods skin, the elytra of jewel beetles and scarabs, and the breast feathers of birds of paradise. Two-dimensional photonic crystals are structures with periodicity in two dimensions. An example for two-dimensional photonic crystals in animals would be the coloration of peacock feathers. Three-dimensional photonic crystals have been found in the scales of weevils and other beetles, but also in butterflies like the blue morpho.

Scales containing photonic crystals on the body surface of an Entiminae weevil (Eupholus schoenherri) from Indonesia

Scales containing photonic crystals on the body surface of an Entiminae weevil (Eupholus schoenherri) from Indonesia

Scales containing photonic crystals on the body surface of an Entiminae weevil (Eupholus schoenherri) from Indonesia

Scales containing photonic crystals on the body surface of an Entiminae weevil (Eupholus schoenherri) from Indonesia

Scales containing photonic crystals on the body surface of a Compsus weevil

Scales containing photonic crystals on the body surface of a Compsus weevil

Blue scales on the leg tarsus of an Entiminae weevil (Eupholus linnei) from Indonesia

Blue scales on the leg tarsus of an Entiminae weevil (Eupholus linnei) from Indonesia

In the case of Entiminae weevils, the adult beetles have strikingly iridescent scales, sometimes immersed in pits on the weevils’ elytra and legs. This gives the weevils a festive glittery look, as if they were covered with confetti during a big party. The reason for the bright coloration in weevils is mostly misunderstood. In some ways it may serve as camouflage in green species, but blue-colored species are very conspicuous so it remains unclear whether they advertise something to potential predators. I cannot complain: for me it is always a joy to see the cute Compsus weevils in the wild, even though sometimes it makes you feel like you missed out on a celebration or something.

 

Public outreach: Promoting the appreciation of arthropods

Last weekend I had the pleasure of taking part in an outreach event, Guelph Bug Day, at the University of Guelph Arboretum. Bug days are public events, usually free of any admission fees, which promote the appreciation and admiration of insects and arachnids, and set out to educate anyone who is fascinated by arthropods.
This is not the first time I participate in such an event. Last year I presented arachnids at Bug Day Ottawa. In fact, ever since I became interested in insects and their natural history, I have been involved in presenting them to whoever was interested: I brought live insects to lab sessions in high school, I led my mates in outdoor excursions to find spiders and scorpions during my military service, I collaborated with operating museums and insectariums as a consultant on exhibitions, and I incorporated the use of live insects in biology studies at universities to help students gain a better understanding of the courses material. More recently though, I have been more active in events aimed at the general public, in order to bring arthropods into the mainstream and help people overcome their fears. And so far, it has been a blast. Take this recent bug day in Guelph for example: I found myself smiling from ear to ear the whole time, and my table was always busy with no moment to rest, not that I am complaining. This was the first time Guelph holds a bug day event and to be honest, it was the best one I have ever been to. It was that good. But before I talk about the bug day, let me elaborate a little about public outreach and why I think it is important.

When working in science, especially when you acquire some expertise, it becomes difficult to expose the public to your subject of research and communicate about it. The more knowledge you gain about your study system, the harder it gets to explain it to people with little or no science background and get them to care about it. I am happy to say that this is changing thanks to the engagement of researchers and science communicators with the public on social media. Yet there is still a long way to go.

More specifically, nowadays most people go about their daily lives with little or no exposure to the wonders of nature. I once brought velvet worms to a public outreach event at the Toronto Zoo and the response was phenomenal. It was not surprising – the majority of people, biologists included, will live through their lives without even knowing these majestic animals exist, let alone see a live one. So in my opinion this exposure is critical, it can influence the public’s opinion and later have implications for nature conservation. I do think people should familiarize themselves with whatever is found in their area, both plants and animals. After all, insects and spiders are everywhere, and most of them are not out to get anyone. They are harmless and usually mind their own business.

When I present live arthropods, I love interacting with children and let them handle the animals, but I am even more interested in getting the parents into the game. You see, the reality is that the majority of kids already like bugs. They are curious about the diverse world of invertebrates, those common animals that are so different from mammals and birds, and have the appearance of small toys. Unfortunately, at some point children lose their interest in invertebrates, and sometimes even worse, replace it with fear and hate. It is difficult to pinpoint exactly when and why that stage occurs. But it is most likely due to an environmental influence – succumbing to peer-pressure from friends or parents, and witnessing a shift in cultural appreciation as technology takes nature’s place. Parents have a huge role in preserving the view of the natural world in young people’s minds by encouraging them and nurturing their curiosity. Many times I have seen an excited kid holding an insect turn to their parents in hopes for affirmation. However, sometimes the kids are uninterested in insects, in which case I try to work directly with the parents and get them to handle the animals. Some children just need to see their parents doing something a bit unconventional to get confirmation that they are cool!

It just so happens that I stumbled upon this beautiful artwork by Tiana Cabana, a lovely composite image (inspired by another artwork) depicting my burning passion and mission –

Give small critters some room in your heart. Embrace them.
It will make you a better person, and they will appreciate it too.

Going back to Guelph Bug Day, I was astonished by the sheer amount of positivity expressed by the visitors attending. Even those who confessed their fears gave the arachnids a chance after listening to some facts about them and realizing that they do not pose a threat. I find this level of open-mindness incredible, and it is in great part thanks to the amazing organizers and volunteers who put so much of their energy into making this event a reality. Such a talented group of people.

I returned home from the bug day with such a “high”, almost intoxicated, feeling. At first I didn’t know what it was. Sure, the event was fun, but was it that fun? What is this smile smeared all over my face? Why am I so restless, why can’t I just sit down? And it finally dawned on me what it is that I was feeling. It was love. I was in love.
So yeah, I can get pretty emotional at times, but the important take home message for me here is that I can see myself doing this every single day, for the rest of my life. Thank you, Guelph Bug Day. You have a special place in my heart.

One lesson learned from doing these events – I need to bring a camera…

The discovery of Charinus israelensis, a new whip spider from Israel

When I was a kid I used to spend hours in the Israeli outdoors, looking for insects and arachnids in hopes to familiarize myself with as many arthropod species as possible. I was so darn good at finding small critters that soon enough friends requested to tag along to see what I could unearth during a short afternoon hike. My parents recognized my growing passion and got me the natural history “bible” at that time – the 12 volumes of Plants and Animals of the Land of Israel: An Illustrated Encyclopedia. I studied it carefully, trying to set goals to find certain species, which led me on excursions throughout the country. Yet one arachnid seemed to remain out of reach.

Charinus israelensis, a new species of whip spider in Israel

Charinus israelensis, a new species of whip spider in Israel

It looked like a cross between a mantis and a spider, with one long pair of appendages. It was an amblypygid, a whip spider. The book listed only a single species occurring in Israel, Charinus ioanniticus, very rare. It featured a tiny photo, followed by a large illustration on the opposite page, a replication of the photo. In the days before the internet, that was my only reference for this arachnid group.

Amblypygi in: Plants and Animals of the Land of Israel: An Illustrated Encyclopedia

Amblypygi in: Plants and Animals of the Land of Israel: An Illustrated Encyclopedia, Vol. 2 Arachnids. For nearly a decade this was my only reference for information about whip spiders.

I was determined to see a live one, but I always failed to find them. I kept looking at those pages in hopes to memorize every aspect of the animal, making sure I can confirm its identity in case I stumble upon one. Years have passed and I gave up on finding one in the wild. I did get a chance to see a live specimen during my high school days though, in one of the visits I paid to Pinchas “Pini” Amitai, the man who took the original photo in the book. Little did I know that 20 years into the future I would be involved in discovering a new species of whip spider living in Israel.

This discovery is not recent news. We found the new species over five years ago, and the formal description was published last year. The media intended to feature the story, but unfortunately a former president in Israel passed away on the same week the paper was published and there was no interest in a story about an obscure arachnid living inside caves in Israel. Despite that, I waited. The discovery is an important one, and I was hoping our new species could still make an appearance in the news. And as you can imagine, I am still waiting. Well, as the old saying goes – if you want something done, you have to do it yourself.

So let me tell you the story of this cute arachnid. Back in 2012 I stumbled upon a photo of a whip spider from Israel in one of my social media newsfeeds. The photo was taken by Dr. Eran Levin during a cave survey for his research about bats’ hibernation sites. Since I had an approaching trip to Israel I contacted my friend and asked if he would share the location, because I was still hoping to see and document a wild whip spider in my home country. We chatted for a while, the location was a bit unexpected for amblypygids in the area, but a few months later I found myself crawling through a tight opening into the warm cave. And indeed they were there, happily roaming on the walls, waving their magnificent long legs everywhere.

A juvenile of Charinus israelensis walking on the wall in one of the caves

A juvenile of Charinus israelensis walking on the wall in one of the caves

Molts hanging from the cave's ceiling are a good sign for an active whip spider population.

Molts hanging from the cave’s ceiling are a good sign for an active whip spider population.

Charinus israelensis cleaning its leg

Charinus israelensis cleaning its leg. This specimen lost two of its legs in fights with others (see example below). They will grow back the next time it molts.

I took some photos and happily went home. When I inspected the photos later, something did not sit right with me. I still had a vivid memory of the photo and illustration in the book from my childhood. But now, I could also use information online for confirmation. The amblypygid species known from Israel, Charinus ioanniticus, has well developed median eyes. It almost looks like it is crossed-eyed. How cute.

Charinus ioanniticus' big smile. See the tiny beady eyes? Adorable!

Charinus ioanniticus’ big smile. See the tiny beady eyes? Adorable!

I looked at my photos, and none of the animals had median eyes. What is going on here?

Charinus israelensis, note the absence of median eyes

Charinus israelensis, note the absence of median eyes

Charinus israelensis can have big smiles too

Charinus israelensis can have big smiles too

In all other visible aspects the whip spiders looked like C. ioanniticus, yet the absence of eyes was enough for me to suspect that I might be dealing with a new species. I made some calls, went back to collect some specimens, and started the long process of verifying and describing the species with colleagues (you can find our paper on my publications page). I invested my energy and personal funds into that research. For me it was a mission to put the spotlight on this exciting new find. We named it Charinus israelensis. I became heavily involved with the general public and posted requests in forums and social media groups for any records or sightings of whip spiders in Israel. Slowly but surely, I started receiving responses from various people located throughout the country. Some of which mentioned whip spiders that found their way into homes, others were reported from natural caverns. It was even more interesting to visit some of those places with the people who made the sightings, and witness the whip spiders’ populations together with them. I learned a lot about caves in Israel, and how much we still don’t know about these habitat systems. But the best experience for me while searching for the new species C. israelensis was to discover new unrecorded populations of the known species, C. ioanniticus. And more than anything, I suddenly realized that they are not at all that rare as mentioned in the old encyclopedia. They are just extremely cryptic, remaining hidden in tight crevices and coming out in the darkest of nights. No wonder people never see them.

Charinus ioanniticus from a newly recorded population in the Carmel Mountain Ridge of Israel

Charinus ioanniticus from a newly recorded population in the Carmel Mountain Ridge of Israel

Why is this exciting? There are two main reasons. The first one is that this discovery doubles the Amblypygi fauna for Israel. It may not sound much, but jumping from one species to two is actually a big deal. It has implications on our understanding of food webs in caves, and these unique arachnids may give further incentives to protect and conserve cave habitats in Israel. The second reason is that the loss of eyes in cave animals (troglomorphism, a term associated with adaptation for life in dark caves) is an interesting topic for studying the evolution of traits within a phyllogenetic lineage. There are already several examples of blind Charinus whip spiders from around the globe, which may lead to fascinating research in the future. In the meantime, I continue to keep live specimens of both Charinus species from Israel, learning a ton about their biology in the process.

A freshly molted Charinus israelensis shows spectacular coloration

A freshly molted Charinus israelensis shows spectacular coloration. The color turns reddish-brown after some time.

Two females of Charinus israelensis fighting

Two females of Charinus israelensis fighting. Whip spiders have complex communication based on movements of their antenniform legs. Some encounters turn hostile, in this case because the bottom female was gravid.

Charinus israelensis female carrying an egg sac

Charinus israelensis female carrying an egg sac

Some of the adult whip spiders that were collected in the beginning of the research are still alive and kicking! Quite impressive for a small arachnid, and seems like they can even outlive some of the more “conventional” pets.

Because I eat, sleep, and breathe whip spiders, my friend Peggy Muddles aka The Vexed Muddler made this awesome portrait of mine with C. israelensis (check out more of her fabulous stuff here)

artwork by Peggy Muddles

“Whip spiders are the coolest arachnids that will never hurt you”

By the way, this weekend (Sunday August 27th, 10am-5pm) the University of Guelph is holding a “Bug Day” at the Arboretum Centre. Come for a fun day out and learn about arthropods. I will have a table with whip spiders, so please drop by and say hi. I will also have some framed whip spider molts with me so please come and check them out!

Jumping spider mimicry in Brenthia moths

Many insects deploy mimicry to fool their predators into thinking they are highly defensive, venomous, or simply not to be messed with. A great fraction of mimicry cases involve adopting the appearance of ants, wasps, and spiders for these exact reasons. One of the most interesting cases, however, is predator mimicry: insects that take the appearance of their potential predators in order to expose them. I have already written about one such case in crambid moths, but in this post I want to present one of the classic examples for this mimicry in metalmark moths of the genus Brenthia.

At first glance, metalmark moths do not really resemble spiders. In my post about Petrophila moths I mentioned that observed spider mimicry might also be a case of pareidolia. In other words, we as humans seek familiar patterns surrounding us, so we recognize the image of a spider on the wings, but is it really mimicry? And indeed, after posting I was accused of having a strong imagination for thinking this is mimicry. There is a good point being made here – in the case of Petrophila there is a temporal barrier preventing the two from encountering each other under normal conditions. Petrophila moths are nocturnal while jumping spiders are diurnal. Nevertheless, the prevalence of such wing patterns in the insect world suggests that they have a role in the survival of those organisms.

Metalmark moth (Brenthia hexaselena) displaying its typical body posture, with wings raised like a peacock's tail.

Metalmark moth (Brenthia hexaselena) displaying its typical body posture, with wings raised like a peacock’s tail.

Brenthia moths are no different. It takes some imagination to strip them off their mothy characteristics to see the resemblance to jumping spiders. Members of family Choreutidae, the genus contains over 80 described species, all sharing the same appearance: a unique body posture, and wings patterns that are reminiscent of jumping spiders’ eyes. In fact their common name, metalmark moths, is due to the convincing “catchlight” area of the eyespots, often consisting of silvery scales. Brenthia species also move like jumping spiders, advancing by short bursts of movements while still retaining their wing display. Lastly, these moths are diurnal and can be seen active on top of leaves, just like salticid spiders. If you think it ends there for these moths in regards to anti-predator defenses, let me also add that their caterpillars deploy defense strategies as well. When alarmed, they launch themselves through holes chewed into the floor of their webbed feeding shelter, giving the term “teleporting through a wormhole” a new meaning.

Metalmark moth (Brenthia hexaselena) in frontal view, displaying wing patterns that resemble a jumping spider's face and legs.

Metalmark moth (Brenthia hexaselena) in frontal view, displaying wing patterns that resemble a jumping spider’s face and legs.

Brenthia moth (upper image) mimics jumping spiders (lower image) with wing markings, wing positioning, and posture. Figure from Rota and Wagner 2006 (drawing by Virginia Wagner).

Brenthia moth (upper image) mimics jumping spiders (lower image) with wing markings, wing positioning, and posture. Figure from Rota and Wagner 2006 (drawing by Virginia Wagner).

Portrait of a jumping spider (Phiale formosa). It is a little difficult to see the resemblance to the moth's wing patterns, but the important thing is that it works to the moth's benefit.

Portrait of a jumping spider (Phiale formosa). It is a little difficult to see the resemblance to the moth’s wing patterns, but the important thing is that it works to the moth’s benefit.

When discussing animals mimicking their predator, it is important to remember that we humans are not the target audience. This means that the imitator may not look too convincing in its mimicry to us, but still manages to trigger a desired response from said predator. However, when in doubt, the best way to know for sure is to put the suggested mimicry to the test through a series of experiments. Brenthia moths have become one of the best examples of spider-mimicking moths, thanks to rigorous testing. In their classic paper, Rota and Wagner placed the moths with their potential predators, jumping spiders of the species Phiale formosa, in arenas and recorded the outcome. They also used non-mimicking moths of the same size as control for the experiments. The results showed that the jumping spiders respond to Brenthia by displaying territorial behavior and waving their forelegs. In other words, upon noticing the Brenthia moths the spider predators immediately expose themselves. It comes as no surprise that Brenthia moths had a high survival rate in the experiments, as they could take off once the danger was revealed, avoiding predation. The control moths did not trigger a territorial response from the spiders and were preyed upon extensively.

Jumping spider (Phiale formosa) displaying territorial behavior in response to its own image. This is when the moth knows it is in danger.

Jumping spider (Phiale formosa) displaying territorial behavior in response to its own image. This is when the moth knows it is in danger.

One thing to keep in mind though is that this mimicry works well only because salticids are special among spiders. They do not make a web to capture prey, but instead rely on their excellent vision to detect prey. They are active predators, and therefore display a wide array of behaviors to communicate with other salticids. Jumping spiders will avoid other jumping spiders due to the risk of cannibalism. Brenthia moths take advantage of this behavior to get the higher ground by delaying the spider’s attack in order to escape. This makes them one of nature’s greatest con artists, but when survival is on the line, anything is kosher.

Papers mentioned in this post:

  • Rota, J, Wagner DL (2008) Wormholes, sensory nets and hypertrophied tactile setae: the extraordinary defence strategies of Brenthia caterpillars. Animal Behaviour 76(5): 1709-1713
  • Rota J, Wagner DL (2006) Predator Mimicry: Metalmark Moths Mimic Their Jumping Spider Predators. PLoS ONE 1(1): e45. https://doi.org/10.1371/journal.pone.0000045

Little Transformers: Dysodius

When I first came up with the idea of Little Transformers, what I had in mind were insects that can masquerade as other objects by changing their appearance or behavior. I consider myself a “mild” Transformers fan: I like the concept of entities taking the form of other things, very much like how mimicry or camouflage work in nature. I have said before that I am not a fan of the current iteration of Transformers, those movies are so bad. However, I am going to take advantage of the upcoming release of the new Transformers movie (and I cannot believe I am using this as my reasoning) to post about yet another Little Transformer. This one does not really transform though, but it sure looks like one of the robots in those films. While I am not sure who is behind the designs for the robots, it was clear right from the start that there is some insectoid perspective to their appearance. I have always preferred the simple “blocky” design of the original cartoon show, but I can see how that would not look very realistic.

As mentioned above, our Little Transformer may not pass as the best example for a mode-changer, but it has an alien-like appearance. Meet Dysodius, a bark bug that belongs to the family of flatbugs, Aradidae.

Bark bug (Dysodius lunatus) crawling on a fallen log. Amazon Basin, Ecuador

Bark bug (Dysodius lunatus) crawling on a fallen log. Amazon Basin, Ecuador

Aradidae are cryptic insects, spending most of their time hidden on or under bark, and inside fallen logs. They feed on fungi: at nighttime both adults and nymphs can be seen aggregating near fruit bodies of mushrooms, sticking their proboscis into the soft flesh. It is a fungi cocktail party, and everyone is invited! Some species of Aradidae even display parental care and protect their offspring. Aradids are incredibly flat, a character that helps them to squeeze into tight crevices and take advantage of the complex habitat that is the bark’s surface, in order to remain hidden from the ever-searching eyes of predators.

Lateral view of a bark bug (Dysodius lunatus). So flat it could sit comfortably inside a paper envelope.

Lateral view of a bark bug (Dysodius lunatus). So flat it could sit comfortably inside a paper envelope.

Members of genus Dysodius are particularly interesting because of the their unique body structure, featuring curved lobes protruding from the pronotum and a crown of “fins” surrounding their abdominal segments. They also have tiny wings, so tiny that it makes me wonder if these wings are truly functional and can create enough force to lift the insect off the ground.

Bark bug (Dysodius lunatus), dorsal view

Bark bug (Dysodius lunatus), dorsal view

Dysodius are also very slow animals. They usually rely on their excellent camouflage rather than speed to avoid threats.

Bark bug (Dysodius lunatus) camouflaged on a fallen log

Bark bug (Dysodius lunatus) camouflaged on a fallen log

Their body surface is rough and often mottled with moss-like splotches. It is also wettable just like tree bark, in other words the colors get darker when getting wet by rain (unlike the water-repellent integument of other bugs), ensuring that the insect is still camouflaged even in rainy conditions.

Bark bugs (Dysodius spp.) from Belize (left) and Ecuador (right) demonstrating different coloration and textures of the body surface.

Bark bugs (Dysodius spp.) from Belize (left) and Ecuador (right) demonstrating different coloration and textures of the body surface.

This begs the question why am I including Dysodius in the Little Transformers series? After all, these insects are already “transformed” and do not change their appearance any further. They already look like a piece of bark. To understand why they are mentioned within these posts, you need to view them from the underside.

Bark bug (Dysodius lunatus), facial view. Am I the only one seeing a robot here?

Bark bug (Dysodius lunatus), facial view. Am I the only one seeing a robot here?

Aradidae, and Dysodius in particular, have one of the most robotic faces in the entire insect world, a face that could easily fit in the current Transformers movie franchise.
If you are not convinced yet, here is a closer look.

Portrait of a bark bug (Dysodius lunatus)

Portrait of a bark bug (Dysodius lunatus)

So if you think the Transformers movies are cool, insects do it better and have been doing it for far longer time. How does that quote from the trailer go?

“A thousand years we’ve kept it hidden. The secret history of Transformers…”

It was hidden all right. But not anymore. I am slowly unearthing this secret, exposing the existence of Transformers right here under our nose. You’re welcome.