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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!

New species of Charinus in Belize

I am happy to announce that our new paper, describing two new species of whip spiders (Amblypygi) from Belize, was recently published (the paper can be downloaded here). This culminates work that started in 2013, in collaboration with Gustavo Miranda and Alessandro Giupponi.

Charinus reddelli from Waterfall Cave, Cayo District, Belize

Charinus reddelli from Waterfall Cave, Cayo District, Belize

The new species were found during the BugShot Belize workshop at Caves Branch Jungle Lodge and its surroundings. The smaller species of the two, now named Charinus belizensis, was discovered under a fallen log during a night hike, concealed inside the decomposing wood and sharing the space with Diplocentrus maya scorpions and platydesmid millepedes. The second species was found within several nearby cave systems, hiding under stones and running on the sandy bottom of the cave. As soon as I found these whip spiders I knew I had something that probably no one has seen before. These were new, undescribed species. Charinus species have been described from almost every continent, they are well-recorded in South America, but so far no species have been described from Central America. Only two reports mention presence of the genus Charinus in Central America: one report from Panama mentions an epigean species with well-developed eyes. I knew the Charinus that I found were different species due to their “blindness” – the two new species have no median eyes, an adaptation for life in closed dark spaces, such as caves and deep crevices. The other report from 1982 is by James Reddell, mentioning a whip spider “troglobite of uncertain generic affinities” in the Footprint Cave in Belize, probably the same species that I found in the very same cave, three decades later. We therefore decided to pay tribute to James Reddell for this discovery and for his enormous contribution to the study of the arachnids by naming this new species after him: Charinus reddelli.

The entrance to Waterfall Cave, where specimens of the new species C. reddelli have been found.

The entrance to Waterfall Cave, where specimens of the new species C. reddelli have been found.

Charinus reddelli, a freshly molted specimen besides its molt in Waterfall Cave

Charinus reddelli, a freshly molted specimen besides its molt in Waterfall Cave

It is not surprising that these species have not received any attention up until now. To begin with, they are very small. The leg span of the bigger species, C. reddelli, is just over 2.5cm. They constantly take shelter inside decomposing wood (C. belizensis) or in rock crevices in caves (C. reddelli). Also, to the untrained eye they may appear as juveniles of the much bigger Amblypygi genera found in the same area, Paraphrynus and Phrynus. As such small arachnids, one might wonder what they feed on. It is possible that C. belizensis feeds on termites and other soft arthropods found inside the wood cavity, whereas C. reddelli was observed feeding on cave crickets nymphs and was even spotted taking down another arachnid – a cave schizomid. Moreover, the live specimens that I keep in captivity have been found to be very fond of eating isopods, so it is possible that they are an important component in these species’ diet. Another interesting observation relates to their breeding strategy. Whip spider females are excellent mothers and demonstrate a high level of maternal care, carrying and protecting the eggs and then later carrying the hatched babies for a while until they can fend for themselves. As small-sized arachnids, Charinus species confront a problem. If they go the same path as the other whip spider genera, producing several dozens of tiny offsprings, then they might run into survival challenges, as the tiny babies must track down and hunt for even smaller prey, and at the same time deal with predators. Instead, C. reddelli‘s egg sac contains only 4–10 eggs, and the hatching whip spider babies are quite large. This ensures that the offspring have a slightly better start in life as they can exploit the common prey size in their surroundings.

Whip spiders females are good mothers and Charinus reddelli is no exception. Here, a female carrying her newborn baby on her back. Three other babies are still in the process of hatching under the mother's abdomen.

Whip spiders females are good mothers and Charinus reddelli is no exception. Here, a female carrying her newborn baby on her back. Three other babies are still in the process of hatching under the mother’s abdomen.

Charinus belizensis fresh after molting before pigmentation appears. Found under a fallen log in Caves Branch forest.

Charinus belizensis fresh after molting before pigmentation appears. Found under a fallen log in Caves Branch forest.

It took a long process to obtain the proper permits, collect, export, and describe the new species, in which I received tremendous help from Ella Baron from Caves Branch Jungle Lodge. The important thing is that now these two small arachnids are known, they have a name and a valid presence, which will make it easier to protect them and their habitat. I hope that in the near future more species of Charinus will be discovered in Central America, filling the gap in their known distribution.

Good times to celebrate the diversity of Amblypygi

For as long as I can remember, I have been fascinated by arachnids. Their high diversity, which includes a variety of morphological and behavioral adaptations, is impressive. It might be surprising though that my favorite arachnid group is not spiders, but a relatively small and not-so-diverse order: whip spiders (Amblypygi).

Juvenile Heterophrynus batesii from the Amazon rainforest in Ecuador. The bright coloration and cute proportions fade as the amblypygid grows older.

Juvenile Heterophrynus batesii from the Amazon rainforest in Ecuador. The bright coloration and cute proportions fade as the amblypygid grows older.

I find it amusing that despite my obsession with Amblypygi, I have not yet written anything about them. This website had a gallery of whip spider photos since day one, but I guess I have been waiting for a good opportunity to mention them on the blog, and there is no better time than right now. A recent publication by my colleagues, describing eight new species of whip spiders found in Brazil, has given this group the much-deserved public attention.

Charinus is a genus of relatively small-sized whip spiders with a worldwide distribution. New species are discovered almost annually (the species described in the above mentioned paper are all members of this genus). This one is another new species from Belize soon to be formally described.

Charinus is a genus of relatively small-sized whip spiders with a worldwide distribution. New species are discovered almost annually (the species described in the above mentioned paper are all members of this genus). This one is another new species from Belize soon to be formally described.

Despite their common name (see footnote †) and general appearance, whip spiders are very different from spiders. They cannot spin silk and therefore have no webs. Their first pair of legs has evolved into long, antennae-like sensory organs, which are used for navigation, detection and manipulation of prey, and social communication. It is ironic that what makes whip spiders so visually appealing to some people (myself included), is the same thing that makes them terrifying for other people: the raptorial pedipalps. Enlarged and armed with strong spines, the pedipalps are used as a catching basket for grabbing and impaling prey. They are also used in mating and fighting rituals. The long, spiny “grabbers” make many people cringe in fear at the sight of a whip spider. But make no mistake: these animals are completely harmless to us. They do not have venom, they cannot sting and never bite, and they will do whatever they can to avoid confrontation with a human. It is therefore unfortunate that whip spiders are often if not always used to provoke feelings of fear and disgust, as seen in TV programs such as “Fear Factor” and movies like “Harry Potter” (see footnote ‡).

Adult male Heterophrynus batesii with impressive pedipalp armature. This is the same species shown in the first photo above.

Adult male Heterophrynus batesii with impressive pedipalp armature. This is the same species shown in the first photo above.

Paraphrynus raptator feeding on an assassin bug. The spiny pedipalps are used to impale the prey and bring it closer to the mouth.

Paraphrynus raptator feeding on an assassin bug. The spiny pedipalps are used to impale the prey and bring it closer to the mouth.

For a shy animal, whip spiders sure pack a lot of character. This is something I will address in several future posts. But newly discovered species of whip spiders are always a cause for a celebration. The new paper puts Brazil in competition with Mexico for the title ‘Country with the highest diversity of Amblypygi’ (Brazil wins. For now). One of the possible explanations for the high diversity is the large continental area within the borders of each country, following a classic principle in Ecology that says species richness increases with area. Under the same principle, the smaller neighboring countries are expected to have less species, and this is indeed what we are seeing. Or is it? There might be another reason involved. Because the small order Amblypygi is of no economical and medical importance it is often understudied, so it is very possible that the low amblypygid diversity seen in other countries reflects a lack of research or difficulties in sampling. A similar trend can be found for other groups of organisms sharing the same attributes. It all points to a problem: basic natural history and taxonomic research is becoming less common and receives fewer support, while our conservation efforts aim higher every year. This creates a conflict – how can you protect something if you do not know about its existence? And indeed, the authors of the paper discuss the issue of conservation. The newly discovered whip spiders may already be endangered due to habitat destruction by humans. Nevertheless, their formal description gives them a valid status, and together with other native plants and animals in need of protection, this serves as an incentive for conservation of their natural habitat.

Juvenile Phrynus parvulus found on a moss-covered tree trunk in southern Belize

Juvenile Phrynus parvulus found on a moss-covered tree trunk in southern Belize


† There is a bit of a confusion around the common name for Amblypygi, as several different names exist. I prefer to call them amblypygids, referring to the scientific name of the group, but if I am forced to use a common name I go with whip spiders. One other frequently used common name is tailless-whip scorpions, which refers to their tailed relatives, the whip scorpions or vinegaroons, members of order Thelyphonida (formerly Uropygi). I completely disagree with the use of tailless whip scorpions as a name for Amblypygi. A large taxonomic group cannot be defined by something it does not have, unless this character is found by default in all other related groups. If you disagree, please consider why humans are not called “tailless monkeys”.

‡ One example in particular that I find infuriating is a series of videos recently turned viral, showing a person literally abusing whip spiders to the point that the animal has no choice but to attack using its pedipalps. Because of my deep interest in amblypygids these sickening videos have been forwarded to me multiple times by friends who thought I might like them. Interestingly, the person who made these videos actually loves arthropods, yet he seems to be unaware that his videos are spreading hate and misinformation towards these remarkable arachnids, not to mention the pointless abuse and stress of wild-caught animals (I have never gone after someone with the goal of publicly shaming them and will not mention any names; those who have seen the videos know the guy and what I am talking about).

Epomis beetles – insect response to amphibian tyranny

You can say that I am a little obsessed with Epomis beetles. Can you blame me? They are fascinating creatures. It suddenly dawned on me that since the launch of this blog I have not written a single word about the beetles. Unfortunately, there is a lot of misinformation and inaccuracies on the internet, and even in reputable magazines and books featuring Epomis.

It is one of the weirdest animal stories, one in which a small and seemingly harmless animal prevails against a much bigger animal. A unique case of predator-prey role reversal, where the would-be predator becomes the prey. Amphibians, such as frogs, typically prey on insects including ground beetles and their larvae. Among these beetles, one genus managed to stand out and deliver a proper counterattack to its predators. The Epomis larva has impressive double-hooked mandibles that look like they came right out of a horror movie. It waves them around along with its antennae until the movement attracts a hungry amphibian, which approaches quickly and tries to eat the larva. In a surprising turn of events, the larva is able to dodge the predator’s attack only to leap on the unsuspecting amphibian and sink its jaws into its flesh. It then continues to feed on the amphibian, sucking its body fluids like a leech at the initial stage, and eventually consuming it completely. Sounds like science fiction, I know. But it is real. Furthermore, these larvae feed exclusively on amphibians, and refuse to eat anything else. They are dependent on amphibian prey for completion of their development. This makes the predator-prey role reversal an obligatory one, which is very rare in the natural world.

First instar larva of Epomis circumscriptus showing its double-hooked mandibles.

First instar larva of Epomis circumscriptus showing its double-hooked mandibles.

I first learned about Epomis beetles in 2005, when I was working in the Natural History Collections at Tel Aviv University in Israel. They ended up being a great topic for my M.Sc thesis research, and I continue to study them to this day. The genus contains about 30 species distributed in the old world, with the African continent as the center of diversity. They inhabit the banks of rain-pools and temporary ponds, and synchronize their breeding season with amphibians’ metamorphosis into the terrestrial stage. Most of what we know about Epomis comes from studying three species only (in other words, there is more unknown than known). When the main paper from my thesis was published in late 2011, it became an instant hit in the media (see below). However, one main point of criticism was that the supplementary videos showed the interactions between Epomis and amphibians in a lab setting, which might have triggered an unnatural behavior from both. This is a valid point. We needed a controlled environment to test and prove beyond disbelief several hypotheses regarding the feeding habits of Epomis. Nevertheless, I spent the following years going back and recording the same interactions in the field.

Here is a larva of Epomis circumscriptus displaying luring behavior while waiting for a passing amphibian:

And this is the outcome of the above scenario:

 

To better understand what is happening during this swift encounter, here is a break down of this interaction to several simple steps. As you can tell by the above video, this sequence takes only a split second in real-time:

From enticement to desperation: European green toad (Pseudepidalea viridis) being lured to hunt and getting attacked by a larva of Epomis dejeani. View large!

From enticement to desperation: European green toad (Pseudepidalea viridis) being lured to hunt and getting attacked by a larva of Epomis dejeani. View large!

The larvae are terribly good at this. Even if they are caught by the amphibian’s tongue, they are still able to quickly use their mandibles to grab the amphibian from the inside, whether it is the throat or stomach, and start feeding.

Hard to believe, but this toad is being eaten.

Hard to believe, but this toad is being eaten.

Sometimes the amphibian accidentally steps on the Epomis larva. In this case, the larva will attach to the leg. First instar larva of Epomis dejeani feeding on a Lemon-yellow tree frog (Hyla savignyi).

Sometimes the amphibian accidentally steps on the Epomis larva. In this case, the larva will attach to the leg. First instar larva of Epomis dejeani feeding on a Lemon-yellow tree frog (Hyla savignyi).

While the larvae are specialized amphibian ambushers, the adult Epomis beetles are somewhat more generalist predators. They prey on other arthropods and will sometimes go for the occasional earthworm. But these feeding habits only last until they stumble upon an amphibian again. Then, a hidden memory back from the days they spent as larvae kicks in, and they set out to relive their glory days as amphibian slashers.

Epomis dejeani attacking a European green toad (Pseudepidalea viridis) while holding firmly to avoid falling off. Compare to the photo of the larva attached to the leg above.

Epomis dejeani attacking a European green toad (Pseudepidalea viridis) while holding firmly to avoid falling off. Compare to the photo of the larva attached to the leg above.

In a blink of an eye, the beetle sneaks up on the amphibian and pounces on it, holding firmly to avoid falling off. It then moves to the back, and like scissors uses its mandibles to make a horizontal incision, which disables the hind legs and ultimately prevents the amphibian from escaping. As if this was not gory enough, both adult beetles and larvae are particularly fond of eating the amphibian’s eyes. It is like a sick twist of revenge for the insects: after millions of years of suffering under the constant threat of predation by amphibians, they are able to fight back. Not only they hunt their potential predators and slowly eat them alive, but they also cripple them and peck their eyes out right from the start.

Remains of a partially eaten amphibian in the vicinity of temporary ponds are usually a good sign for adult Epomis activity in the area. Central Coastal Plain, Israel

Remains of a partially eaten amphibian in the vicinity of temporary ponds are usually a good sign for adult Epomis activity in the area. Central Coastal Plain, Israel

Epomis dejeani guarding a recently captured European green toad (Pseudepidalea viridis). The beetles can get very territorial over prey items.

Epomis dejeani guarding a recently captured European green toad (Pseudepidalea viridis). The beetles can get very territorial over prey items.

How did this phenomenon evolve? To be honest, we do not know exactly. But it is possible that somewhere in the evolutionary past, Epomis beetles used counterattack behavior, instead of escaping, as a defense against amphibians. Such behavior could have later evolved into exploiting amphibians as a source of food. The amphibians probably could have not evolved to recognize and avoid this behavior because the majority of insect prey they encounter poses no threat to them, as opposed to the relatively uncommon Epomis beetles. Another interesting point, is that both adults and larvae of Epomis lack any venom, yet the amphibian is quickly subdued and stops resisting after being caught, even while it is slowly being devoured alive.

One common reaction that I get in response to this study is that it was “cruel”, involving poor helpless amphibians that were sacrificed in the name of science. Some people even go further to suggest that I am a sadistic scientist somehow enjoying this. It could not be farther from the truth: This is a natural phenomenon and Epomis beetles must kill and consume amphibians in order to exist. Nature is cruel. We tend to think of amphibians as cute and helpless animals, but from the insects’ perspective they are actually cold-blooded killers (pun intended), gulping every small creature in their path. Moreover, the reality of this study is even harsher: the amphibians would have still died even without me using them as food for Epomis, because the puddles they were found in as tadpoles were quickly drying out. As for myself, I cannot begin to describe the emotional stress I suffered during this research, just so I could bring Epomis’ fascinating biology to the spotlight. I love amphibians, and it was disheartening for me to watch them die so many times. Throughout the study I kept telling myself: “I am going to hell for this, no doubt about it”.

In the past few years I have been following the response to the story of Epomis beetles. More sightings of the beetles are being reported from around the world. There are some excellent blog posts (1,2,3,4, and do not miss Bogleech!), news reports (1,2,3,4,5), videos and TV segments, radio interviews and podcasts, and even Wikipedia pages. Epomis has found its way into artwork. There is a metal band named after the beetles. It is very possible that this is the discovery I will go down in history for, and that is fine by me. Hollywood, I am waiting by the phone for your call. To end this post on a positive note, here is a fitting limerick that I love, written by the talented Celia Warren:

Of the genus Epomis, folk say,
Their larvae at first seem like prey,
But they’ll bite a frog’s throat,
Leave it paralyzed, note!
Then they’ll eat it without more delay.

Giving birth to a botfly

Sitting at my dentist chair for 40 minutes and suffering through the shrill sound of the ultrasonic cleaner, I suddenly started to feel contractions from my chest. Oh, no. Not now. Is it really happening? If it happens now this will be a visit I will never forget. Am I getting into labor?

2014 hit me hard in the face with all its goodies, that it was difficult for me to pinpoint the best moments. I still have one more story to share before I bid farewell and move on. For me, 2014 ended with a blast.

The story actually begins in fall 2013. Shortly after returning from BugShot Belize, I noticed that three mosquito bites on my chest were not going away. They became red, started to feel even itchier, and occasionally there was a slight pinprick sensation. I immediately suspected they harbored botfly larvae, and indeed confirmed this after a couple of days when the sensation became more intense.

Hypoderma bovis is a species of botfly that attacks cattle. The resemblance to a bumblebee is not incidental. Upper Galilee, Israel.

 

Botflies belong to the family Oestridae, whose larvae develop in the body of mammals as endoparasites. They are mostly known as pests of cattle, but also of rodents and other small mammals. At least one species, Dermatobia hominis, attacks primates and, as I learned the hard way, humans. And it does this in the most incredible way: the female botfly waits in ambush for a female mosquito to pass by, and when the blood-sucking insect shows up, a chase ensues between the two. The botfly grabs the mosquito in mid-air and takes her captive to the ground level, where she proceeds to do something unique to Dermatobia botflies – she starts to lay eggs under the abdomen of the now-immobilized mosquito. When she is done, she releases the mosquito from her grasp. Now the botfly has a carrier, a vessel to transport the eggs to a suitable host, preferably a mammal. Once the female mosquito locates a bloodmeal and lands in order to bite, the mammal’s body heat triggers the botfly eggs to hatch, and tiny larvae drop to the mammal’s skin. They quickly start to burrow into the skin, head in first. Some take advantage of existing pores, such as hair folicules or even the mosquito bite itself. The small larvae have several rings of curved hooks pointing backwards; these hooks assist in anchoring the larva inside the host’s tissue and prevent removal. After fully embedded into the mammal’s flesh, the larva (which is a foreign object) excites the body’s immune system, and feeds on the inflammation response and white blood cells that arrive to the area. Its only connection to the outer world is through the entrance hole, now called punctum, from which it extends its spiracles for breathing air.

This beautiful mosquito (Psorophora sp.) is known to be one of the vectors for D. hominis eggs. Photographed in Belize, in the same location where I got my botfly larvae.

 

When I first learned about Dermatobia hominis in Intro to Entomology course back in 2004, I could not help but wonder how it feels to have an insect living inside one’s body; whether it is painful; and does it show on the outside? Little did I know that I would become a host for the same species 10 years after. Well, it was painful indeed. Sharp, ticking pains that came and went in cycles. I immediately sought medical advice and came across a medical paper describing a method for removing botfly larvae using a suction pump. Fortunately for me, the leading author of the paper was a bus drive away. There was much excitement at the Tropical Diseases Clinic, when several doctors and medical students gathered to see my botflies. We removed three tiny larvae, and I was released home. Then, in the evening of the same day, I felt that sharp pain again from all three locations. Over the next days, the pain became worse, think of chest-stabbing, or corkscrewing in pulses with heated iron and you get the idea. There were larvae still in there. And it seemed they were growing faster because there was no competitor in there with them (the larvae we already removed). To make a long story short, I managed to remove one of these larvae (on Halloween Eve nonetheless!), accidentally killed another at the clinic (only to be removed later by me), and failed to remove the third one. It continued to remind me of its existence with pseudo heart attacks several times every night until it finally died and the punctum sealed over it.

This was quite the experience, and we even published a report of the case in a medical paper. Originally, I wanted to keep one of these larvae until completion of its development. As an Entomologist, I was eager to see the adult fly, let alone this might be the only chance I could give something in return after collecting and killing many insects for my scientific work. However, I was not lucky, and I started to accept the possibility that I will not get another botfly larva, surely not in such a convenient location again. And so, a year later I returned to Belize, not even considering the option that it might happen again. Remembering the lancinating pain that I experienced, I tried to be careful and well-protected from mosquitoes this time. So you can imagine my surprise after I returned home, when I found a new botfly larva in my chest, almost in the same location as last year!

At first I repeated the “routine” of visiting the Tropical Diseases Clinic, but the larva was still too small to be removed. Then I decided to leave the area as is and give the larva the space it needs. I was amazed to find out this larva was not even slightly painful. The feeling was completely different, I could easily feel it moving, but there was no discomfort about it. This is it. I am keeping it.
Maybe I should pause here and say that a botfly is probably the “friendliest” parasite one can wish for. It does not transmit any diseases, does not cause any significant damage to the body, does not leave any scars, keeps its area clean from infections by antibiotic secretions and most importantly – unlike other parasites, once it finishes doing its thing, it leaves on its own!

Portrait of human botfly (<em>Dermatobia hominis</em>) larva. The resemblance to a walrus is incidental.

Portrait of human botfly (Dermatobia hominis) larva. The resemblance to a walrus is incidental.

 

For more than two months I nurtured the larva, patiently observing while it was growing inside me. Photographing it was not easy, and essentially could only be done facing a mirror, but I learned the trick and eventually got used to operating the gear backwards. It allowed me to take this photo of the larva’s spiracles as it is breathing from the punctum (this might be graphic to some people, so you can view it here). But like I said my real goal was to see the adult fly, and I was restless in the final two weeks of the larval development in fear that I will miss the event. The botfly larva does not pupate inside the host. It first has to leave its host’s body, drops off to the ground and then quickly looks for a suitable place for pupation. In the end, the contractions I felt at the dentist were a false alarm, and I could not feel anything when the larva emerged eventually.

Human botfly (Dermatobia hominis) larva after emergence from its host, searching for a place to pupate.

Human botfly (Dermatobia hominis) larva after emergence from its host, searching for a place to pupate.

 

Incubating the puparium has to be the hardest part in keeping a human botfly. In a fascinating paper from 1930, Lawrence H. Dunn describes how he deliberately allowed two botfly larvae enter his arm to document their development. Only later he found out that prior to his actions he was already infected with four additional larvae (on his other arm and leg). The paper is not an easy read, as it spans through the various sensations and types of pain the author experienced during this period. Eventually he had all his six larvae emerging as late third-instars, pupating and turning into adult flies. Unfortunately, this last part of the paper is poorly written and lack details. How moist was the pupation substrate and what was its composition? Did the larvae burrow or stayed on its surface? How long after emergence the adult flies started activity? And were there any losses during the pupation period? That last question is extremely important because I have heard of many failures in keeping Dermatobia hominis for the purpose of getting adults, and they mainly happened during the pupal stage. This is why I was so thrilled to find the adult fly one afternoon waiting in the container. What a great ending to 2014. And what a magnificent fly it is! Glowing red eyes, a pointy head with a bright silvery “face”, and the most dazzling blue abdomen, striking with metallic gloss. For me, this was literally the miracle of birth. No matter how I look at it, this fly is my own flesh and blood.

Human botfly (Dermatobia hominis) adult, fresh after emergence from its puparium (left)

Human botfly (Dermatobia hominis) adult, fresh after emergence from its puparium (left)

 

Larva and adult of the human botfly (Dermatobia hominis). Hard to believe this is the same animal.

Larva and adult of the human botfly (Dermatobia hominis). Hard to believe this is the same animal.

 

Totally worth it.

 

In this day and age, even a fly can take a selfie.

 

Was it worth it? Absolutely.

Piotr Naskrecki had his own personal experience bringing (two!) botflies to adulthood. You can read his blog post here. And do not miss the postscript!

UPDATE (12 Jan, 2015): Piotr has just posted a video about his botfly. Please go to his blog and watch it. I cannot recommend it enough; this is most likely the only filmed documentation that follows the botfly throughout its development to adulthood in a human host:
http://thesmallermajority.com/2015/01/12/dermatobia-redux/
Thank you everyone for the positive response to this story!