Choosing my favorite millipede

I was asked recently what my favorite millipede is. That's not an easy question, but I was forced to pick one, so I thought about it for a bit and then figured, why not share it with everyone? I find myself doing more tweeting than blogging lately, but Twitter is terrible for long form responses.

There are about 12,000 described species of millipedes, and I've seen maybe 70 of them in life or in photos, so I'm drawing from a limited pool of millipede diversity. Even so, I know of many amazing species. Is my favorite something like the shocking pink dragon millipede, Desmotyxes purpurosea?

Desmotyxes purpurosea from Enghoff et al 2007. Read the paper, it's really neat!

Or maybe my favorite is another tropical millipede. After all, Psammodesmus bryophorus, a millipede I've blogged about before, has mosses that grow on its back!

Photo from Martínez-Torres SD et al 2011.

You won't be disappointed if you browse photos of millipedes from the tropics. There are many forms that are beautiful and seem almost alien, but I'm still biased towards the temperate forms I'm used to. Even among these North American millipedes, I'm not left with boring species. In fact, it's quite the opposite.

California has some of the world's most amazing millipedes. There's this millipede genus, Motyxia, that occurs in only a few counties there. Apparently all the species in the genus weren't content with the fireflies in the western US, which usually don't bioluminesce as adults like they do in the eastern US (there are different species out west). So, they took it upon themselves to pick up the slack, with marvelous results.

The eight species of Motyxia all bioluminesce.

Motyxia sequoiae (a) under normal light (b) bioluminescing, from Marek et al 2011. Read more about this genus here.

Out of all 12,000 known species of millipede, only these ones bioluminesce. Isn't that amazing? Certainly bioluminescence makes for a strong contender for "favorite millipede." But still, it's not quite my favorite. To be fair, my own bias is sneaking in now. I've never had any interactions with Motyxia, so they're still esoteric to me. To find my favorite millipede, I need to go closer to home.

It just so happens that home for me is Ohio, in the foothills of Appalachia. The Appalachian Mountains host an amazing array of diverse millipedes, including many in the family Xystodesmidae. This family features some of the continent's most colorful millipedes, which have a habitat of exhibiting aposematism: their bright and bold colors act as a warning to predators that they have chemical defenses.

Brachoria dentata, a Xystodesmid millipede that displays aposematism. Photo taken by Paul Marek.

Xystodesmid millipedes have mastered Müllerian mimicry. Their color patterns successfully deter predators and confuse taxonomists. Browse around Paul Marek's Tree of Life page on the genus Brachoria and BugGuide's photos of the family and you'll quickly see why: there's a lot of variation in color forms within genera and even within species. They all build on the theme of  black with bright, bold spots of color, resulting in some of our prettiest millipedes. I'm partial to the black and blue species, personally.

After writing around which species is my favorite, I should finally nail it down. As I said, it's not easy. There are so many neat species, and my favorite comes down to one that I found soon after I began studying millipedes. Influenced by my personal history, here is my favorite millipede:

Semionellus placidus, a millipede without a common name. Yeah, that's poop on its back.

Semionellus placidus is a millipede in the family Xystodesmidae. It's classified in the tribe Chonaphini, which has most of its species in the Pacific Northwest of North America, but this one makes it out east. It's sporadic in its occurrence, and I've only found it at one site near my hometown in Ohio, though it's been reported from a few other Ohio counties.

Curled up in defensive position

What's so special about this millipede? It's not nearly as bright and colorful as other Xystodesmids; instead it sports a comparably drab brown and peach-banded color scheme. But it's the memories I have surrounding this millipede that makes it so special.

The first time I came upon this species was during a night hike. I wanted to see what bugs I could find at night, and I had a couple of good friends volunteer to come along with me as I searched. We found some neat insects--including moths and a dragonfly hanging from a tree--but the best find of the night came when I turned on the UV flashlight I had brought along. I shined the light over the leaf litter, and to my surprise, I found many small millipedes moving amongst the leaves like tiny trains, shining an ethereal blue-green under the UV light.

Semionellus placidus under UV light

I had heard about millipedes that fluoresce under UV light before, but this was the first time I had seen one for myself. (Note that UV fluorescence is different from bioluminescence. Fluorescent millipedes don't produce their own light, they just fluoresce under the UV light source, but stop when that source is taken away. The bioluminescent Motyxia millipedes, on the other hand, produce their own light.)

Semionellus placidus (left) under natural light (right) under UV light. Photo by Dave McShaffrey and featured in UV fluorescing millipedes from southeastern Ohio

It was exciting to witness, almost like I was watching something secret. The millipedes don't stand out in the dark at all; I didn't see them until I turned on the UV light. I was intrigued, so of course I collected some to take back to the lab. That was the first time I was really exposed to identifying millipedes on my own. This was during fall of 2011, and a few months before I had attended a millipede identification workshop taught by Bill Shear, where I learned the basics of millipede identification and obtained some print references I needed to identify millipedes. 

I did the best I could and narrowed it down to the order Polydesmida and family Xystodesmidae, a big accomplishment for me at the time. I didn't have a key to Xystodesmid genera, so I turned to BugGuide, where I uploaded a few photos. Rowland Shelley pointed me to Semionellus placidus, and I was able to confirm the ID by looking at a male's gonopods and comparing it to old literature records that had pictures of the gonopods. 

It was beyond fulfilling to identify this millipede at last. I learned a lot about millipede identification from the experience: the importance of collecting a few individuals (and hoping to catch a male), which features are useful for identification, the necessity of going to the experts, and the legwork it takes to track down scientific literature on millipedes, much of which is old and the only source to find information on some species. It took many hours, but was well worth it. Being able to identify your local species, whether they're flowers, birds, insects, or millipedes, is a powerful feeling.

I realized pretty quickly that there isn't much information on millipedes that is accessible to the general public. Millipedes are difficult to identify, they're not immediately showy and beautiful like butterflies, and there aren't many scientists researching them, which puts up more barriers for someone with an interest in millipedes. Essentially, unless you're someone who already studies Entomology, you're not going to have an easy time learning about millipedes, and that's a shame.

Due to this, I've taken it upon myself to do what I can to make millipedes more accessible to the general public and altogether more compelling for people to pay attention to. Most of my millipede projects have grown out of finding Semionellus placidus and working with the species.

"What's your favorite millipede?" As I thought about the question, it became clear that bioluminescence and bright colors are cool, but there's no way they can surpass the learning experiences I gained from finding an inch-long millipede in the woods.

References:

Enghoff, H., Sutcharit, C. & Panha, S. 2007. The shocking pink dragon millipede, Desmoxytes purpurosea, a colourful new species from Thailand (Diplopoda: Polydesmida: Paradoxosomatidae). Zootaxa 1563: 31-36.

Marek P.E., Papaj D.R., Yeager J., Molina S. & Moore W. 2011. Bioluminescent aposematism in millipedes. Current Biology 21: R680–R681.
Martínez-Torres SD, Flórez Daza ÁE, Linares-Castillo EL. 2011. Meeting between kingdoms: discovery of a close association between Diplopoda and Bryophyta in a transitional Andean-Pacifc forest in Colombia. In: Mesibov R, Short M (Eds) Proceedings of the 15th International Congress of Myriapodology, 18–22 July 2011, Brisbane, Australia. International Journal of Myriapodology 6: 29–36. doi: 10.3897/ijm.6.2187

A Primer on Ohio Millipedes

23 May 2021: An update

 

Hi there! It's been 8 years and a few days since I wrote this post, and enough has happened that I felt like I should update it. Here's the big news: there is now a guide to the millipedes of Ohio! I worked with my colleague Jeff Brown on a guide for the Ohio Division of Wildlife's Ohio Field Guide series, and you can find the finished project here: Millipedes of Ohio Field Guide.

 

The field guide includes color photos and information for 51 millipede species you can find in Ohio and also includes information on centipedes, pauropods, and symphylans. The guide also includes information on how to find millipedes, their habitats, their predators, and more. It contains much more detail than I included in this blog post, and I hope it's helpful for your own personal millipede journey. It's also the first field guide to millipedes in the US ever, which I'm very proud of. Be cautious when using it to identify millipedes outside of Ohio, however: many other genera and families occur in other areas of the US, and it's likely that your local species will be different than the ones discussed in the guide.

If you'd like to learn more about the creation of the guide, I gave a talk about it at the 2021 Ohio Wildlife Diversity Conference, which you can watch on YouTube.

 

 Below is the original blogpost.

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Millipede - Abacion sp.

I've been doing some research lately on a few millipede genera and have found myself lamenting the lack of well-written and accessible resources for millipedes. I have a good enough knowledge base to navigate through the published literature, but it's too inaccessible for general audiences. BugGuide's millipede page is probably the best online resource, but it still lacks good introductory resources for people wanting to learn more about the many-legged critters. You're able to submit a picture, and if you're lucky, someone will help you get it down to genus and maybe tell you how they identified it.

Concise keys for the millipedes don't really exist like they do for other arthropods, due to the characteristics used to identify millipedes. It's not like identifying a moth or a beetle, where coloration, pattern, and overall look can go a long way. You can get to Order from a photograph relatively easily with millipedes, but any deeper can be a problem without (1) very detailed photos or (2) the specimen in hand. If you're interested in taking a millipede down to species, you're most likely going to need a microscope, because at that point they're identified by the male gonopods (sexual structures). If you have a female, you'll probably have to settle for genus.

But to get to that identification, you'll need the help of a millipede expert (starting off, at least). There aren't all that many out there, and not many amateurs focus on millipedes. Instead, most beginners opt for flashier species like dragonflies or butterflies, groups which have wonderful field guides already published.

To break down a few of the hurdles that stop people from learning about millipedes, I've been gathering together some nice photos and information about my local millipede species to share, one of my goals for this blog. So far in this post, you've seen a millipede in the genus Abacion (Order Callipodida: Family Abacionidae) crawling around on the ground. I found this specimen last week in some wood frass at the base of a dead tree. I haven't keyed it out, but I'm 85% sure about my identification (Long millipede, dorsal crests, etc.). I found a similar millipede last summer, so now I know these guys can be found in the eastern and western parts of the county. I'm not sure if I'll get it down to species anytime soon since even I'm lacking resources for this genus, but it's fine for now.

I originally meant for this post to simply cover the new Abacion specimen I caught, but I can't just complain about the lack of millipede identification resources without trying to fix it...so I might as well post my other local species too! Maybe this will help other would-be millipede enthusiasts get started. You can find some more info in my previous posts about millipedes, such as Mushroom & Millipede Hunting and A Calm Millipede's UV Fluorescence. These images were all taken in southeast Ohio, but these millipedes occur in many other states in the eastern US.

We'll start off with the easiest millipede to identify: Narceus americanus (Order Spirobolida: Family Spirobolidae).

Curled up in defensive position.

This species is actually a species complex referred to as the Narceus americanus-annularis-complex, since the two species aren't taxonomically differentiated yet, but that's a technicality that I'm going to ignore for now because it's not helpful for beginners. This millipede can grow up to 4 inches long, making it the largest millipede you're likely to see in the eastern US. It can live up to two years, as I found out when I kept one as a pet. Like most millipedes, it feeds on dead leaves and other detritus on the forest floor, and it can be found under the bark of logs and by turning over the leaf litter from spring through fall.

I've often posted about the above species: Semionellus placidus (Order Polydesmida: Family Xystodesmidae). It exhibits fluorescence under UV light and can also be found in leaf litter. It's about 1.25 inches long and is mostly brown with pinkish-orange stripes on the sides and back of its paranota (the extensions on its back). This species has a wide range in the eastern US, but occurs sporadically. The easiest way to find it is to go out at night with a UV flashlight and shine it over fallen leaves in a forest. If you refer to my second blog post I linked to above, you can see photos of what it looks like under UV light and photos of the male's gonopods.

 Another common species I see is Pseudopolydesmus serratus (Order Polydesmida: Family Polydesmidae), a pretty pink millipede about the size of Semionellus placidus. It can be found under rocks, under the bark of dead logs, and in leaf litter, so it's cosmopolitan in its habitat as far as millipedes go.

Its legs look very needle-like as they taper down to the millipede's feet. Its paranota taper back more on the segments closer to the millipede's posterior.

One of our prettiest millipedes is Euryurus leachii (Order Polydesmida: Family Euryuridae), which may also be the one millipede you can set out to find when you go into the woods. I've always found it in decaying logs, but it can also be found in leaf litter sometimes. (Still though, if you for sure want to find this species, just peel back the bark on a dead log.) Its main body color is purplish-black, with orange spots down its back and on its paranota. It's another that fluoresces under UV light. This species and the previous two are all in the order Polydesmida, which includes many UV fluorescent species--always keep your black light in your insect bag! Don't be too hasty with identifying this species from photos, however: the similar-looking Auturus evides is tough to separate unless you know your stuff.

Here's another entry for the Polydesmida: the Xystodesmid millipede Apheloria virginiensis corrugata. This is a rather large millipede, with a length of about 1.5 inches, and its body is quite broad. It's another UV fluorescent species, though the fluorescence is mostly limited to the underside of its body. The yellow and black coloration is a warning to predators: like many other millipedes, this one has chemical defenses. This species can emit cyanide in response to an attack, so it's not recommended to pick it up. That's not to say it's very dangerous if you do--just wash your hands afterwards. Interestingly enough, I recently found three individuals of this species: two were dead from drowning in puddles after a rain, while the other was waltzing around in some leaf litter. They were all near the same location, and I was surprised to find three in the span of about 16 hours. Usually I have to go hunting for a while to find them. Note that this species has many look-alikes, especially in the Appalachian mountains. There's a good amount of variation even within the species, so remember that this is just one subspecies of Apheloria virginiensis.

And now it's time to introduce a few less photogenic millipedes. The above species is in the genus Cleidogona (Order Chordeumatida: Family Cleidogonidae) and is small compared to the previous species in this post. The first photo doesn't show its exact features terribly well, but it shows both its size in reference to dead leaves and its colors during life. Its body is brown with white spots poking through, and it has short setae along its back. The close-up in the second photo is a dead specimen after being preserved in ethanol.

Next up are a few non-native species.

The first is Ophyiulus pilosus (Order Julida: Family Julidae), an imported species from Europe. It's usually found in yards rather than forested areas, but the specimen I've found was collected from leaf litter in a forest in late fall. It's a slender dark brown/black millipede, and its epiproct is useful for identification: that's the part at the end of the body that looks like a pointed tail (blurry in the first photo).

Another non-native species is the ubiquitous Greenhouse Millipede, Oxidus gracilis (Order Polydesmida: Family Paradoxosomatidae), imported from Asia. It's common throughout the US, and can be recognized by the transverse grooves on its back. It's a thin millipede about an inch long, and can usually be found mating. You've probably come across this species if you've done some gardening or turned over a rock or two in your yard. I personally am sick of seeing this millipede all over the place.

I've included some diagnostic characters for identifying these millipedes, but keep in mind that for most millipedes, you'll need to use a microscope to positively identify them. Some are distinctive enough to identify just from a photo, but even then you can get look-alikes (such as Euryurus and Auturus). However, once you become accustomed to working with millipedes and spend some time identifying your local species, it gets easier. For now, these are photos that you can trust are identified correctly--that's better than what Google will give you.

For more resources on millipedes, check out BugGuide's Millipede Hub, which is the most accessible online resource for millipedes. Rowland Shelley, who frequently helps to identify millipedes on BugGuide, has a nice collection of millipede photos on his site here. That is a resource you can DEFINITELY trust, Shelley is a world expert on millipedes. For published literature sources, you can find older articles about millipedes by searching through the Biodiversity Heritage Library, a wonderful site that has provided me with a ton of primary literature on millipedes--which is often where you need to go for keys, illustrations, and general biological information. Milli-PEET is another site with useful information, including a good key to order for millipedes. Milli-PEET is a project that was funded by the National Science Foundation, with the goal of making millipede research more accessible and succeeded in reaching that goal.

EDIT (6 November 2013): The Myriapoda Flickr group is also a great resource, with many gorgeous photos of millipedes and other Myriapods.

I hope that this post is helpful to those of you interested in learning more about millipedes, and that it inspires you to start taking photos of the millipedes in your area, wherever that may be. The millipedes are in the taxonomic class Diplopoda (that's a taxonomic position on the same level as the Insecta, which we definitely devote a lot of research to), and that includes about 10,000 species, with many more to be discovered. Millipedes are important organisms for nutrient cycling in terrestrial ecosystems, yet they're criminally under-studied. The best way to change that is by making it easy to break into millipede research, so why not start at the most basic level? People need to have the resources to identify these organisms, and photos are some of the best sources for identification (even with their limitations for millipede taxonomy). If nothing else, they can help people get a better feel for the overall "look" of different millipede taxa. So get out there and start trying to identify your local millipedes. Take some photos, put them online, and let's give some names to our many-legged friends!

Of course I had to include a photo of millipede UV fluorescence! Not all millipedes exhibit it, but the ones that do look spectacular.

Mushroom & Millipede Hunting

Yesterday was a nice day outside, and I figured it would probably be one of the last before the snow started falling. I decided to take advantage of this, and set off to find some mushrooms. (Also, it was snowing when I woke up this morning, so I was correct in my assumption. Maybe I should take up weather forecasting.)

I packed some collecting supplies and set off for the nature trail near my old elementary school. It has a nice array of habitat types and gratuitous amounts of decaying logs, so I was optimistic that I would find some nice mushrooms. However, almost immediately after I stepped onto the trail, my trip turned into millipede hunting. It's just too difficult to resist turning over every decaying log I find in hopes of getting some millipedes out of it.

My habit ended up paying off: I found many millipedes and collected 7 specimens from 4 separate species. It's astounding how many little critters live in decaying wood and the surrounding leaf litter. It's a miniature rain forest in there, but is often overlooked. It's really quite easy to collect arthropods using leaf litter: take a few fistfuls of leaf litter and maybe a little dirt, stuff it into a plastic bag, and later transfer it into a funnel. Put a light bulb above the funnel and a jar with some alcohol underneath the funnel, and give it a few days. All the arthropods will dig down through the leaves and fall into the jar. Put your catch underneath the microscope and you'll see all kinds of spiders, pseudoscorpions, harvestmen, millipedes, insects, mites, and so much more.

Though my excursion focused on millipedes, I did eventually incorporate fungi as well.

Another mysterious fungus, along with a millipede.

I rooted through the leaf litter near a dead log and turned over this old piece of bark. The fungus caught my eye long enough to distract me from the millipede (which I did catch later). It reminded me of another fungus I saw a few summers ago and blogged about here. I'm still at a loss for what they could be and need to find a good resource on fungi to research it more. I poked one of the drops and it ran onto the wood, into which it was readily absorbed.

The millipede ran surprisingly quickly, as they're usually slow. It didn't try to curl into a spiral when I picked it up, but rather thrashed around a bit instead. This is atypical for millipedes, which was intriguing. I think it's a Chordeumatid in the genus Cleidona, but I'll need to get it under a microscope and look at a few features before I can be sure.

The other millipedes I found were much more millipede-like in their habits. The most abundant millipede I found was a Polydesmid that I've found a few other times, but have yet to identify. 

Crawling around its new home, a nice plastic container I prepared.

It looks similar to another millipede I've seen before, Pseudopolydesmus serratus, though it doesn't fluoresce under UV light. I grabbed three specimens, and one is a male, so I should be able to figure it out.

After turning over enough decaying logs, I've learned which millipedes I can expect to see more often than not. And like usual, the beautiful Euryurus leachii, showed up under the logs I looked at.

This millipede is a little over an inch long and is easy to recognize. It has a blunt epiproct (its "tail"), separating it from other Polydesmids. The orange spots along its back and at the edges of its paranota, combined with the purplish hue of its body, readily identify this native millipede. It's certainly in the running for most beautiful millipede in Ohio. Once you cross into the central US, however, be careful: Auturus evides is a lookalike. I haven't seen a specimen of A. evides for myself, so I'm not yet sure how to differentiate them.

Another reason for E. leachii's beauty: its fluorescence under UV light.

Not to be outdone by all these amazing millipedes, the fungi made a comeback somewhere around the Soggy Bottom Trail.

It's usually much soggier. 

Decaying wood isn't only for millipedes, it's also great habitat for moss and mushrooms!

Those little brown mushrooms made a cute little home in a hole in the log, flanked by moss. If you look closely at the stalks coming up from the moss, you can see the calyptra (the green sheath) around the spore capsule. Think of the calyptra as a protective blanket keeping the capsule safe until it's time to let the spores go. If you look in the background, you'll also see a polypore coming out of the log...

The Soggy Bottom Trail did not disappoint!

The Glowing Eggs of Semionellus placidus

When I need to talk to someone about a facet of Entomology that blows my mind, I've taken to mentioning millipedes. I've been keeping millipedes as a labor of love over the past year, which is something that has taught me a lot. Probably the coolest thing I've learned about is some species' propensity to fluoresce under ultraviolet light.

I've chronicled my previous experiences with a millipede species that fluoresces under ultraviolet light previously here and here, so if you want a primer about Semionellus placidus, check out those posts. I've established that this species fluoresces under UV light quite nicely, and I've found it in the field from spring until fall. It also appears to be quite abundant (in southeastern Ohio, at least) and lights up the leaf litter whenever I'm looking for it.

UV fluorescence in arthropods isn't anything new: it's been reported most notably in scorpions, many insects, and some other millipede species. A few months ago, however, I found something new: UV fluorescence in the eggs of Semionellus placidus. I haven't found other mentions of this, and the literature I've read has shown the fluorescence in post-egg stages, chalking it up to chemicals in the exoskeleton.

Needless to say, this is pretty neat. I'm currently keeping some of the eggs in a separate container, hopefully to hatch them out. I'm not sure how that will turn out, however, as I recently checked on them and it looked like a fungus got to them.

Under normal light, the eggs don't look like anything special, as you can see below.

Now, time to investigate this further...

A Calm Millipede's UV Fluorescence

Let's talk about millipedes! You may have read my entry on a millipede that fluoresces under ultraviolet light I found this past fall that grabbed my attention. I've since done some more research, and after working on a poster a few weeks ago for the Ohio Natural History Conference, I have more information and motivation to summarize what I've learned.

How did I find out about these UV fluorescing millipedes in the first place? I was on a night hike with some friends last fall and had the foresight to bring a UV flashlight along, just in case there was anything neat to look at under UV. It was a bit chilly, and we weren't finding much.

Then I turned the flashlight on.

As we passed by areas with fallen leaves, I started catching glimpses of blue-green light: millipedes were fluorescing while milling about in the leaf litter. If you haven't seen this, you owe it to yourself to grab a UV flashlight and check it out. As it turns out, the millipedes I was seeing were one species: Semionellus placidus. This millipede is in the family Xystodesmidae and is about an inch and a quarter long. Many Xystodesmid millipedes are known to fluoresce under UV, and one genus contains the only bioluminescent millipedes known to exist (note that bioluminescence, when an organism produces its own light, is different from UV fluorescence).

I was intrigued by this millipede, but didn't know anything about it at that point--not even its species. I keyed it out to family with the help of an unpublished key by Bill Shear, and posted it to BugGuide, where Rowland Shelley helped me with the species. It's in the tribe Chonaphini, which is mostly restricted to the Pacific Northwest. Breaking the mold, Semionellus placidus ranges from "Minnesota and Michigan east to New York, south in the mountains through Maryland and Virginia to Fort Benning, Georgia" (Chamberlin & Hoffman). It is also described as sporadic in its range, rather than blanketing it uniformly.

 S. placidus under low UV light.

S. placidus under normal light.

I finally had my ID for this species! I started checking the literature to find out more and discovered....there's not much published on it. Oh. To make sure I wasn't missing any hidden information anywhere, I did a thorough job of Googling my enigmatic millipede, which turned up some old publications that are a little difficult to interpret. It's that 100 year gap in English, you know? My research is also made trickier by the synonyms this species has. Here's the list:

• Chonaphe michigana 
• Leptodesmus borealis 
• Leptodesmus placidus 
• Polydesmus floridus 
• Polydesmus placidus 
• Trichomorpha placida

Millipedes don't have the same PR and research dollars behind them as a group like the butterflies (big insects, pretty colors and all that jazz), so that leaves me in the position of doing the research myself. Of course, that's exciting! I have a figure of the male gonopod hanging up on a board in the lab (see below), with the main things known about the millipede written beside it in dry erase marker as motivation for delving deeper.

Figure 1 from "Some Records and Descriptions of Diplopods Chiefly in the Collection of the Academy" by Ralph V. Chamberlin. (Currently hanging up in my lab.)

Let's take a moment to talk about the above picture, Figure 1. You'll notice that number 3 is what we're interested in: that's the gonopod of Semionellus placidus. The gonopods are a pair of modified legs the male millipede uses during mating for sperm transfer to the female. These structures can be pretty elaborate and sometimes don't look like anything that ever could have been a leg. To really get a feel for what the gonopods look like, check out the three pictures below.

Millipede flipped on its back, camera looking down at the gonopods.

 Same as before, but the millipede has been turned slightly to get a side view. The gonopod on the right was overlayed from a picture with better focus.

Side view.

I've successfully kept some of these millipedes I collected from the field station alive since October, and a few females have laid some batches of eggs in their container. The eggs fluoresce under UV as well, which is pretty neat. They're laid in a soil cavity, which the mother excavated at the bottom of her plastic container about 1.5 inches down. UV fluorescence in a life stage other than the adult hasn't been reported before, so that observation might be important in figuring out why/how the millipedes fluoresce.

Next steps:
It's time to do some research! With capstone looming ever closer on the horizon, I must devote my research time to finishing that, but I'm hoping to hit the field station during the summer with a UV light to see if this millipede is active yet. I've encountered it during September and October, but so far that's it. I'm also going to work on some type of publication based on what's known, and I'm waiting for another reference to come in. If my plans work out and I'm available during the summer, I hope to try to observe the assassin bug Rhiginia cruciata's relationship with this or any other millipede to quantify its feeding habits. (Remember: R. cruciata is an assassin bug in a subfamily known to feed on millipedes.)

A dish of millipedes under UV light. Most of the ones fluorescing in blue are Semionellus placidus, while the two fluorescing red are Pseudopolydesmus serratus. Red fluorescence under UV hasn't been reported before in arthropods, to my knowledge.

References:

Chamberlin, RV. 1920. A new leptodesmoid diplopod from Louisiana. Proc. Biol. Soc. Washington, 33: 97-100. Link.
Chamberlin, RV. 1947. Some Records and Descriptions of Diplopods Chiefly in the Collection of the Academy. Proceedings of the Academy of Natural Sciences of Philadelphia, 99: 21-58.
Chamberlin, R.V. & Hoffman, R.L. 1958. Checklist of the millipeds of North America. Bulletin
of the US National Museum, 212: 1–236.
Wood, HC. 1864. Descriptions of new species of North American Polydesmidae. Proc. Acad. Nat. Sci. Philad, 16: 6-10. Link.

My First Research: Assassin Bug and Millipede Invasion at the ONHC

My posters from the Ohio Natural History Conference are now online! I've updated my post from the conference with links, and also wanted to post them here for easy reference. I was the lead author on my first poster, "A Biological Survey of the Assassin Bugs (Hemiptera: Reduviidae) at the Barbara A. Beiser Field Station", which is posted below. Click this link or right click on the picture and choose "view image" for a larger (and readable) picture.

I was a contributing author on the second poster, titled "UV Fluorescing Millipedes from Southeastern Ohio." There's a lot of interesting questions raised from this research that I would like to investigate. Hopefully it will inspire others to take an interest in millipedes as well.

Note that there is a typo in the first paragraph of the Conclusion section. E. leachii is always found in decaying wood, not in leaf litter.

For more information about the conference, you can read over my first blog post (which has a link to my tweets from the conference), and some news stories from my college here and here.

This Isn't Your Father's Daddy Longlegs

While on a night hike looking for fluorescent millipedes and whatever else I could find a few months ago (September 16th), I came across a most interesting arachnid. Now, it's important to note that Arachnids aren't just spiders: Arachnida is a large class that includes other organisms like scorpions, ticks, mites, solifugids, and harvestmen (or daddy longlegs, if you prefer). It's the harvestmen (Order Opiliones) that are most important to this post, and while the popular perception of harvestmen is a small-bodied organism with long, thread-like legs, this is not always the case.

There's a surprising amount of diversity in the harvestmen: it includes 6,411 described species (estimates of over 10,000 total species have been put forward!) and 45 families. After spiders and mites, it's the third largest order of Arachnids.

Which brings us to the specimen found on that cool September night:

Not exactly what you were expecting, eh?

This is probably the largest harvestmen I've encountered, and it's definitely much different from the other species I've seen. From what I can tell, this is a species in the genus Vonones, in the suborder Laniatores (we'll tackle the significance of that later) and the family Cosmetidae. I'm a fan of the colors on this one, the red, brown, and yellow blend nicely together.

Was I hesitant to pick up this harvestmen at all? Nope--harvestmen don't have venom glands! I scrambled to catch it before it could get away, as I had just lifted up a stone. I screamed, sure, but that was a scream of joy, not of fear: I had found this neat organism, AND an assassin bug as well!

  Black Corsair - Melanolestes picipes

An assassin bug along with an interesting harvestman? TOTAL SCORE! There's some interesting life hiding under stones, so I made a mental note to add that to my routine while walking through the forest. I had been checking stones before, but this was one of my first night hikes, giving me the chance to find different organisms.

Unfortunately, I haven't been able to find too much information about Vonones, but I'm still searching. One odd piece of information I've come across is that they fluoresce under UV light, according to this thread on Arachnoboards. I'll be checking that out next time I encounter one.

 What secrets do you hold?!

I mentioned earlier that there's a significance to Vonones being in the suborder Laniatores. It seems as though harvestmen in this suborder exhibit paternal care for eggs after they are laid--unique in the Arachnids, and restricted to this suborder. It would be interesting to investigate if this behavior holds true for Vonones, and how it affects survival. Perhaps daddy longlegs are more loving than you first thought...

References

Beccaloni, Jan. 2009. Arachnids. Berkeley: University of California; 320 p.

Fluorescent Millipedes? Sweet!

Just a quick post here to highlight one of the more interesting things I've found lately: millipedes that glow under UV light. I've been busy with my Investigative Studies Project, Capstone, and other related endeavors, so I'm essentially stockpiling a lot of photos and information for blog posts during winter, when I won't be finding nearly as much arthropod stuff.

You think you have to go to the rainforest to find neat stuff? HA!

I took a UV flashlight out to the field a few weeks ago and looked through the leaf litter--it was crawling with these many-legged critters. I could barely contain myself, it was just so neat. There were a few species fluorescing under the light, which is a result of a chemical in their exoskeleton, and the fluorescence was at bright as firefly bioluminescence. 

The millipedes were a nice size, hovering around one inch, and had chemical defenses. I grabbed a few to hold in my hand and could smell a slightly sweet scent on my palm after I returned them to the leaf litter. Chemical defenses, UV fluorescence....will millipedes ever stop being exciting? Nope.

Update (Jan 7, 2012): This millipede is Semionellus placidus, which is in a tribe that occurs mostly in the Northwest of North America. I'll try to gather more information and put that together for another post.

One of my next projects? Research the relationship between assassin bugs of a certain subfamily (Ectrichodiinae) and millipedes. Why? Some species in this subfamily are known to be millipede hunters. Maybe this holds true for our local species as well. The only genus around here in the subfamily Ectrichodiinae is Rhiginia, and I had the pleasure of finding the species Rhiginia cruciata during early summer. That gives me a good six months to prepare. Perhaps the millipedes have some dangerous predators to watch out for.

Scarlet-bordered assassin bug, Rhiginia cruciata. Millipede hunter?