Monday, June 20, 2016

Plociopterus ain't no myrmecophile!

In a paper just published in Coleopterists Bulletin (pdf here), Mariana Chani-Posse and I moved two myrmecophilous species of “Xanthopygina” in Philonthina. Both species had been described by Wasmann 1925 in the genus Plociopterus. And so for the last 90 or so years, Plociopterus was known to have two myrmecophilous species. Unfortunately, several authors discussing the origin of myrmecophily in Staphylinidae (or at least specifically for Staphylinini) was using this as an example of independent evolution of myrmecophilous life style. The problem was that nobody had checked the specimens since the original description, because none of those species belonged in Plociopterus. They are Belonuchus (at least until the genus is revised) and for those keeping score at home, this is also the wrong subtribe…

The moral of the story is this: people make mistakes and generic concepts change over time, as well as our understanding or higher level relationships. As I have mentioned earlier, If somebody described a taxon 100 years ago, chances are that this taxon now belongs in a different genus or is a synonym of something else. Using raw data in biodiversity studies without going through the lens of a revision is almost guaranteed to lead to erroneous results.

As a side note, Plociopterus is in terrible need of a revision. There are multiple new species awaiting description and many taxa that have to be placed in synonymy. But the genus has an infamous history among Xanthopygina workers: at least twice people have started its revision (both in the lab of my late PhD advisor, Steve Ashe) and both times people abandoned the effort. Perhaps third time’s the charm?

Wednesday, June 8, 2016

Thoughts on studies using taxonomic data

tl;dr version: Your results are mostly wrong. Unless someone has revised (in a taxonomic sense) the species you are using in your study.

Longer version: People make mistakes. When we describe a new species, or a group of new species, we sometimes place them in a taxonomic rank (let’s say genus for argument’s sake) we think is correct but we cannot be absolutely sure, unless we have a very thorough phylogenetic analysis. Phylogenetic analyses are awesome, but in the age of genomics they cost a lot of money. And in many cases (incorrectly in my view), building that phylogeny is beyond the interest of the person describing these taxa.

Now consider that the majority of species were described a long time ago, long before people were thinking about phylogenetic relationships. Also, some of the early (we are talking 19-early 20th century here) taxonomists were not specialist per se, and would describe species among many different families of insects, thus not really knowing where those species belong. So, in many cases, if during the last 40 years nobody has taxonomically checked (=revise) the species you are are using, chances are that these species are: (a) synonyms of another species; (b) placed in the wrong genus or (c) placed in the wrong higher rank.

Example: in 2004 I published with several colleagues a study on when (day or night) rove beetles were active on Barro Colorado Island, Panama. If you want to read the details, the paper is here, but to save you from a lot of trouble, I just set up a flight intercept trap and for a period of 12 days I was sampling at dawn and dusk. Here is part of table 1:

My 2004 self made two three mistakes there. What we thought was Dysanellus ended up being a new genus of rove beetles described as Zackfalinus and Dysanellus is restricted to the southern part of South America. Likewise, what we thought was Philothalpus ended up being Oligotergus, because nobody had looked up before how messed up the generic limits were in Philothalpus. UPDATE: Adam Brunke correctly reminded me that all specimens identified as Quedius were indeed Cyrtoquedius based on this paper.

What I am saying is this: if you are pulling data out of a digitized collection of GBIF, good luck. I hope a taxonomist was interested in the taxa you want to use.

Of course, this idea is not new. Meier and Dikow (2004) have said this much more eloquently. 

Monday, June 6, 2016

Hiding place

Every time I need to finish a manuscript I have to find a hiding place: a place where I am going to take my laptop and a bunch of papers and write. Although I can write in my office or at home, when I need to really focus to finish that paragraph in either a paper or a proposal, I have to get away. No matter how much I clean my office from distractions, there is always something: a specimen, a knock on the door, a stupid post-it note on my computer screen. Today my hiding spot is in unused biology lab. The gentle him of the refrigerator and the mowers outside provide enough white noise to write and even take breaks from writing to write this little note.  

Tuesday, May 31, 2016

Celebrating TN Valley beetles

During the spring semester a super dedicated team of undergraduate students and I curated (pin, label, database and identify) nearly 5000 specimens of beetles from the Tennessee Valley. Our main field sites are in the Tennessee River Gorge Trust and Lula Lake Land Trust. Over the next several weeks, I will start posting on my Twitter account several photographs of charismatic beetles from these two locations.

All of beetle photographs can be found online on this page. Below is a just small screenshot of that page.

Stay tuned for more photographs!

Tuesday, February 16, 2016

Collecting in Winter

For the past several months I have been collecting beetles at Lula Lake Land Trust and at the Tennessee River Gorge Trust. I started near the end of spring and I plan to do a full year of collecting in each site. Winter is here and even though it is not really cold (by midwest standards) the temperature is hovering below zero Celsius for many days in a row.

I have to say I love doing field work during this time of the year. Yes, it is not super-productive but it is so much more pleasant: no ticks or chiggers, no 90% humidity and I am not covered with mosquitoes. And the traps have some very interesting beetles in them. Granted, the diversity is rather low and I have to sort through mountains of flies to actually see the beetles, but I will take it.

Here is a typical pan (out of eight) of my Flight intercept traps (FIT). This picture shows insects that fell in the pan between January 5 to February 5.

Collecting with Lindgren traps can be a bit more tricky. During the past month we had some very windy/wet conditions that resulted in having my propylene glycol being washed out of the trap. The water that remained in the collection cup did not play very well with the subfreezing conditions and resulted in this:

However, underneath all this ice, there were beetles, including several rove beetles.

If you are interested in seeing what we have been collecting, all of our specimens are included in our Symbiota database that recently surpassed 10,000 beetle specimens. 

Friday, October 16, 2015

How do you know a species is new to science?

Students often ask me, how does one go about a describing a new species? It's easy, you just have to know what has been described before! I am kidding, of course. Knowing what has been described before is by far the hardest part of describing a new species.

Here is an example: I work with a group of rove beetles belonging in the subtribe Xanthopygina, a group of 30 or so genera and ~400 species. To be able to describe a new species with confidence, I need to know how all 30 genera and all 400 species look like. Why? Because the generic limits that we recognize today might have been more relaxed in previous years, and species currently in one genus might actually belong in another (this has happened multiple times to me in the past). So if somebody wants to describe new species in e.g. the genus Plociopterus Kraatz, seeing just the existing species in Plociopterus is not good enough. People of course describe like that all the time (or by just finding a species in a "new area"), but this leads to sloppy (at best) taxonomic work.

Over the past few years I have been working with myrmecophile Xanthopygina. One of the most prominent early 20th century myrmecophile entomologist was Wasmann. His collection ended up in Maastricht and this week I was able to finally see all of the Xanthopygina species he described.

This post-it note was glued on my monitor for the last three years. A constant reminder that there were still species described in Xanthopygina that I had not seen. But now this over and I feel much better describing new species that are in or close to Plociopterus. And I have to say, I did get rewarded for insisting to see these species: one of the two  both species described by Wasmann probably belong in a different subtribe altogether.

Sunday, October 4, 2015

Revision and new species of Trigonopselaphus

 I recently published the revision of Trigonopselaphus, a genus that includes some of the largest rove beetles known, with sizes ranging from 30-40 mm (trust me, this is huge size for rove beetles). The paper is available here. Previously I had blogged about the loss of the type for one of the species, Trigonopselaphus herculeanus. That species was described by Laporte and was lost in the Smithsonian fire back in the mid 1800s. So, as a good taxonomist that I am, I designated a new type (called a neotype) for that species.

I also described a new species from Ecuador and Peru, named Trigonopselaphus diplopegus. The epithet refers (of course) to the specific structure of the genitalia. But while I was working on this paper, these beetle heads looked oddly familiar.  And finally, a few days ago, I got it: anybody else see the resemblance?

Image of Blue alien head from here
Maybe little blue aliens do live among us after all.