Monday, 30 January 2012

Insects Galore: A guest blog for Explore the Outdoors


This post was written as a guest blog for Explore the Outdoors, a program started by the Ohio Department of Natural Resources that endeavors to educate people about the natural wonders of Ohio. I highly recommend that you check out their website--it has great information on outdoor activities and state parks and reserves you can visit in Ohio. You can see my original post here.

Winter can be a beautiful time of year (when the weather deigns to give us snow), but if you're like me, it can also be pretty dreary for one important reason: there aren't many insects about. Sure, you might get lucky and find some stink bugs crawling around inside your house or come across a camel cricket or spider (not actually an insect, but an arachnid, of course) in your basement, but the assorted stragglers can't quite satiate the need to see our many-legged friends like the other seasons can.

If you haven't noticed yet, this post is going to emphasize how amazing the insects and other terrestrial arthropods are. First, let's establish some background. If you aren't already a fan of insects and would rather step on them than appreciate them, ponder this: out of all living organisms on the planet, over half are insects. Furthermore, out of all the animals, almost 75% are insects. When you include the other arthropods, it increases to 86%. Keep in mind that these are only species we have described so far: estimates predict that over 90% of all animals are insects. The sheer amount of diversity among the insects shows us that this is one important group. Keeping that in mind, let's explore the diversity of insects in Ohio.

Nature, and in turn, insects, are not things you have to drive to the outskirts of civilization to experience. It is (obviously) literally all around us, and this is especially true with regards to the insects. When I first learned of the total insect diversity, I was a bit skeptical. After all, I hadn't really noticed too much variability in the insects, other than mosquitoes could suck my blood, bees could sting me, and scarab beetles had a penchant for flying into porch lights during the summer. It wasn't until a few summers ago that I truly started looking for insects and observing the mind-blowing amount of variability there actually was. I started a personal project documenting the terrestrial arthropod diversity in my own backyard (I didn't want to make the spiders and millipedes feel left out) and have kept at it for three summers. I went through my yard a few times a week, taking an hour-long walk examining the trees, shrubs, and other vegetation during the day and night, just taking pictures and finding what I could. My current tally surprised me: to date, I have found over 100 different species.

The kicker? All of these insects, spiders, and millipedes have been found in an area only one acre in size. Now that's impressive! The phrase "backyard biology" has never been more relevant! But that's enough talk, it's time to look at some of the beautiful and interesting insects that Ohio has to offer.

First up is an ant.


  Well, not exactly. If we take a closer look, we learn...


 ...that it's not an ant at all! This is actually a jumping spider in the family Salticidae that mimics an ant, Synemosyna formica. I start off with this spider to illustrate two points. Firstly, that Ohio has some interesting and surprising diversity. Secondly, that it is important to pay attention. You'll find that these little critters can be surprisingly crafty, in a variety of ways. For example, a spider only has two body segments: the cephalothorax (head) and abdomen. In this species, its body is constricted to make it appear to have three body segments like an ant. In addition, it holds its front legs in front of its body, mimicking the antennae of an ant. You can see how small the spider is from the first picture: at most, these spiders will grow to just under six millimeters long. When I found this spider in my backyard, I thought it was an ant. That is, until it declined to run away like the other ants in the area. Instead, it stayed on the underside of the leaf I found it on, unmoving. This isn't ant-like behavior, so I caught it on the hunch that it might be something different.

Next up is an insect that a friend described as looking like "a Balrog that got hit with a sneeze of tie-dye." It may look ferocious, but it's actually harmless to humans. Other insects....well, not so much.


This is likely the biggest wasp you're going to find in Ohio: the giant ichneumon wasp, Megarhyssa macrurus. In this photo, it's inserting its three inch long ovipositor into the dead wood of a tree, in search of one thing: the larva of another wasp, the pigeon tremex horntail (Tremex columba). It can detect the wasp larva's movements in the wood, locate it, and then lay an egg next to the larva. Once the ichneumon wasp has done this, it will then sting the horntail larva, paralyzing it. Later, the ichneumon wasp larva will hatch and devour the horntail wasp, and continue to grow to adulthood.

With a lifestyle like that, it's a good thing this wasp is harmless to humans! It's difficult to convey in a picture just how beautiful this wasp truly is: the mixture of amber and yellow blend together to create one of the most jaw-dropping insects around. If you're walking in the woods and come upon some dead trees in a sunny area, search around a bit and you might be lucky enough to find one.

This next insect is a personal favorite of mine. It's a member of a fascinating family of bugs called the assassin bugs, a predaceous family that preys upon other insects. They are generally considered beneficial insects and are currently being studied for use in biological control regimes. Something called an assassin bug probably isn't going to be too peaceful, obviously, and these insects earn their name. They're ambush predators, and once some prey comes into their hunting ground, they creep up behind the prey and strike. They have a mouth like a straw, which they plunge into the unsuspecting victim, pumping it full of digestive fluids to paralyze and liquefy the insides of the unfortunate insect before sucking it out. Not exactly the most polite thing to do, but it's a way to make a living.


In Ohio, we're lucky enough to have the largest terrestrial true bug on the entire continent in our backyards: the wheel bug, Arilus cristatus. The picture above shows its namesake: a structure on the top of the thorax that looks like a cogwheel. This particular wheel bug has just emerged from its final instar (the fancy word for a juvenile stage in the life of an insect), hence the pretty salmon color. After a few hours, the color fades into a grayish black that camouflages the wheel bug against trees. The wheel bug can grow a little larger than two inches, making it a formidable predator. Its size allows it to take on large prey and equips it with the weapon to do so: its beak is longer than its head. This can be intimidating to humans, and the gut reaction of many people is to either run from it or squash it. This fear is not well-founded. While the wheel bug can indeed inflict a painful bite (being bitten by an assassin bug isn't even an entomologist's idea of fun), it will only bite when provoked. Even then, it might not bite. I've handled many wheel bugs and have yet to be bitten: the key is to respect it and handle it with caution. I wouldn't recommend handling a wheel bug, but it makes an interesting insect to keep in an enclosure (it's in a butterfly cage in the picture) and observe its habits. It's best to only do this temporarily and then release it to go on about its business, but it's a valuable learning experience.

No mention of Ohio's insect diversity would be complete without what many would argue to be the most beautiful moth in our area, the Luna Moth (Actias luna). I had a massive stroke of luck in my adventures this summer, with regards to this moth. I was researching assassin bug diversity at Marietta College's Barbara A. Beiser Field Station in early summer when I heard a strange sound coming from some grass. I bent down and searched for the source of the noise when something came crashing through the undergrowth.


A newly-emerged Luna moth was crawling towards me. There was no question that it had just emerged: its wings weren't yet pumped up, so it was in search of a tree to crawl up where it could safely expand its wings. Seizing the opportunity (as well as the moth), I placed it on a nearby maple tree and observed it for the next three hours. It takes a while for the moth to complete this task, and moths are at their most vulnerable at this stage: they can't fly away, and are nice protein-rich meals for any other animals that might happen upon them.


You can tell that this individual is a male, due to the thick antennae, which he uses to detect pheromones from the female: chemicals that let the male know where the female is located and if she is ready to mate. Adult Luna moths don't feed, focusing solely on mating to usher in the next generation. In fact, adults don't even have functioning mouthparts. Due to this, they only live for about a week, so mating is the top priority in such a short time.

The Luna moth is in the moth family Saturniidae, a group that includes the biggest moths in the world. The Luna moth is no exception, with a wing span reaching up to 4.5 inches. The wing span of the Cecropia moth, North America's largest native moth, is over 6 inches. Once you've seen these moths, you're not likely to forget them. They're attracted to lights, and are more abundant near forests, so start your searches there!

This is just a small sample of Ohio's insects: some are even more colorful and have novel life histories. I haven't even mentioned the beetles, which are the most diverse group of insects. In fact, one out of every four living things on Earth is a beetle. Isn't that marvelous?

In a few months, winter will be over and the insects will once again grace us with their presence. I encourage you to go outside and look around your own backyard to see what you can find. If you want to go further and identify what you've found, BugGuide is the best resource for North American insects on the web. If you want to go further than that, Nature 2.0 websites like Project Noah allow you to upload photographs of the organisms you find, and are great for keeping a record of what you've found.

What should you do if you want to find insects now? Well, the winter stoneflies should be coming out pretty soon...

Friday, 27 January 2012

Science Video Friday - Vampire Moths!

You may have read in a textbook that moths and butterflies feed on nectar from flowers, or don't even feed at all. When reading about science, however, it's important to remember that things aren't simple. It's difficult to neatly fit everything into one classification, and this holds true with the Lepidoptera as well.

In this instance, it means that we should say most moths and butterflies feed on nectar. Some feed on fruit, for example. One moth in particular does something much different. It's related to a species that feeds on fruit, but gets its food from another source. No, it doesn't feed on vegetables, but instead...blood.

Wait, what?

National Geographic has you covered for this week's Science Video Friday!


Wednesday, 18 January 2012

Marine Debris: One Huge Problem

Do you ever stop to think about where the trash you throw out each day ends up? A landfill, you might say. Or, if you live near the coast, you might consider the chance that your trash could end up in the ocean. That's a pretty good guess. Literally tons of garbage enter the oceans and rivers each year, including plastics.

To illustrate this problem, Woods Hole Sea Grant created a poster detailing how long trash remains in the environment, and where the trash is coming from.


This is one reason why recycling is so important: it keeps trash like this out of the environment. Once trash items enter the environment, it can take a while until they go away. While time works its toll on these items, they don't stay in one place. In the ocean, this results in the trash being moved around by ocean currents. 


In the Pacific Ocean, this has created what is known as the "Great Pacific Garbage Patch." In the above picture, the area marked "Convergence Zone" is where much debris accumulates. You can't actually see much of the patch with the naked eye, as it's composed of bits of trash (mainly plastic), and there are separate "patches" of garbage within the convergence zone. A good description of what you can see at the garbage patches can be found here

But not being able to see the plastic does not mean that it isn't causing problems. These tiny bits of plastic enter the found chain, due to being ingested by marine organisms such as fish. The chemical composition of the trash that animals eat can mess with the animals' organ systems: affecting their quality of life and even reproduction rate. 


As illustrated in the above photos, the bits of plastic that fish eat can be quite significant, leading to problems. A pressing problem for the fish is a nutritional deficient: if its stomach is full of plastic, it feels full, so it doesn't continue feeding, but it hasn't actually gained the correct amount of nutrients it needs.

Even though the garbage and plastic that makes its way into the ocean is invisible to us, it obviously has an effect on marine organisms.

To wrap this up, the following 4 minute video illustrates the harsh life of the organism that is perhaps most affected by this pollution: the plastic bag.


References:
Gregory M. (2009). Environmental implications of plastic debris in marine settings– entanglement, ingestion, smothering, hangers-on, hitch-hiking and alien invasions. Phil. Trans. R. Soc. B. 364(1526): 2013-2025.
Muncke J. (2009). Environmental Hormones in Food Packaging: Migration into Food and the Environment. PDF.
Pichel, W., J. Churnside, T. Veenstra, D. Foley, K. Friedman, R. Brainard, J. Nicoll, Q. Zheng, and P. Clemente-Colon. (2007). Marine debris collects within the North Pacific Subtropical Convergence Zone. Marine Pollution Bulletin 54: 1207-1211.
Rios L.M., Jones P.R., Moore C., Narayan U.V. (2010). Quantitation of persistent organic pollutants adsorbed on plastic debris from the Northern Pacific Gyre’s “eastern garbage patch.” Journal of Environmental Monitoring. 12(12): 2189-2312. PDF.

Further Reading:

Friday, 13 January 2012

The Amber Flame Tree

It has now been a year since my journey to Costa Rica as part of a semester study abroad experience focusing on Biology and Spanish. I returned last May, and one of the things I was most looking forward to was fall: I needed to see some explosive leaf colors. Don't get me wrong, the plants I saw in Costa Rica were beautiful and vibrant green, but it's difficult to compare that with the leaf colors you can see during an Ohio autumn.

As fall came and went, I saw some wonderful colors, and gradually came to the realization that one of my favorite trees is the American sweet gum, Liquidambar styraciflua. Even its scientific name is beautiful and rolls right off your tongue, it's fantastic.

The leaves of the tree are palmate to be technical, but I would rather describe them as five-pointed stars.


The colors of these leaves are astounding and range from green to purple, with yellows, reds, and oranges in between.The maples have nothing on this tree!

Leaves of a young tree.



Notice the variability in leaf color and shape.

Not limited to just the leaves, the fruit of the tree is interesting as well. It's a spiky capsule that every kid on the playground in my elementary school days knew about: we called them monkey balls and threw them at each other.

Sometimes they could hurt. Then we would get in trouble.

The dried fruit. If you look closely, you can see a spider web.

The fruit is composed of many capsules (according to Wikipedia, 40-60), which contain the seeds. Many of the seeds from the fruit end up being aborted, and fall out of the fruit as chaff. The seeds that develop fully and are released, however, are small and look like small wings. I have a few fruits in the lab, I'll get a picture and update this entry later with pictures of the seeds and chaff. 

I recently learned that the young bark of the sweet gum has a warty appearance, something I had never seen before: until I was shown a young tree at the Kroger Wetlands during a flowering plants class.


The sweet gum is easy to identify during the winter (woohoo!): all you have to do is look for the tree with spiky fruits hanging off all its branches: there will be many. Some people don't like the tree because of all the fruits it produces, which can make a lawn lumpy and not much fun to walk across, but that's a small price to pay for a tree as beautiful as this. 

Sadly, I've yet to nab a picture of the flowers, but that gives me a goal for the coming spring!

Further Reading:

Friday, 6 January 2012

Science Video Friday - Macoto Murayama's "Inorganic Flora"

This week's Science Video Friday features some interesting art. It's a visualization of the orchid Cattleya warneri, shown in a way you haven't seen before. To learn more, check out the article on Tree Hugger.


Wednesday, 4 January 2012

The Luna Moth: A Photo Essay

One of my goals for this past summer was to find as many moths in the family Saturniidae as I could. The saturniids are the moths that give moths great publicity: they're huge, they're colorful, and they make their presence known. In fact, this family includes North America's largest native moth: the Cecropia moth.

The Cecropia moth: Hyalophora cecropia. With a wingspan of up to 6 inches, it is a HUGE moth.

I was out at the Barbara A. Beiser Field Station often during the summer, and on my first day there, in late May, I struck gold. As I knelt down to examine a Clubtail dragonfly (Gomphus sp.), I heard a strange rustling in the grass nearby. I took a few quick snapshots of the dragonfly and turned around to see what was causing the ruckus. I could hear it, but due to the dense, wet, matted grass, I couldn't quite find it. 

And then I saw it.

But...what was it, exactly? My eyes darted around, surveying the yellow, white, and maroon mass crawling towards me. At first, it looked like two beetles wrestling and falling through the undergrowth. Confused, I took a closer look and realized what was actually coming at me.

Trust me, that totally looked like two beetles when I first saw it.

Full of glee, I realized that I was looking at a Luna Moth (Actias luna), one of the saturniids I was searching for! However, it did not look like what the Lunesta commercials had led me to believe what a Luna moth looks like. First of all, it did not glow. Secondly, its wings were shrunken, and the abdomen looked distended.

Not yet ready for flight.

There could be only one explanation: this individual had just emerged from its pupa! That's even more exciting than finding an adult flying around! I knew then what I had to do.

 Need a hand?

To avoid accidentally stepping on it, I picked it up and placed it on a nearby maple tree.

 
That's not quite what you're used to seeing from a moth, huh? The abdomen was bulging with that green stuff, which I assume is hemolymph that it was planning to use to pump up its wings.

Notice the antennae and how plumose they are: that indicates a male. The males need huge antennae to pick up the pheromones of the females, a surefire way to find a mate!

After placing it safely upon the tree, I waited. Not wanting to waste all day watching a Luna Moth pump up its wings (it's like watching paint dry, but more beautiful), I went along to find assassin bugs and other marvelous insects, returning at times to check up on my Luna Moth.


After three minutes of being on the tree, the Luna Moth has already set to work! You can see the wings are starting to flare out and enlarge, while the abdomen has contracted a great deal. It's becoming much more plump and much less thin. 


Just nine minutes later and the wings are hanging like trendy curtains. The eye spots on the forewings give it a look akin to the face of a wrinkly old man.


15 minutes later and you can definitely see the face of an old man. The eye spots have really come out now. Speaking of which, have you ever wondered what those eye spots look like under a microscope? Or, where the term "Lepidoptera" (the name of the order that includes the moths and butterflies) is derived from? Well, thanks to Wikipedia, your questions can now be answered!


This picture by Peter Znamenskiy shows what those eye spots really look like. You see, "Lepidoptera" is derived from the Ancient Greek words lepís and pterón, the words for scale and wing. Put those words together, and you get an order of insects that have scales on their wings. Those colorful structures that look like paintbrushes are the scales, and they give this moth its awe-inspiring colors.




20 minutes later, and we return to the Luna moth. The abdomen is now obscured by the wings, so we go in for a side view. Yep, that is one plump abdomen. But what's this? The hind wings look a bit wonky. You didn't forget that moths have two pairs of wings, right?


30 minutes in, and the moth seems to be imitating a butterfly: its wings are held above the body vertically, rather than horizontally. What gives? Well, he still has a second pair of wings to pump up, wouldn't it be easier to do that without the first pair holding them down?


After 35 minutes, it looks like the second pair of wings have a comma at the end. They probably need to pause before they finish their sentence.



Well how about that? At 55 minutes, the hind wings bring with them some nice streamers. The Luna moth is ending its sentence with an exclamation point, for sure!


He's still working hard at 1 hour and 15 minutes. Art takes time, after all.


After 1 hour and 40 minutes, you might be asking yourself: "What's with the streamers? Is the moth going to throw a fancy party?" The answer to that question is yes and no. Here's the reason for answering no: The hind wings also have eye spots, and combining the eye spots and the tapering ends of the wings might be just enough to confuse a predator (such as a bird) into aiming for the rear quarters of the moth, rather than its head. If the bird grabs the streamers, the moth still has a chance to get away. Now, why is the answer also yes? Well, the adult Luna moth does not eat. Therefore, it only has a lifespan of about one week. Due to this, the adult Luna moth lives its adult life like it's one big party. Its sole raison d'être is mating, and it devotes itself to this debauchery at full throttle. If it doesn't pass on its genes, it has literally failed at life, hence why the males have such big and sensitive antennae. If you pick up the female's pheromones, you win the game of life.


2 hours and 10 minutes later, the moth is still preparing for his fancy party: putting up streamers, acting chill, and making sure he looks good for the ladies.


Finally, after 3 hours, he's......still not ready for that fancy party. I, however, am famished. After about 7 hours at the field station, I must head out, eat, and rest. 

I loitered around for as long as I could, but I could not stay and watch the Luna moth finish up. It was fascinating to watch it progress from stumpy little cushions to bona fide tapering wings, and I found a new appreciation for these Moon moths. This was definitely a check on my list of saturniid moths I needed to see. 

So, as I often say, if you think Ohio's diversity of insects is nothing to praise, think again!

Monday, 2 January 2012

Summer Research 2011 - A Biological Survey of the Assassin Bugs (Hemiptera: Reduviidae) at the Barbara A. Beiser Field Station - Other Insects

This past summer, as I mentioned a few times before on this blog, I had the opportunity to carry out a field survey for assassin bugs at the Barbara A. Beiser Field Station. This field station is used by the biology classes at Marietta College for lab sections, such as Zoology and Aquatic Biology.

I knew that I would have a good portion of free time during the summer, and I wanted to get a head start on my capstone project, and do some more research with insects. Out of that grew a project during which I would research the abundance, diversity, and ecology of assassin bugs (insects in the family Reduviidae). I wrote up an application for an Investigate Studies Grant for these types of student-led projects from the college, and I received one to carry it out.

It took place during six weeks in May and June, and I found a lot of different species--both assassin bugs and other insects. I focused on the assassin bugs most of the time, and presented on my findings (I'll elaborate on that in another blog post, but I found 7 different species of assassin bugs) in October. Since then, I've been focusing on all the other insects I found during the project. In order to save time and keep focused, I didn't collect every insect I found, but I did try to snap some pictures whenever I found something I hadn't seen before.

Like this, for example. A scarab beetle, the Emerald Euphoria - Euphoria fulgida.

Fast forward to this past week, and I've been focusing on identifying all the insects and other arthropods I saw. Assisting me with that has been Project Noah, an amazing website that anyone can submit their pictures of wildlife to, upload them to a map, and essentially crowdsource nature with others. (It will receive its own blog post in the future.) I just finished uploading all my pictures from my Investigative Studies Grant project, which gave me a lot of time to reflect on everything I encountered. 

It also gave me a number: 137 separate species of insects, plants, spiders, fungi, slime molds, and miscellaneous other groups of life just from those 6 weeks. 

That's not too shabby, if I do say so myself. Since it's the time of year to write reflections, I figured that now is as good a time as any to briefly highlight some of my favorite photographs and organisms I encountered. I'll limit myself to five to keep the length of this post reasonable.

This was the first insect I encountered--right on the gate leading to the field station. Unbeknownst to me at the time, I would be seeing A LOT of soldier beetles (family Cantharidae). This particular one is Podabrus tomentosus, which I didn't see many of in the interior of the forest. You know what I did see a lot of? Firefly mimics. Firefly mimics EVERYWHERE. It wasn't even until I was reviewing my photos that I even figured out that most of what I thought were fireflies were actually soldier beetles in disguise. That being said, that is some amazing mimicry. (Consider that paragraph a cliff hanger, I'll cover these mimics in another post.)

Serendipity is better than skill! I got lucky on my first day at the field station and stumbled upon (literally, I almost stepped on it!) a luna moth (Actias luna) that had just emerged from its pupal stage and was crawling along in the grass. Adult luna moths only live for a week and do not only: they only live to reproduce. I had never encountered a luna moth before, so I was excited out of my mind when I found this male (notice how large the antennae are, that's how you can tell the difference between males and females). Not wanting to step on him, I picked him up and placed him on a tree so that he could pump up his wings in peace. I returned every so often over the course of three hours to watch and it was just a beautiful sight. It's a real privilege that we have such a majestic moth in Ohio.

This is the Orange-patched Smoky Moth (Pyromorpha dimidiata), a rare case in which the common name describes the organism extremely well. At first glance you might be reminded of a net-winged beetle in the family Lycidae. It's suspected that this moth is a mimic of those beetles (check out the genus Calopteron for comparison), but may also have its own chemical defenses. Due to this, the mimicry exhibited by this moth and the net-winged beetle is characterized as Müllerian mimicry. 

Since both species are toxic and have similar aposematic (fancy word for bright warning color) patterns, the mimicry works to the advantage of both organisms: predators leave them alone since they're distasteful. This is opposed to Batesian mimicry, in which a model toxic species is imitated by other non-toxic species, which obtain the same benefits without needing to be toxic themselves. It's the insect equivalent of putting your purchase on someone else's tab. For more information about this species, you can check out Ted Macrae's entry at Beetles in the Bush.

Next up is a beautiful firefly I found crawling on a decaying log.

Or is it?

Fireflies must be awesome beetles to mimic: even the click beetles (family Elateridae) are getting in on the action! Here we have Denticollis denticornis. Sorry, no common name here, but for simplicity we can refer to it as the firefly mimic click beetle. I mistook it for a firefly when I first saw it, but upon closer inspection, the flared pronotum that fails to cover the head gives it away as a click beetle. Simply a beautiful specimen, I wish I had taken the time to get some more pictures and see where it was going. Now, which mimicry would this click beetle be exhibiting: Müllerian or Batesian? For a nice discussion about mimicry's benefit to this species, check out this link to BugGuide.

Finally, we come to one of my favorite beetles: the pleasing fungus beetle Megalodacne heros. It's in the family Erotylidae and looks as if it should be coming out around Halloween. Unfortunately, this beetle is on the wrong calendar and is restricted to the summer months.

As you can guess from the common name, the beetle feeds on fungus. In this case, I found it chewing on some bracket fungus as night was falling. It's a large beetle (two centimeters long) and its elytra are quite smooth. After I captured it and took it back to the lab, I was watching it move around under the microscope. As I watched it move its leg (it had flipped itself on its back), I was awed by how smooth its movements were.

Truthfully, this beetle showed me how beautiful insects could be, just by something as simple as their movement. It was a "Eureka!" moment for me, and has ensured that this beetle will stay at the top of my list of favorite insects. 

Too often we recoil at insects and other small arthropods because they look ugly or creep us out. Casting them down in judgement is ignorant and quite offensive to how elegantly they go about their lives, however. Not until you take the time to immerse yourself in their world (that is, what life is like for organisms that are measured in inches at most) can you truly appreciate the beauty and real magic that nature exhibits.

If you're interested in seeing more of my photographs from the Beiser Field Station, you can find my collection on my userpage at Project Noah.