A Pit Bull Among Insects (and related spearbearers)

追加: 2026-05-12

[00:00:00]Tonight, we are in the mountains of central  Costa Rica and we are looking for something called the Pit Bull Katydid, which is  certainly quite an odd looking bug, and we will also be looking for a couple of  its close relatives known as spearbearers.

[00:00:14]We have our first target back there. You can see  a Rhinoceros Katydid resting on that leaf there.

[00:00:21]Here it is up close. You can see why it gets its  name. Oh. Okay, I was successful in retrieving our Rhinoceros Katydid. These are known scientifically  as Copiphora rhinoceros. Other species in the genus Copiphora also have horns which is why  they're collectively known as spearbearers, but this species possesses one of the most  prominent horns of all of them. And there are a good number of species in that genus.  Most spearbearers just have a little point but some species even have a curved or rounded horn.  This horn is thought to protect these katydids from bats that pick insects off of leaves. This  is in contrast to some other insects that use their horns for intraspecific combat, often  in pursuit of a female mate. This is perhaps the most well-known species of spearbearer,  not only because of the prominent horn, but also because they are so common throughout Costa  Rica. And of course, the tourism industry in this country is largely based on viewing wildlife, so  many people from outside of Costa Rica encounter them as well. Because these are so common, the  chirp they produce is one of the more commonly heard sounds in the rainforest. It doesn't sound  particularly special, but I did get a recording anyway. Outside of Costa Rica, these can be found  in Honduras, Nicaragua, and Panama, where they are found in rainforests at sea level all the way  up to cloud forests at 1,600 meters in elevation.

[00:01:46]Over here on this plant, we have a frog. And  even from a short distance, it's not too easy to see. This is a Hyalinobatrachium fleischmanni, or  Fleischmann's Glass Frog. And I'm really glad that we found this particular individual because the  last two that I encountered were far out of reach.

[00:02:09]One was way up in a tree and the other one down in  a ravine. But regardless, this is still one of the most common species of glass frog of the several  that can be found in this area. Also, among the local species of glass frogs, or Centrolenidae,  this one can be distinguished by the small faded dots that pepper its dorsum. This isn't unique  per se, but if you were wondering what these and potentially other glass frogs sound like, I  heard them vocalizing just a moment ago, and the sound is nearly identical to the chirp of a smoke  detector. This frog has a wide distribution. It is found from the southern tip of Mexico through much  of Central America as well as far northwestern South America. And as you might expect, they are  found in pretty much any rainforest setting. Among the many glass frog species, these are average in  size. Most are around 2.5 cm, but can exceed 3 cm, particularly with females. As opposed to  other glass frogs whose organs are visible through their underside, which is why they are  called glass frogs, Fleischmann's Glass Frog possesses a sheet of guanine that covers half  of its heart, its liver, and digestive system.

[00:03:18]You can't see it right now, but beneath this leaf,  there's a Phoneutria depilata. This is a species of wandering spider, or banana spider. If I put  my hand behind it, you can see that this is quite a large species of spider. You'll notice some  orangish color on the chelicerae. The undersides of its front legs are lightly banded and also have  a little bit of yellow coloration. And all of this culminates in an aposematic warning when they feel  threatened. I'm not going to provoke this one, but if we were to see its startle display, its  four front legs would point forward and up, therefore exposing its brighter colors in our  direction. This is behavior that is seen in other Phoneutria, or wandering spiders, as  well. In fact, there are a couple of species whose display is far more brilliant than that of  this species here. Being as large as they are, these spiders have been documented eating  vertebrates such as anoles. But of course, they more frequently feed on bugs, some of which  may be nearly their own size. While we found our spider on the ground, these are semiarboreal and  they often take refuge in foliage during the day when they are inactive. And lastly, this is the  only Phoneutria that can be found outside of South America and possibly the most commonly encountered  by people of all of the members of its genus.

[00:04:41]We have a Pit Bull Katydid back here on this  plant and this is our main target for tonight.

[00:04:49]These are known scientifically as Lirometopum  coronatum. While this katydid is not a spearbearer like the last species that we looked at and  the next one that we're going to look for, it is very closely related. In fact, within  Costa Rica, this should be the most closely related katydid to the spearbearers, or  Copiphora. And this is backed by molecular evidence that suggests that they are sister  genera. These carry the common name ‘Pit Bull Katydid’ because they are carnivorous  like the last species that we looked at, the Rhinoceros Katydid. Say what you will about  pit bulls named Daisy or Cupcake or whatever, but I did not come up with this common name, so  please do not come after me in the comments. They eat mostly things like bugs, but I'm sure they're  capable of eating small vertebrates as well, such as little frogs or lizards. I was able to  observe one of these the other night feeding on a katydid that it had presumably killed that  was almost the same size. And I also recently saw a small juvenile that was feeding on something  that I couldn't really identify. The scientific name of this insect refers to its unique face.  ‘coronatum’ means ‘crowned’ or ‘wreathed’ and, of course, it's in reference to the yellow  bumps that you see on its face, especially the ones off to the sides. In some individuals of this  species, those bumps are orange instead of yellow.

[00:06:13]We are currently in a drainage ditch and down here  is a turtle. This one is Kinosternon leucostomum.

[00:06:23]This is the White-Lipped Mud Turtle. Not a very  large species. And that name checks out because they do indeed have a pale beak. And this is  what the scientific name is referring to as well. ‘leucostomum’ basically means ‘white  mouth’. And on the topic of coloration, not all of them have the orangish crown that  we see on this one. Others have speckling on their head instead or nothing at all, so this is  an especially good find. I can't say that I've handled all that many turtles, but this one is  especially odorous. It smells quite similar to a dead fish, actually. And this is not a surprise.  Mud turtles are also called musk turtles because they produce this smell on purpose as opposed to  being stinky from their lifestyle alone. And this stinkiness is supposed to deter predators. And  unfortunately, the white-lipped mud turtle is a very notable victim of poaching. Between 2019 and  2023, over 10,000 of them were seized in Mexico, which is a country that they are native to. And  as I said, this is quite a small turtle. In fact, in the region that we are in along with other  Kinosternon species, this is the smallest turtle.

[00:07:37]Time for an intermission to look at moth species.  The larger one that we have here is Copaxa curvilinea and the smaller one is Adeloneivaia  jason. Neither of these have a common name and I found them both by attracting them to a  sheet with a light. This larger moth that we're looking at is a rare species of saturniid,  or silk moth, found in lower Central America, specifically southern Nicaragua, Costa Rica, and  western Panama. Despite being as rare as it is, the caterpillar of this species is known. And  in fact, even the host plant of the caterpillar is known as well. The larvae are green, orange,  yellow, and blue. Female moths of this species lay their eggs in groups. The early instar  caterpillars feed together and disperse as they grow larger. And this smaller moth that  we have here, the Adeloneivaia, by contrast, is one of the more common members of its genus,  being found across much of the neotropics. And the adults of this species typically live  less than 10 days. The larvae feed on the leaves of inga trees, which are really  common around here. And as you can see, this moth is a dead leaf mimic, which is  really common for a lot of silk moth species.

[00:08:44]I've spotted a well-camouflaged  snake down here in the leaves.

[00:08:50]This is a Porthidium nasutum, otherwise known as  the Rainforest Hognosed Viper. This is a species that we have seen on the channel before, but  I figured I'd stop to take a look at this one because it's quite dark in comparison to the last  one that we saw. Speaking of appearance, as you've probably guessed, this species is a sort of leaf  litter mimic. This is because these snakes are fully terrestrial, so having this dorsal pattern  helps to camouflage in most areas of the forest floor. And of the nine hognosed viper species,  pretty much all of them exhibit crypsis to some extent. Also, regarding this snake's appearance,  they are quite variable both in coloration and patterning. And one thing that you will see in  other individuals but isn't present on this snake is the dorsal stripe. Usually this dorsal stripe  is copper or beige in color. These are distributed from southern Mexico to western Ecuador and this  range is fairly discontiguous. As far as we know, there are between roughly 5 and 10 isolated  populations, though some gaps have filled in a bit over time with increased sampling, much  of which has been incidental for this species.

[00:09:57]Over here on this leaf, we have our third  target species for tonight. This is Copiphora hastata. Let’s see if I can get it to crawl  on to my hand. These are commonly known as Brown-Faced Spearbearers. And indeed, this  species does have a mostly brown face. Many of the spearbearers have a scientific  name that makes reference to their horn, as is the case with the last species that we  were looking at, Copiphora rhinoceros. This one has an extremely straightforward name in that  regard. The specific epithet ‘hastata’ is Latin and contains two parts: ‘hasta’ means spear and  the ‘-ata’ suffix means possessing. So together that is ‘possessing a spear’. And so you'll  notice that the epithet basically means the same thing as the common name for this genus,  the spearbearers. Still focusing on the horn, you can see that this one is rounded as opposed to  what we observed on the Rhinoceros Katydid. This makes it quite special in that there are only  a few species of spearbearers with that trait.

[00:10:55]Another difference is its coloration. Aside from  its face, of course, the ventrum is spotted and blue and the bottom of its feet are also blue.  Though I must say that the blue on the feet is not very noticeable in our individual.  This is a bit random, but this species, the Brown-Faced Spearbearer, is the only species  of Copiphora that I've ever seen at a light trap.

[00:11:24]Down here in the leaf litter, we have a Glysterus  metatarsalis. This is a species of harvestmen, or Opiliones. There are six species  of Glysterus, four of which have an apophysis. That is the protrusion that you  see on its butt. And of those four species, only one of them has an apophysis that comes  to a single point, that being the species that we have here. And on the other three  species, it's shaped more like a trident.

[00:11:52]Speaking of morphology, the name metatarsalis  means pertaining to the metatarsus, which is a segment on the leg. So in all likelihood, that  particular segment on one of its pairs of legs is a defining characteristic for this species. This  is a highly terrestrial harvestman that mostly hides within the leaf litter, and it appears  to have a preference for drier nights based on the handful that I've seen. The worst case of  parasitism that I have ever seen on a harvestman was on a Glysterus. Harvestmen are a fairly  common host for larvae in the Trombidiidae family, which are the little red dots that you see on  a lot of bugs, but I believe the ectoparasites that I saw on the Glysterus were the pupae of  some kind of fly. It would be interesting to know whether that fly kills its host or not  in its development. I put another species of Glysterus next to it so you can see the  difference in having an apophysis versus not.

[00:12:47]Down here is another katydid. This one is  Neoconocephalus [triops]. The spearbearers that we're looking for belong to a group  called Copiphorini. I wanted to show you a more average looking member of that group  and that's this katydid right here. These are not so much carnivorous but more so granivorous  and they live mostly in open areas like fields instead of inside the rainforest. So yeah,  most Copiphorini species look like this one here. Or another good representative  would be something like Erioloides.

[00:13:21]You can see an anole there on that plant that  I just woke up. This is an Anolis biporcatus.

[00:13:33]These are commonly known as the Neotropical  Green Anole. This is one of the larger anole species found around here along with species like  the Pug-Nosed Anole and it's also one of the most vibrant green. Their large size allows them to  prey on animals that most other anoles would not, such as snakes. Predation of snakes by anoles  has only ever been recorded in a few species and, of course, in the overwhelming majority of cases,  it's the other way around: anoles are a very common source of food for snakes. And in addition  to snakes, the Neotropical Green Anole has also been documented eating tarantulas, large silk  moths, owl butterflies, and cicadas. Obviously, these are just the notable prey items and  this species feeds on all kinds of other bugs, usually smaller in size. The name ‘biporcatus’ is  Latin and it means having two ridges. According to the original description of the species, this name  refers to the rostrum, or snout, of this lizard.

[00:14:32]Perhaps more specifically to the subtle  ridges that extend from the eyes to the nose.

[00:14:45]Here in this bush, you can see we have another  Rhinoceros katydid, but that's not all. Right up here, we have yet another Rhinoceros katydid.  And let's see, we should be able to see the female from down here as well. Yeah, there she is. It's  not a coincidence that these two are next to each other and I am going to carefully extract  the female off camera. As you can see here, I broke the leaf off of the plant that the  Copiphora was sitting on. I'm being extra careful here for the same reason that I pointed out the  male katydid that was sitting nearby, which is that this female is carrying a spermatophore. This  is a structure that is made up of two main parts, each with a different purpose. The inner ampulla  carries the sperm and the spermatophylax, which is the outer casing, is the edible part. In  fact, it's possible that we are seeing this female feed on the spermatophylax right now. It's chewing  on something at least. That spermatophylax is rich in proteins and its job is to distract the female  during the overall process. This is because she might otherwise eat the entire spermatophore. As  you might have already inferred, the part of the mating process that requires contact is quite  brief since the female effectively continues the mating process after the spermatophore  has already been transferred from the male.

[00:16:06]Down here on this leaf is a caterpillar I really  need to show you. This is Hypna clytemnestra, or commonly known as the Silver-Studded  Leafwing Butterfly. The adult butterfly looks pretty average, especially for the  tropics, but this caterpillar is one of a kind. The crown that you see on its  head is somewhat rare in caterpillars, but can be seen in other leafwing species, as well  as unrelated species such as owl butterflies and their allies. But I can't think of another  caterpillar with the same spine structure as this one. Across the order Lepidoptera, there  are many different forms of bristles, setae, scoli, spines, and other defensive structures, but  these certainly stand out. And if you're curious, they are not capable of stinging, but  those spines are fairly sharp. Also, the butterflies are fairly common, but larvae  like this one are not too easy to find. The adult butterflies do not go for flowers, but  instead prefer to feed on rotting fruit. They're called leafwings because they mimic dead leaves,  but the adults are not entirely brown; they have whitish streaks on their forewings, which is  why ‘silver-studded’ is in their common name.

[00:17:14]Up there on that plant was our Silver-Studded  Leafwing caterpillar. And down here, there's a pretty interesting looking caterpillar. And I  will admit I have no idea which species this is, but I absolutely had to show you due to the  black and orange color combination as well as that ridiculously fuzzy head that it has.  It's also moving a bit strangely. Usually caterpillars move their heads like  that when they're building a cocoon.

[00:17:45]Over here on this leaf, we have a frog. This is  Smilisca phaeota, otherwise known as the Masked Tree Frog; one of the larger species of tree frog  that is out here. And the name ‘Masked Tree Frog’ refers to the dark bands that they have near their  eyes. These dark bands are thought to obscure their eyes, which makes it more difficult for some  predators to spot them. These are also called the New Granada Cross-Banded Tree Frog, New Granada  being an 1800s Republic that existed in what is now part of Costa Rica, Panama, and Colombia. And  indeed, this frog can be found in all of those countries. As you may know, many amphibian species  in the neotropics are experiencing population declines, many quite severe. This is one of the  few species which appears to be more resistant to the effects of the Anthropocene. They're  able to persist on grazing land, plantations, and other similarly disturbed environments. Along  with the famous Red-Eyed Tree Frog, these are among the most commonly encountered hylids, or  tree frogs, in Costa Rica. The specific epithet ‘phaeota’ is derived from the Greek ‘phaeos’ which  means dusky, dark, or brown. This is the same root that's used to construct Phaeophyceae, otherwise  known as the brown algae. And speaking of color, while nearly all of these frogs are green,  brown, or yellowish across their distribution, some vibrant blue individuals can be seen  in Costa Rica in at least two locations.

[00:19:15]We have another Pit Bull Katydid right down here.  You can see this one is a juvenile unlike the last one. It looks like it only has one more molt left  before it becomes an adult. This has to be one of the goofiest looking insects that I have ever  witnessed. The size of its head relative to the rest of its body is truly a sight to behold.  This guy has the build of an ice cream cone.

[00:19:38]Since we've been discussing etymology a fair  amount in this video, I might as well explain the name ‘Lirometopum’ as well. It's a Greek  name that contains two parts. ‘Liro’ usually refers to a smooth structure and ‘metopum’  means ‘face’ or ‘forehead’ so, together, this name could mean ‘smooth face’, though  I'm not entirely convinced. Its completely flat and circular shape is one that is quite  rare in Orthoptera and insects in general.

[00:20:03]In fact, this peculiar face makes this  species incredibly easy to identify.

[00:20:11]Two more species of silk moths to end the night  here. The drably colored one that we have here is Periphoba arcaei and the other one is Citheronia  bellavista. And once again, neither of these species have a common name. Citheronia bellavista  is one of the more common species of regal moths, which is a common name that's given to the  entire genus, and it has a couple of subspecies to its name. Ours is C. bellavista bellavista  and the other one is C. bellavista cinerea, cinerea meaning ashy, and indeed that other one  is quite gray. In this region, the larvae feed on plants known as leafy mistletoes. And these larvae  are almost uniformly gray with two lateral white stripes. You can see it’s feigning death here.  This behavior is not reliably observed in regal moths or Citheronia, especially in comparison  to other silk moths, or saturniids. And now, regarding this Periphoba, it's not the most  striking silk moth, but I thought I would show a species similar in size to the regal  moth that also feigns death. Death displays can be found in a number of saturniids.  Out here, this behavior can most reliably be seen in Hylesia species, which are quite  a bit smaller by comparison. These Periphoba, though they don't have false eyes on their hind  wings, are very closely related to Automeris species. They're also much less common, not  nearly as diverse, and not as widespread either.

[00:21:33]Well, that will be all for this video of looking  for Pit Bull Katydids and spearbearers. As always, I hope you enjoyed and thank you for watching. :D