December's Centipede

Ohio's had a warm December so far, and I have only seen a few snowflakes here in southeast Ohio. This week has been moderately warm, with temperatures in the high 40s and low 50s (Fahrenheit, that is). We've had a few cold snaps, so I've pretty much stopped looking for any arthropods, except for lady beetles and marmorated stink bugs in my home.

Then I went outside to retrieve the mail today. I spotted something moving on the porch and took a closer look: it was a centipede! I ran inside to retrieve a vial, almost falling in the hallway due to my wet shoes (it rained today) and frightening the cat, which ran into the living room. I apologized and ran back outside, just in time to catch the critter before it left the porch and disappeared into the yard.

I took it back inside and examined it: it was one of the largest centipedes we have in Ohio, Scolopocryptops sexspinosus. It's in the family Scolopocryptopidae and only has 23 legs--not 100 (no centipede has 100 legs, despite the common name for the group). Normally this centipede is found under logs or rocks, so I was surprised to see it crawling around. Perhaps the soggy ground sent it searching for a drier place?

This centipede is a whopping 2.5 inches long, which is intimidating the first time you see it. It does have venomous fangs (which are actually modified legs!), so be wary of picking it up. Its bite isn't life threatening, but it probably won't feel very nice either. There is a similar species, S. nigridius, that occurs in the eastern US, but it's less common than S. sexspinosus. S. nigridius is reported to be darker with a bluish hue, though I've yet to find a specimen myself.

This individual is currently settling into its new home--one of my insect cages. I'll nab a few more photos and then decide what to do with it afterward. One of the things I've noticed while keeping it is its response to light. It has ocelli (small eyes that detect light and dark) on the sides of its head, and whenever it senses light, it scampers away and tries to burrow under anything nearby. This reveals another of its traits: speed. This species (like most centipedes) is fast. It's like a cheetah with a lot of legs.

So how do you know when you have this species? If you're in the eastern US, your centipede has 23 legs (putting it in the family Scolopocryptopidae), is bright orange and usually 2 or 3 inches in length, then you've got yourself a Scolopocryptops sexspinosus.

Neglected Collections

After my college graduation last May, I've been using my free time to go back through the bug collections I did while still an undergraduate. I had a lot of material left over--both dry specimens and ethanol specimens, along with photographs and lists to organize. I never quite had the time to do it while taking classes (or at least, that's what I tell myself), so I'm very glad I can take care of it now.

I've had this blog post about respecting your specimens gnawing at me since I read it during the summer, and felt a bit guilty. I had some pretty crappy labels with my specimens, or even worse, no labels at all! For some, I could remember exactly where I was standing when I collected them, so it wasn't a huge problem. But for others...well, those just had to be thrown out as useless.

Some of my specimens were new to the collection and represented unique information, so I wanted to make sure they were properly labeled and taken care of. With that mission in mind, I've devoted myself over the past month to slogging through my material that's been languishing for months (in a few cases, years). And now, I'm beginning to see results!

This box only has six empty spots now.

I've prepared labels for 90 specimens and put many of them under the microscope to identify them as close to species level as I could. This was difficult for a number of them, especially the centipedes, due to lack of practice by me and the lack of recent references, but it's been a fun challenge. I've also found some interesting animals (such as the centipede Theatops, the subject of my previous blog post) and experienced some great memories. Most of my millipedes were collected for a Field Techniques class with the help of two good friends, who spent their evening sampling through leaf litter with me. A scorpion was collected during a summer class in the New Mexican desert, where I learned about arthropod UV fluorescence for the first time.

Now I'm at the point where I can do something with all my collected specimens. Some of what I'm working on includes:

• A guide to Ohio centipedes, which will be accessible online and will have pictures of certain identification characteristics to make up for the paucity of reference material online.
• A publication of my assassin bug research
• A publication/guide of local millipede species

It's exciting to put together what I've been working on for the past few years, and to find new projects. I'm hopeful that what I'm doing will be useful for others interested in these groups in Ohio. There definitely hasn't been much done with centipedes and millipedes, which is a barrier to anyone wanting to learn more about them or do their own research, so maybe this can be a springboard for future studies.

My to-do list: keeping me going. That "hola" has been there for a while, so I couldn't bring myself to erase it.

Entomological Smackdown

"Yet the law of priority compels its adoption, and one's regret is perhaps to a certain extent lessened by the satisfaction derived from abolishing a name so ill-formed and so ill-sounding as Opisthemega." -R.I. Pocock

The above is taken from a manuscript clearing up confusion about the genus Theatops, which includes a few large centipedes with surprisingly fat terminal legs.

It's burying into the ground here, with the terminal legs trailing at the top of the picture. Yes, it can pinch with them.

There are many hidden gems like these in scientific publications, and it's always a joy to come across them. You're reminded that the entomologists writing them are people too. And I must agree, Opisthemega is a terrible name.

Reference:

Pocock RI. 1888. Annals And Magazine of Natural History. 1:283-290. Link.

This centipede is so happy!

Quick! Describe centipedes in one word!

You said "optimistic," right?

Because the face on the back of this centipede's head is super happy, even when suspended in ethanol. This is a centipede in the genus Strigamia, collected last October from leaf litter when I was searching for millipedes. I wonder if other species have different faces...

Science Video Friday - A Centipede's Song

It's time for a musical Science Video Friday, courtesy of a fan of house centipedes, Scutigera coleoptrata. I was very pleased after I found this video--not only is it about our many-legged friends, but it's very good and catchy. I sometimes find myself singing it from time to time. And some of the photos he features are pretty cute.

A Strange Place for a Centipede

I had an unexpected encounter with a centipede today around lunchtime. I walked into the restroom and glanced down at the floor, where I found an inch-long centipede....and I was pretty excited. Unfortunately, it was dead, probably due to being stepped on. If nothing else though, that made collecting it easy for me. Have you ever tried to catch a fleeing centipede? They're ridiculously fast and not an easy catch.

After putting it in a plastic bag for safekeeping and eating some lunch, I headed off to the lab, grabbed my centipede ID guide, and threw it under a microscope.

It's a little intimidating, measuring out to about an inch long.

Earlier this summer, I attended an advanced naturalist workshop at the Edge of Appalachia preserve in West Union, Ohio that focused on the centipedes and millipedes (and isopods), which gave me the skills I needed to tackle Myriapoda identification. It was led by Bill Shear, from Hampden-Sydney College in Virginia, and boy did he know a lot about the Myriapods. He was kind enough to hand out some ID guides, which is what I've been using since then to figure out what all these leggy creatures are.


I'm always impressed with what I see when I put a centipede under the microscope. There are so many little structures that you completely miss out on until you magnify them, and they're super interesting. It's almost like you're looking at an entirely new animal.

That's a lot of legs. Centipedes have one pair per segment, while millipedes have two pairs per segment.

This centipede has 15 pairs of legs, and even more antennae segments--more than 35 (I haven't been able to get a final count yet). Not all of its legs are there: a good number broke off, including some of the posterior legs, which are important for identification purposes. An interesting fact: centipedes always have an odd number of leg pairs.

A close-up of the centipede's maxillipeds, which have fangs on the end of them that inject venom. You can see an oval outline on the left side of the maxilliped, which I believe is the centipede's venom gland.

Centipedes are predators: they're quick, and they also have fangs. These fangs are found at the end of the centipede's maxillipeds, which are actually a pair of modified legs (whoa!). The venom glands are contained within these maxillipeds, and work in short order to paralyze and kill its prey. Generally, a bite from a centipede from North America won't hurt too much since they're relatively small compared to a human. But there are some species in the southwestern United States and Mexico that are more dangerous, such as those in the genera Bothropolys, Lithobius, and Neolithobius, which are large centipedes.

The fangs and coxosternal toothplates, with teeth.

Due to the rough shape this centipede was in when I found it, I haven't been able to nail down its ID further than Family Lithobiidae. Currently, family designations for the Order Lithobiomorpha are in flux, with only two families officially recognized--Lithobiidae and Henicopidae. There's definitely room for improvement, and the group is waiting for someone to tackle it.

 Ventral view of the centipede, with coxal pores circled.

An interesting part of centipede anatomy (and a useful characteristic for identification) are the coxal pores, located at the bases of the posterior legs. These pores are connected to coxal glands, which are used for nitrogenous waste excretion.

Make sure to be on the lookout for centipedes and millipedes where ever you are: once you start looking, you'll start seeing them everywhere. The world of the Myriapods is surprisingly vibrant: chemical defenses, parental care, and even bioluminescence characterize many species. It would be a shame to ignore it.

References:

Shear and Weaver. 2007. Keys to the Centipeds of Virginia and Adjacent Regions.

Centipede Anatomy (Scolopendromorpha)

Centipede - Wikipedia