Millipede Mystery

My millipede research always seems to throw me into new adventures. Neat information just sort of hangs out in the old literature, sometimes in the form of a new species that no one is quite sure about.

The species in question is Chaetaspis albus. Sort of. First, we'll go over the information we have about this species.

Chaetaspis albus (no common name, sorry) was described by Charles Harvey Bollman in 1887 (Entomologica Americana, II, 1887, pp.45-46). It's a millipede in the order Polydesmida and family Macrosternodesmidae. His description was also included in an 1893 publication of his works, which is great, because that means I can post the whole thing here without having to worry about copyright. If it's tough to read, you can click the photo to enlarge it.

From Bollman 1893

So there's our information on the original specimen. It's white, less than a centimeter long, less than a millimeter wide, and was found in Indiana under a log. That's a millipede that's easily missed, but it was later found in Arkansas, Kentucky, Tennessee, Alabama, Mississippi, and Virginia as well.

Now we come to the real mystery. In 1928, Stephen Williams and Robert Hefner published The Millipedes and Centipedes of Ohio in the Ohio Biological Survey Bulletin. In it, they noted a few specimens of C. albus from Washington and Athens Counties which were much larger than those in Bollman's description. Williams and Hefner noted the species from the two counties was 15mm long and about 1mm wide, quite a difference from 6-7.5mm long and 0.3-0.5mm wide. Reluctant to declare a new species based on size alone, they left it alone with an acknowledgement that it was strange.

 Williams and Hefner, 1928.

Fig. 12, with gonopod of Chaetaspis albus? outlined in black. Williams and Hefner, 1928

It was an oddity that was left alone until 1950, when Dr. Nell Causey revisited it, noting the illustration of the gonopod differed from Bollman's description. She deemed it distinctive enough to be its own species, which she named Chaetaspis ohionis. It's unclear whether or not she was able to examine the type specimen, which was listed by Chamberlin & Hoffman (1958) as being in the Miami University arthropod collection. Somewhere along the line, however, the type specimen was lost (Lewis & Slay 2013). That means now no one can look at the specimen Williams and Hefner were looking at to see what it actually was: all we have is figure 12 and their description.

So...that leaves us at a brick wall. Hoffman (1999) wrote that the millipede isn't even a species of Chaetaspis, and is probably part of a different family, in his opinion. But if it's not a Chaetaspis sp., then what is it? Williams and Hefner were convinced that it matched Bollman's description of Chaetaspis albus, except for its larger size.

This might seem like a waste of time, since we have no type specimen. But it's an intriguing mystery to me, since I'm from Washington County. It would be super neat to mount an expedition and find the millipede that Williams and Hefner did (albeit a difficult one, since they didn't specify the locality), and it could corroborate (or not) Chaetaspis ohionis being a new species.

Think of it as CSI: Millipedes.

References:

Bollman, Charles H. 1893. The Myriapoda of North America (A posthumous edition of Bollman's works by L. M. Underwood). Bulletin 46, U.S. National Museum. 210 pp.
Causey NB. 1950. On Four New Polydesmoid Millipeds. Ent. News, vol. 61, No. 7, p. 197
Chamberlin RV and Hoffman RL. 1958. Checklist of the Millipeds of North America. United States National Museum Bulletin 212. 236pp.
Hoffman, R.L. 1999. Checklist of the millipedes of North and Middle America.Virginia Museum of Natural History Special Publication. v. 8 p. 1–584 Lewis JJ and Slay ME. 2013. Chaetaspis attenuatus, a new species of cavernicolous milliped from Arkansas (Diplopoda: Polydesmida: Macrosternodesmidae). Journal of Cave and Karst Studies, v. 75(1): p. 60-63.

Invasive Insects in Ohio: The Hemlock Wooly Adelgid

Globalization strikes again! The main invasive pests I've been hearing about in Ohio over the past few years have been the Emerald Ash Borer (Agrilus planipennis) and Asian Longhorn Beetle (Anoplophora glabripennis), but I now have a new one to add to my list: the Hemlock Wooly Adelgid (Adelges tsugae). The Hemlock Wooly Adelgid (HWA) is a true bug in the order Hemiptera and is sort of like an aphid. Adelgids suck plant juices out of conifers, and HWA prefers hemlock trees, specially the eastern and Carolina hemlocks (Tsuga canadensis and Tsuga caroliniana, respectively). This is a problem.

HWA was introduced into the US from Asia in the 1920s, first in the Pacific Northwest, and then in Virginia in the 1950s. That was the start of its foothold in the east, and it spread to other states from there, including Pennsylvania and West Virginia. It didn't reach Ohio until 2001, and has spread into about 27 counties since then.

Unfortunately, in 2012 it was detected in my home county, Washington County. It was found in Belpre and Marietta, probably due to natural spread from nearby areas--possibly from across the Ohio River: Wood County, West Virginia has reported HWA. The Ohio Department of Natural Resources held an informational meeting about the HWA yesterday in Marietta to talk about its biology, risk to hemlock trees, and what the state is doing to stop its spread, so I attended and took some notes. The next few paragraphs are a quick summary of the meeting.

Eastern Ohio is where most of our hemlocks (T. canadensis) grow. Eastern hemlock prefers rocky sandstone gorge type habitats and is very shade-tolerant (so think Hocking Hills region). It can often develop into pure stands where it grows, but is also planted as an edge tree in more urbanized areas. It can act as a foundation species for an ecosystem, supporting many bird species (nearly 100 have been identified as being associated with eastern  hemlock in some way) and it can also strongly regulate aquatic ecosystems by shading streams.

Ohio's forests don't have many conifers. Most of the forests consist of deciduous trees, but eastern hemlock is one of our common conifers, which means HWA poses a real threat to taking out a good-sized chunk of Ohio's conifer trees. HWA can cause tree mortality in 4-10 years, less if the tree is stressed by factors such as drought. HWA feeds on the tree's leaves and can be detected on a tree by the white, waxy residue that covers its body (hence the "wooly" adjective in its name). Essentially, it will look like cotton candy or spider webs on the tree.

HWA has a complex life cycle, and only the first instar (life development stage) is very mobile. There are two generations per year, and the winter generation can produce egg sacs with up to 300 eggs. The complex life cycle makes it difficult to control by introducing predators, but there has been some success on that front and beetle introduction is seen as a long-term solution. Another control option is the use of insecticides.

When it comes down to it, the state agencies involved in invasive species management need the help of the public to do their job. Tackling the HWA is no different. This includes keeping an eye on the trees and reporting the movement of wood products in counties with quarantines. Otherwise, HWA can spread under the radar. Whenever it's reported from a county, it's usually because someone noticed something strange on their trees and called it in. For example, an infested site in Marietta was found because a college student fell out of a tree and brought down some infested branches with him.

There's not nearly enough funding devoted to detection and eradication of invasive species, so we have to do the best we can with the resources we have. For more information on the Hemlock Wooly Adelgid, check out the links below. And if you notice something on any hemlock trees that looks out of the ordinary, report it!

Ohio Division of Forestry Fact Page
Ohio Department of Agriculture Fact Page

What's out there? Compiling a biotic index.

Do you know the insect species that inhabit your backyard? What about a local park or nature preserve? How about your county? These are important questions to think about. If no one knows the animal diversity in their area, then why would they stop to think about protecting that diversity?  Some of the most interesting animals are very specialized and need certain habitats to thrive; without those habitats, they'll disappear. I think we can all agree that nature is important, and having a knowledge of your local species (of insects, mammals, birds, plants, fungi...) is empowering. You can see ecological connections and gain a new-found respect for your fellow organisms, just from being able to identify species and know what's around you.

 A Luna Moth (Actias luna) soon after emerging from the ground. Its wings aren't yet ready to fly--you can see how small they are.

With this topic in mind, I've been working for the past few months on gathering together pictures and information about arthropod species that occur at the Barbara A. Beiser Field Station (BBFS) near Marietta, Ohio. As I've written about before (here and here and in an article for the Marietta Natural History Society newsletter here [PDF]), I conducted a lot of my undergraduate research at the BBFS and found many species. I never quite had the time to identify and write down all the species I found while I was an undergraduate, so I put it off for a while.

Until now.

An Ichneumon wasp, Megarhyssa macrurus, drilling into a dead tree to parasitize a wasp larva.

After months of identification, I've completed the project! (I'm looking for a good way to put this list online.) This is the first biotic index (list) of species from the BBFS, and focuses only on arthropods (it will be expanded to plants and other groups in the future). All in all, I identified 181 species including insects, arachnids, and millipedes/centipedes. This is nowhere near a complete list, but it's a start. I only included arthropods whose identifications I was sure about, so I left out a few species I was unsure of, falling just short of my 200 species goal. But that's okay--the list isn't useful unless it's accurate, after all!

A pair of Euryurus leachii millipedes under UV light. Usually found in decaying logs, these millipedes fluoresce a pretty bluish-green color.

I gained a lot of experience with local insects while working on this project and feel pretty confident about being able to identify many of the insects in Washington County. I now have a much greater knowledge base about insect taxonomy and what a "species" really means. When it comes down to it, a species is someone's hypothesis, and sometimes the hypothesis isn't accepted by everyone. It can be based on tiny characteristics that are a real pain to hash out, especially when you're trying to identify an insect in a group that's not well-studied!

What did I learn after putting together this list? Most importantly, I learned that I still enjoy taxonomy after hours and hours of (sometimes frustrating) work. I also learned that we have some astounding arthropods at the BBFS, and in the county. Throughout this post I've included pictures of arthropods I found there that I never knew about before, with life histories that are seriously interesting and unfortunately too long to include in this post. There's a diversity of life in southeast Ohio I never would have known about before undertaking the research I've done and I'm lucky to have had that opportunity. It's taught me that you don't have to go to the rainforest to find beautiful and interesting animals; sometimes the forests of southeast Ohio can beat out the rainforest!

A male Marbled Orbweaver, Araneus marmoreus. This spider has many color forms, of which the black and yellow form is especially striking.

I hope to use my experience to encourage others to take a second look at the critters in the area and to truly take pride in them. Why not say "These things are astounding!" and put these animals on a pedestal? Arthropods like the Luna Moth, the Ichneumon Wasp, our UV-fluorescent millipedes, the Locust Borers, the Wheel Bugs: these "bugs" are crazy awesome and should be celebrated!

The Spicebush Swallowtail caterpillar, Papilio troilus. This unique caterpillar changes throughout its life stages--young caterpillars look like bird poop, while older ones (like this one) mimic snakes!

In order to accomplish this goal, I'm working on completing another biotic index--this time for Washington County, with some input from surrounding counties. I want to adapt this larger biotic index into a field guide to arthropods in the area, with pictures and information about each species. It will introduce people to these bugs and save them some time in trying to identify them. Essentially, I want everyone to have the same pride in our many-legged fauna as I do.

Narceus americanus, the gentle giant. This is the largest millipede in our area and eats dead leaves. Interestingly, it sometimes scales trees.

It doesn't help anyone appreciate our arthropods if I keep my knowledge locked up in my head, so I need to spread it! I have no idea about how long this project will take, nor when it will be done, but it hopefully won't take more than a few years max. If you can help out in any way, please contact me!

Dancing Stick

The species I find in the county never cease to amaze me.  This delightful stick insect, for example, takes a discerning eye to pick out in the forest.

"My dream in life is....TO DANCE!"

But not really. This guy found me when he started to crawl on a friend during a recent potluck. It's a Northern Walkingstick, Diapheromera femorata, the continent's most common walkingstick. It's about three inches long, but looks bigger because of how long its legs are. 

Its limbs are leafy green and its body looks like it's been sculpted straight from a tree, giving it some terrific camouflage. I've been observing it in an insect cage for the last few days and it truly is a remarkable insect. Walkingsticks are the world's best method actors, taking their role as a stick very seriously. 

...which is a good strategy, as birds are liable to pick these guys right off the plants they're feeding on. 

Mission Complete: Skunk Cabbage

A year ago, while I was in Costa Rica studying abroad, I heard about the mythical skunk cabbage, Symplocarpus foetidus. This magical plant was said to flower during late winter and early spring, and to even have the powers to melt snow around it and attract some of the first insect pollinators of the year.

After seeing some marvelous pictures of this legendary arum, I resolved to find this plant myself. Unfortunately, I was in Costa Rica. (Yes, I'm aware that this is probably the first time that sentence has ever been said.) By the time I returned to the United States, the flowers were gone.

But now, after an entire year, we're in the correct season and all the elements have come together to form perfect skunk cabbage weather. Today, my class schedule even worked out, resulting in my Lower Plants lab taking a trip to search for the prize.

Ladies and gentlemen: we have skunk cabbage!

As we entered an area with a natural seep to look for the cabbage, we were teased with the...."distinct" smell of skunk cabbage. It was either that, or sewage. At any rate, I was mad with a feverish yearning to find this most desirable of cabbages. Descending a hill, we entered a wet area and knew we were close. My eyes scanned past a growth of cattails to discover standing water.

My mind was racing.

I searched for any characteristic feature: mottled red on green, bright green leaves...anything not familiar to me. And th--HOLY CRAP, THERE IT IS!

Like a beautiful green sentry, there the skunk cabbage leaf stood: curled up, surveying its territory from CENTIMETERS above the water. Truly, this is royalty. I jumped up and down and shouted for joy, much to the chagrin of my lab companions. However, manners were secondary to my cause at this point. After about five minutes of bolting from plant to plant, I finally settled down enough to examine the Hope Diamond of plants.

Being in the arum family, skunk cabbage has a spathe and spadix. The spathe is actually the fleshy, modified leaves surrounding that weird-looking ball in the middle of the plant. That pimply ball is the spadix, which has small, white flowers that are pollinated by insects such as flies, bugs, and beetles. Since the flowers are so inconspicuous, they aren't in charge of attracting the pollinators. Rather, that delectable stench is the attractant. It worked pretty well on me, so it must be good enough for all those pollinators, eh?

I was positively giddy once we found the skunk cabbage--probably to the point of freaking everyone else out. My long year of waiting was well worth it: I was not disappointed at all with what I found. This is truly a remarkable plant...from the smell to the colors to the message. If you find skunk cabbage, it means Spring surely isn't far away.

Get out and look for skunk cabbage while you can still see the flowers: you won't be disappointed. Snow won't even kill it at this point, thanks to its thermogenic qualities (it's somewhat of a dragon really), so you have no excuses not to get skunked.

Seriously, go. It's so amazing!