Monthly Archives: December 2013

Encounter with a scorpion!

I have been lucky enough to find scorpions in my waders, in my boots, in Berlese funnels, and once had them come visit my blacklight rig in Arizona to feed on the insects, but I have not been able to find scorpions just being scorpions. Earlier this week in Bienville Parish, Louisiana, I was lucky enough to encounter a scorpion, Centruroides vittatus, while looking for beetles under logs in a dry, pine woodland on sandy soil.

23 Dec 2013 - Bienville Parish, LA

23 Dec 2013 – Bienville Parish, LA

The weather was kind of cool, and the scorpion did not move at all. I took a couple of really bad photos with my cell phone and replaced the log.

Non-insect arthropods are worthwhile and and groovy. All of the Thomas Eisner millipede work comes to mind. In this case, there were no great scientific discoveries or flashes of insight, just a simple ‘GEE WHIZ!’ and the joy of seeing a bit of wildlife doing what it does (in this case trying to overwinter undisturbed). This is in area with a large feral hog population and I wondered if the hogs are a problem for the scorpions and if that influences choice of overwintering site, but a sample size of one and limited time meant I needed to move on. I have seen scorpions kept as pets and know that they are eaten, but as mentioned above: I just replaced the log. Maybe next time.

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Dung beetle battle royale

Lately I have been locked away in our secret laboratory, identifying our dung beetles from a couple projects in the Missouri Bootheel. The specimens are moved from the boxes the have resided in the past couple of years, sorted into groups that roughly look alike, and then run

A group of dung beetles ready for keying under the microscope.

A group of dung beetles ready for keying under the microscope.

through a dichotomous key to confirm they are alike or separated. When most people think of dung beetles, they think of scarabs. If you pay attention to the dung you will find that many of the beetles you find will not be scarabs, but will be adapted for a dung lifestyle.

In a previous blog post I talked about the need for the correct key, and because many of the non-scarab dung beetles look like scarabs you will be tempted to run them through scarab keys. A close look at the antennae should keep you safe from falling into a morass of KEY FAILURE, where nothing works. Among the non-scarab dung beetles are Hydrophilids, or water scavenger beetles. These ‘dung beetles’ have a major distinction that makes them different from the scarab dung beetles – they are predatory as larvae (but this feature never shows up in any key – thank goodness). I know you have always thought of a piece of poo as tranquil, nice place to raise up a brood of kids, and I hate to ruin this idyllic notion, but predators run rampant in this environment. The hydrophilids in poo are beneficial because they help control fly populations, which came be a problem in livestock production.

Cercyon quisquilius, a tiny, but voracious, predator in the poo

Cercyon quisquilius, a tiny, but voracious, predator in the poo

A favorite poo hydrophilid is Cercyon quisquilius. Carl Linnaeus, a botanist, (and the first modern taxonomist) initially named this species Scarabeus quisquilius putting it firmly in the family Scarabaeidae, because the family Hydrophilidae didn’t yet exist. As our understanding of these beetles grew, so did our taxonomy. As I work with these beetles, my understanding of their roles, my appreciation of their innate grooviness, and realization that a poo is not a nice place to live increases.

There is no substitute for using the correct key

Dichotomous keys are wonderful things. In addition to increasing your vocabulary with words like piceousfistulous, and about 7,000 different words for plant hairs (e.g. dolabriform); dichotomous keys can give one the ability to identify any species with certainty… almost. Some keys are written with characters that don’t provide much separation (e.g. structure length is 5 – 7 mm or 6 – 8 mm – and your organism’s structure is 6.5 mm), or with relativistic characters (e.g. species X tends to be shinier than species Y – and of course you have only one), or uses male characters only (and you only have female specimens), but most keys work amazingly well.

An important activity after arriving at an identification from a key is to read about the species identified and ask: does this information fit what I know about my specimen? In other words don’t blindly accept that just because you have struggled through a key, you have reached the correct conclusion. I have found that when you are right, it feels right. If you are unsure, better double check or (better still) get an expert to confirm your identification if one is handy. 

I have been collecting dung beetles for a while and have tried to force scarabs (or near scarabs) into the wrong key before. This never works. Well today I discovered I was doing it again. After forcing this 2013-12-10 11.35.17-1little guy again and again into Gordon and Skelley (2007) Aphodiini of the United States and Canada with unhappy results, I finally went to American Beetles Vol. 2 and found the reason I was getting such poor results was that this beetle is in the tribe Eupariini, not Aphodiini. If I had used the key in the front of Gordon and Skelley (2007) I would have discovered this right off the bat. The cool thing is the correct key is available for download from the Smithsonian – alleviating this problem for all sorts of folk throughout the country. Tomorrow I hope to enjoy this key…

A bit of animated lichen

On this fine, first day of December 2013, Kelly Tindall and I were out and about in Milan, TN. Like most of you when outdoors, I was watching tree bark very closely and saw a tiny piece of lichen move with that characteristic ‘hidden insect’ motion used by stick insects and the like.

A bit of animated lichen

A bit of animated lichen

Now, I always enjoy a good nature blog post where the writer is able to name everything in the blog post no matter how obscure. I thought that my finding an animated bit of lichen on 1 December 2013 on the bark of Magnolia grandiflora was pretty cool. I knew I could not name the lichen species involved in the shelter, and figured the tiny larva was going to remain unknown. Still that insects (e.g. Cercopidae and Trichoptera) can build shelters is amazing and that these shelters can be camouflage also is a two birds/one stone sort of deal – and I thought this provided an opportunity to share that nugget of wonder. Another cool bit is that the lichens appear to remain alive, so the insect could actually be a dispersal mechanism for the lichen…

The insect was so tiny, but i wanted Kelly to see it move, so we ended up bringing it home. In the truck on the way home we played guess the larva. I was driving (a major handicap in this game) and Kelly quickly deduced it was Neuroptera

When the lichen bit is flipped over and you wait a bit you can see the insects face (from underneath).

When the lichen bit is flipped over and you wait a bit you can see the insects face (from underneath).

and remembered that some Chrysopidae have debris carrying larvae. When we got home, I ran to the microscope to see how amazingly cool this insect is. The photo at left is taken holding my cell phone to the eyepiece of my microscope – it is what you get. It would be better if you could come over and see it, but the photo is easier to share. I tried to take a video of it moving under the microscope, but that was awful. Tomorrow I will put the insect out on a lichen covered tree.