Tag Archives: taxonomy

The Scaly Crickets

by Joseph DeSisto

Among many new species named today, some of the most unusual were three new crickets from Southeast Asia (Tan et al. 2015). These crickets belong to the obscure and poorly-known family Mogoplistidae, cousins to the more recognizable (and audible) field crickets (Gryllidae). They look like field crickets too, except that their bodies are covered in scales.

A scaly cricket (Arachnocephalus vestitus). © Entomart.

A scaly cricket (Arachnocephalus vestitus). © Entomart.

When you touch a butterfly’s wings, you might notice a fine, powdery substance rubbing off on your fingers. The powder is made up of microscopic scales, which cover the wings of butterflies and moths. Scales give the wings their color, but they also provide insulation and protect the wings during flight. Perhaps most importantly, scales can fall off and make the wings slippery. This allows butterflies and moths to evade a careless hand as easily as a wet bar of soap.

The scientific name for butterflies and moths is Lepidoptera, which translates to “scaly wing” — scales are one of the most important features defining the group. However, many other groups of insects also have scales. Mosquitoes and silverfish have them, and so do scaly crickets.

The scales of a scaly cricket (Ornebius formosanus). Figure from Yang and Yen (2001), licensed under CC BY 2.0.

The scales of a scaly cricket (Ornebius formosanus). Figure from Yang and Yen (2001), licensed under CC BY 2.0.

Cricket scales, like those of butterflies and mosquitoes, are microscopic, powder-like, and easily shed. To really appreciate their beauty, a scanning electron microscope is needed. The first look came in 2001, when Yang and Yen published the first high-resolution images of cricket scales.

Aside from being scaly, scaly crickets aren’t all that unusual. They are adaptable, able to eat decaying plants as well as other insects, and they tend to live in moist sandy habitats. No scaly crickets are capable of flight, and females lack wings entirely, but the males do have small wings which they rub together to make chirping sounds (Love and Walker 1979). Click on the audio file below to listen to an amorous male scaly cricket (recorded by Thomas J. Walker).

Of the three new species, two were found in the Sakaerat Biosphere Reserve, in Thailand. This reserve consists mainly of high-altitude dry forest, with a few grasslands, and is home to many endangered species including tigers and giant black squirrels.

The third cricket is native to Pulau Ubin, an island off the coast of Singapore. Pulau Ubin is one of the last remaining wild areas in the already tiny country. Singapore’s government has been eager to develop portions of the island, but in recent years tourism has become more profitable. Fear of losing foreign visitors has encouraged officials to protect, rather than level, valuable habitat. For now, the status of the new scaly crickets appears secure, but in rapidly urbanizing Southeast Asia, nothing is certain.

A scaly cricket (Mogoplistes brunneus). © Entomart.

A scaly cricket (Mogoplistes brunneus). © Entomart.

Cited:

Love R.E. and T.J. Walker. 1979. Systematics and acoustic behavior of scaly crickets (Orthoptera: Gryllidae: Mogoplistinae) of eastern United States. Transactions of the American Entomological Society 105:

Tan M.K., P. Dawwrueng, and T. Artchawakom. 2015. Contribution to the taxonomy of scaly crickets (Orthoptera: Mogoplistidae: Mogoplistinae). Zootaxa 4032(4): 381-394.

Yang J. and F. Yen. 2001. Morphology and character evaluation of scales in scaly crickets (Orthoptera: Grylloidea: Mogoplistidae). Zoological Studies 40(3): 247-253.

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Basketballs, Shark Teeth, and Millipedes: Meet the Haplodesmids

by Joseph DeSisto

I feel like I’m on a roll with the whole common-name-inventing thing, so I’m going to have a go at another millipede family: the Haplodesmidae. These millipedes are poorly known, largely because they are often tiny and cave-dwelling. Beneath the microscope, however, they become utterly captivating. The haplodesmids have intricately shaped and textured exoskeletons, appearing almost as if they were crafted by an artist with very tiny instruments. For the purposes of this blog they will be called the “sculptured millipedes.”

For example:

The star-shaped haplodesmid Eutrichodesmus asteroides. Photo from Golovatch (2009b), licensed under CC BY 3.0.

The star-shaped haplodesmid Eutrichodesmus asteroides. Photo from Golovatch et al. (2009b), licensed under CC BY 3.0.

The millipede above has curled into a protective spiral, with its head at the center. The species name asteroides means “star-like” and refers to the shape formed when it spirals.

Here’s another, Eutrichodesmus incisus, newly described in Golovatch et al. (2009a) from remote Chinese caverns:

A preserved specimen of Eutrichodesmus incisus, shown under a scanning electron microscope. Photo from Golovatch et al. (2009a), licensed under CC BY 3.0.

A preserved specimen of Eutrichodesmus incisus, shown under a scanning electron microscope. Photo from Golovatch et al. (2009a), licensed under CC BY 3.0.

Notice the way the back plates, or tergites, have bumps and sutures like the surface of a basketball. They even look a little fuzzy, but it isn’t fuzz — each one of those tergites is covered in microscopic spines. Here’s a close look at the junction between a tergite and a prozonite (the part of a segment that goes before/under the tergite).

Tergite and pretergite of E. incisus. Photo from Golovatch et al. (2009a), licensed under CC BY 3.0.

Tergite and prozonite of E. incisus. Photo from Golovatch et al. (2009a), licensed under CC BY 3.0.

The tergite and prozonite have very different textures! Not only is the tergite bumpy, each bump is covered in tiny, finger-like projections or microvilli:

A single bump on a tergite of E. incisus. Photo from Golovatch et al. (2009a), licensed under CC BY 3.0.

A single bump on a tergite of E. incisus. Photo from Golovatch et al. (2009a), licensed under CC BY 3.0.

The prozonite, meanwhile, is covered in tiny spines. If we look even closer we can see that these spines even come in two different shapes, neatly arranged in rows like a shark’s teeth:

The surface of a pretergite of E. incisus. Photo from Golovatch et al. (2009a), licensed under CC BY 3.0.

The surface of a prozonite of E. incisus. Photo from Golovatch et al. (2009a), licensed under CC BY 3.0.

Pretty cool, right? At this point you’re probably wondering why sculptured millipedes look so weird, but I haven’t even shown you the weirdest one. The most bizarre-looking haplodesmid is star-shaped like E. asteroides, but even more so. Also like asteroides, it was only just described in 2009, from a series of Vietnamese caves (Gorovatch et al. 2009b).

The even-more star-shaped Eutrichodesmus aster. Photo from Golovatch et al. (2009b), licensed under CC BY 3.0.

The even-more star-shaped Eutrichodesmus aster. Photo from Golovatch et al. (2009b), licensed under CC BY 3.0.

Back to the obvious question: why are sculptured millipedes so sculptured? It’s an interesting question, but unfortunately not too much attention has been paid to the minute details of these already minute millipedes. In addition to being tiny, sculptured millipedes are also almost always found in caves, which are often remote and difficult to explore.

So, no one really knows why aster is star-shaped, or why incisus has tiny shark-teeth on its body. If I had to guess I would say that aster‘s projections make the millipedes more difficult to swallow, which is one of the reasons millipedes form spirals in the first place.

As for the teeth on the prozonites — I really haven’t got a clue.

The sculptured millipedes, like many invertebrate families, were barely known until a few intrepid taxonomists got to work on documenting the species. Now that this is starting to happen, perhaps we will find out what their strange projections/ridges/teeth/villi are for. I’m betting we will, and I certainly hope so — whatever reason there is, I’m sure it’s amazing.

Cited:

Golovatch S.I., J. Geoffroy, J. Mauries, and D. VandenSpiegel. 2009a. Review of the millipede family Haplodesmidae Cook, 1895, with descriptions of some new or poorly-known species (Diplopoda, Polydesmida). ZooKeys 7: 1-53

Golovatch S.I., J. Geoffroy, J. Mauries, and D. VandenSpiegel. 2009b. Review of the millipede genus Eutrichodesmus Silvestri, 1910 (Diplopoda, Polydesmida, Haplodesmidae) with descriptions of new species. ZooKeys 12: 1-46.

Key-making: Illustrating the Stone Centipedes of New England

by Joseph DeSisto

Have you been waiting on the edge of your seat for an identification key to the New England stone centipedes? Do you often find yourself up late at night, eagerly searching for recent articles in taxonomic journals, only to have your chilopodological hopes dashed?

Well, your wait is (nearly) over! This week I started illustrating a key to the stone centipedes of New England. A total of 18 species are represented, the product of more than a year of relentlessly identifying hundreds upon hundreds of museum specimens, but the key is finally coming! It will be ready to send off to a journal by the end of the semester.

It will be ready. It will be ready. It will be ready.

Fangs! Photo by Joseph DeSisto.

Fangs! Because, fangs! Photo by Joseph DeSisto.

Anyway, I spent today working on line drawings, and I’ve included a few outlines here — note that the images below are not the images that will appear in the key itself. Rather, these are preliminary outlines I have made to provide a template for the final illustrations. They still need a lot of work, including shading.

The outline of the photo from earlier looks like this:

The prosternum (with fangs!) of Bothropolys multidentatus, one of New England's largest and commonest stone centipedes. Illustration by Joseph DeSisto.

The prosternum (with fangs!) of Bothropolys multidentatus, one of New England’s largest and commonest stone centipedes. Illustration by Joseph DeSisto.

Not bad for a first go, huh? Actually it was my fourth or fifth go, but moving on …

How does this work? First, I use a fancy microscope and an extra-fancy image-stacking computer program to make nice clear images of a centipede feature like the one above. Then I print out that photograph, and use a micron pen to outline, directly on the picture, the drawing I want to create. When the photograph is sufficiently defiled by lines, scribbles crossing out lines, and more lines, I put the paper on a light box and copy my outline onto tracing paper.

Then I copy that onto another piece of tracing paper. And another. And another, until finally I have one that’s good enough to look at without cringing.

The centipede from earlier is Bothropolys multidentatus, a common and large centipede in New England. Below I’ve illustrated the pores on the coxae (basal segments) of the 14th pair of legs:

The 14th coxae, viewed from below, of Bothropolys multidentatus. Illustration by Joseph DeSisto.

The 14th coxae, viewed from below, of Bothropolys multidentatus. Illustration by Joseph DeSisto.

The last two illustrations, you may have noticed, are roughly symmetrical. Real specimens are hardly ever that perfect — to make the illustrations look a bit nicer, and fit better on the page, I traced one half first and then traced its mirror image. In other words, the outlines are symmetrical because each side of the line drawing actually shows the same side of the original specimen.

Here’s a special one. This sexy leg belongs to a male Nadabius aristeus, a common but smaller New England centipede. There are two important features I’m trying to show here. First, there are two claws, rather than just one, at the end of the leg. Second, the hairy crest on the tibia is unique to males the genus Nadabius.

One of the terminal legs of a male Nadabius aristeus. Illustration by Joseph DeSisto.

One of the terminal legs of a male Nadabius aristeus. The tarsus/foot is at the bottom. Illustration by Joseph DeSisto.

Female centipedes be like, damn!

Common Names for a Few Centipedes

by Joseph DeSisto

Few, if any, centipedes have common names. Presumably this is because they are often perceived as being uncharismatic. Here’s why they should get common names:

1) Centipedes are too charismatic.

2) Yes they are.

Below I’ve listed every species of soil centipede known from New England. Soil centipedes belong to the order Geophilomorpha, one of four centipede orders found in North America — so this list is far from complete. I’ve provided a Latin name, a proposed common name, and a brief explanation.

Arenophilus bipuncticeps, the northern short-clawed centipede

Northern because it’s the only Arenophilus found in the northeastern U.S., short-clawed because the claws on its last pair of legs are short and stubby and adorable.

Geophilus vittatus, the diamondback soil centipede

This is one of the prettiest centipedes around, and here in New England, we are lucky because it is also one of the commonest. It is a pale yellow like most centipedes, but with dark diamond-shaped markings running down the back. They are found in a variety of habitats, but are especially easy to find if you peel loose bark off dead stumps and logs.

The diamondback soil centipede (Geophilus vittatus), one of my favorites. You can find this centipede in the northeastern United States by peeling away loose bark from dead stumps and logs. Photo by Tom Murray.

The diamondback soil centipede (Geophilus vittatus), one of my favorites. Photo by Tom Murray.

Geophilus mordax, the pitted soil centipede

G. mordax is a strange centipede, and in reality probably includes two species: mordax in the south and virginiensis in the northern part of its range. For now, though, the two species are united by the presence of pit-like structures (sacculi) on each of the sternites or belly plates.

Geophilus cayugae, the montane soil centipede

According to Crabill (1952) G. cayugae prefers high elevations. Other than that, this species isn’t all that distinct.

Geophilus terranovae, the Newfoundland soil centipede

Here’s a cool one. Terranovae was described by Palmen in the 1950s from Newfoundland, and since no one had recorded it elsewhere, the centipede was assumed to be endemic to Newfoundland. But just this year, I found specimens of terranovae from New Hampshire, so although this is clearly a boreal species, it has a much wider range than previously thought.

Geophilus flavus, the boreal yellow-headed soil centipede

This is one of our largest soil centipedes, an introduced species from Europe. It is also yellow-white, with a darker head, and often found in gardens. This species is common in my home state of Maine but I have yet to find any in Connecticut. I suspect this is because G. flavus prefers a more northern climate, with cooler temperatures and pine-dominated forests.

This name is a little long, but there are a lot of soil centipedes out there. It looks like long names might just have to be the norm.

The venom-injecting fangs of the northern yellow-headed soil centipede (Geophilus flavus). Photo by Joseph DeSisto.

The venom-injecting fangs of the boreal yellow-headed soil centipede (Geophilus flavus). Photo by Joseph DeSisto.

Strigamia bothriopus, the red pin-head centipede

Species in the genus Strigamia are a mix of beautiful, weird, and horrifying. Many are brightly colored, and in New England bothriopus is one of the prettiest, the vivid red hue of a Maraschino cherry. They also have tiny heads, which is sort of adorable, until you learn what they’re for.

Strigamia have an extra claw on their venom-injecting fangs, causing them to look sort of like a can-opener. In function this is not inaccurate, but instead of opening cans, pin-head centipedes use their claws to open up the abdomens of insects. The tiny head can then be inserted into the insect — this way, Strigamia can lap up the nutritious insides of its prey without having to chew through lots of exoskeleton.

Strigamia chionophila, the boreal pin-head centipede

Chionophila is similar to bothriopus, but smaller and less brightly colored. This species is also more common in boreal habitats, gradually replacing bothriopus as the climate cools to the north.

The red pin-head centipede (Strigamia bothriopus). Photo by Tom Murray.

The red pin-head centipede (Strigamia bothriopus). Photo by Tom Murray.

Pachymerium ferrugineum, the long-jawed shore-crawler

This is by far my favorite New England soil centipede, but unfortunately it is one of the least common. The shore-crawler gets its name from the fact that it’s fangs are relatively large for its body size, and that it is often found in the intertidal zone. Beneath rocks and seaweed, it feeds on barnacles, amphipods, worms, and other marine invertebrates. This centipede can even tolerate extended periods of immersion in salt water!

For this reason, I’ve named ferrugineum the “shore-crawler” rather than the “shore centipede.” Shore-crawler sounds cooler, and cool centipedes get cool names.

Schendyla nemorensis, the clawless soil centipede

This centipede is small and inconspicuous, but one of the most widespread soil centipedes in the world. It exists in Europe as well as much of northern North America, where it is thought to have been introduced by humans, but in fact it may have been here long before us. The name comes from the fact that its last pair of legs lack tarsal claws, for reasons unknown.

Escaryus liber, the Appalachian winter centipede

Like all members of the genus Escaryus, this species is highly cold-tolerant and can remain active through the winter, beneath the frost line. I have examined winter centipedes that were caught in pitfall traps as early as January — my suspicion is that this adaptation allows them to feed on defenseless, hibernating insects, giving them a head start in the coming year.

A soil centipede chomps down on an earthworm ... a little ambitious, perhaps? Photo by Tom Murray.

A soil centipede chomps down on an earthworm … a little ambitious, perhaps? Photo by Tom Murray.

Escaryus urbicus, the short-faced winter centipede

In North America, this is the northernmost representative of Escaryus, and the one you would expect to find in New England. In truth, all winter centipedes have relatively short “faces,” and fangs that don’t extend past the front margin of the head. But only one species could have that common name, so this was it.

Obviously nothing about this list is official — I’d love to hear your thoughts on how the names could be improved. Centipedes, like many invertebrates, are nightmarish to many, fascinating to some, and beautiful to only a few. Perhaps by making them more accessible to the public, we can reveal them for what they truly are: awe-inspiring, magnificent, and ultimately beautiful nightmares.