Walking sticks

When I was a kid, I was obsessed with finding one of these:

Photo by C. Sohl

I never could find one in the wild, partly because they're so good at camouflaging with their surroundings. The above walking stick is from our own teaching collection. This particular specimen is about 4 inches long, but walking sticks can grow to a foot long or more! Walking sticks are in the order Phasmatodea, and as you can see, they are masters at disguise. Some resemble brown twigs, while others look more like leaves.

http://en.wikipedia.org/wiki/File:Phyllium_bilobatum,_male_larva.jpg

Some will even rock back and forth in a swaying motion, as plants will do in a breeze.  Below is a you-tube video of a walking stick in motion. You can see the rocking motion here, too.

Walking sticks have compound eyes, which is the same type of eye on a fly. Interestingly, the eyesight of a walking stick improves with age, each time that the insect molts. They can also see particularly well at night, which is when they are most active. In fact, daylight can actually harm their sensitive eyes. I imagine this did not help in my quest for finding one of these creatures.

Another aspect that is unusual about these insects is their mating behavior. Walking sticks have a tendency to stick together - mating can go on for days at a time. It's thought that this is due to defense mechanisms - if the male stays close, he can protect the female from any other males that may try to mate with her. This way, he can be sure that she'll lay his eggs. In addition, dealing with two of these insects can be more challenging for anything that might try to eat them. Many female walking sticks have the ability to lay eggs without the need for a male - perhaps this is a reason why the males do not want to let go of the females so easily! 

Below is a coupling of male and female walking sticks. The male is actually the smaller of the two, and apparently clinging to her for dear life. 

http://en.wikipedia.org/wiki/File:Anisomorpha-male-female.jpg

You can keep your eyes open for these, but you may not be able to find these quite so easily as other insects. I haven't given up just yet myself.

Happy Friday!

Leeches!

    Recently a friend of mine posted a video on the social networking site Facebook of a scene involving leeches and the TV show Fear Factor. Leeches, as you all can guess by me taking about them in this blog, are invertebrates that almost exclusively feed on blood of other organisms. They are slippery, they are slimy, and for most people the first thing that comes out of their mouths when they think or see leeches is "Gross!". In fact, I'm one of those people too...even though I respect them, they are on my "yuck" list, mostly because they feed on blood which bothers me more than the leeches themselves! Fear factor loves to use invertebrates in their show, from roaches to scorpions to worms because most people have an "ick" factor to any invertebrate, so having leeches was a new addition to their arsenal.
    In the show's episode the woman of the couple has to sit in this tub filled with leeches for 30 seconds, let them attach to feed, and then get out so her partner can then bite them off of her. He then has to eat 30 of them, and then she has to eat another 30. Talk about not the most appetizing meal one can have, and for most people it would be scary. The link to the video is here on Hulu. Most people's reaction after watching the video is why on earth would we have such things, and are leeches really good for anything other than sucking blood of reality show contestants?

Image of a medicinal leech, Hirudo medicinalis, from Wikipedia.com

    The answer is yes leeches have been around for a long time and have their place in the ecosystem, but what most people forget is that leeches actually were a pretty "normal" thing for people to see in Western culture because they had a big part in our medical history. Medicinal leeches, which were likely the leeches used in the TV show, were used to "bleed" patients that were sick and was thought to help remove the toxins affecting their health. In fact, the large amount of leeches they got for the show is likely because they were being bred for modern-day medicinal uses, and were probably fairly hygienic to eat as far as leeches go (the worst thing that can probably happen is the bites from leeches get infected later on, but for the most part the bites are fairly harmless). Wikipedia has a nice article about the use of leeches in the past for medicine here, and there is a long and neat history about how using them came about.
    Even though we don't do bleeding in medicine anymore, the use of leeches in modern surgery is bringing leeches back into the medical limelight. Leeches have an anti-coagulant (blood thinner) and feed without really being noticed (they anesthetize the site so you don't feel the pain), which makes them good candidates for increasing blood flow to delicate structures that are being attached or re-attached, or wounds that have difficulty healing. For example, here is a link to an interview with a doctor at the University of Mississippi Medical Center who talks about using leeches for wounds.
    So, yes the video of the a tub of leeches seemed nasty and would lead one to wonder why we want such creatures around us. However, these little guys do have a place in our world and even have useful applications to modern society, especially outside of fodder for reality tv!

Crazy Crayfish

    This June and July we've been fortunate to have a graduate student assistant work in our Recent Invertebrates Collection. Eric Bright, who is getting his PhD in freshwater ecology, is cataloging and rehousing our crayfish collection. This is really important for us, since we have lots of historical crayfish specimens from rivers and lakes that have had drastic changes over the years in Oklahoma (being damned up, agricultural run off, etc) and therefore its an important collection.

Eric holding up one of the recurated crayfish specimens he worked on

    The first problem that we had twas that many of the jars that the crayfish were stored in were never meant to hold alcohol for long periods of time. There were a few specimens in old peanut-butter and pickle jars, a few in tall jars with wire locks and rubber gaskets that solidified into solid blocks of plasticy goo, and other nasty conditions. This put the specimens at risk since if alcohol was leaking out (which was often the case), they would dry out and not be usable. Further, some were nearly impossible to open because of the rust or rubber sealing the tops, so we couldn't actually look at the specimens. Eric had to break the tops off with pliers and a rubber mallet just to get some of the tops off! The old glass that was recyclable was put in the bucket to be taken to the Norman recycling center, and the crayfish were put into new jars with archival plastic lids that will ensure the alcohol doesn't dry out and they can be opened again.

Some of the old jars that are now ready to be recycled. You can see some of the old, dissolved rubber gasket still stuck on the rims of some of them.

     The second task Eric took on was to catalog what was in each jar, and the information of where, when and how the crayfish were collected. Many of the specimens were collected by the Fish department when they did aquatic surveys in the 1980s and 90s of different bodies of water, but we also have some crayfish from the 1920s and 1930s that were collected when the University of Oklahoma did in massive sampling surveys of the state. Again, these specimens from that era are especially important because a lot of the water ways have changed since then (especially after the Dust Bowl), and we can use them as comparison points. Overall, though, there seems to be a trend in the numbers of species of crayfish going down as our water use and landscape has changed. A neat website about Oklahoma crayfish and their current status can be found here at these links:
http://iz.carnegiemnh.org/crayfish/country_pages/state_pages/oklahoma.htm.
http://www.wildlifedepartment.com/wildlifemgmt/species/crayfish.htm.
    So far Eric has gone through hundreds of jars and thousands of specimens, making sure the information we have for them is kept in a digital file for our database and that they can last at least another 80 years in new jar homes. We are very grateful, as should be hopefully many future generations of Oklahomans that hope to study these neat little guys too.

Yay for crayfish!

Lightning bugs!

The first time I saw one of these was when I was waiting for 4th of July fireworks when I was 12 years old. I thought they were some of the coolest bugs ever.  Apparently my grandmother did as well, but for other reasons - when she was little, she mashed them up on her hands and pretended she was wearing sparkling diamond rings. Now, I can't say I did that myself, but I DID very much wonder what made these insects glow the way that they do.

First of all, what is this insect? It's actually a member of the order Coleoptera, so it is actually a type of beetle. In the daytime, they look like this:

http://en.wikipedia.org/wiki/File:Photuris_lucicrescens.jpg

But you're probably more familiar with the cool green glow that you see blinking on and off at night.

http://en.wikipedia.org/wiki/File:Firefly_composite.jpg

So what is that, exactly? Bioluminescence, that's what! You may have heard of this before - there are quite a few members of marine life that have this chemical reaction as well. Some squids, crustaceans, fungi, and fishes are bioluminescent - usually those in the deep waters that don't have much access to sunlight.

http://en.wikipedia.org/wiki/File:PanellusStipticusAug12_2009.jpg

Bioluminescent dinoflagellates are also responsible for the green glow that oceans occasionally appear to have. Bioluminescence is a chemical reaction involving an enzyme called luciferase, according to my handy Borror and Delong's Study of Insects (2005) Entomology text. When the insect breathes in air, it is oxidized, and then the energy is released as light. This light can be seen in the abdomen of a lightning bug.

Most likely, the point of this glow for lightning bugs is to attract mates, although sometimes it is used in a predatory fashion to attract meals. Females also tend to have a brighter glow than males.

Keep your eyes open and maybe you'll see these neat little beetles while you're waiting for your fireworks show. Happy 4th, everyone!