Sunday, August 30, 2015

A second Michigan Locality for the Giant Spreadwing

For many years, a few of us wondered if and when Archilestes grandis, the Giant Spreadwing would be found in Michigan.  This giant lestid has been spreading from the SW to the NE gradually, and I believe that it's because of anthropogenic habitat change we are seeing the species farther and farther northward and eastward.  Julie Craves and Darrin O'Brien found a small colony of A. grandis in Wayne Co. ten years ago (2005) [Craves, J. 2006. Great Lakes Entomologist 39 (1&2):88-90].  The small stream in Livonia has had a colony for at least the last decade, but no other locations had been found.  
Yesterday, I was almost apoplectic when I saw a Giant Spreadwing in my front yard.  I went off to get a net, but when I got back it was gone. Drat.  No photo, either.  This species is hard to miss, as it's at least 2x the size of any other Lestes in our area, and deserved of the "Giant" category.  I looked several times afterwards, but did not see the spreadwing again.  Until today.  This time, I walked out into the garden with the insect net -- a movement near the Hydrangea shrub -- and there it was. A female Giant Spreadwing!  I carefully moved closer and snagged the specimen with my net.  Wow! 
I was elated over being able to catch and voucher this elusive species. In my front yard, no less.  Really, that's like being an expert in meteorites and having one fall in your yard.  Twice.  

So, naturally, I had to wonder where this female came from.  It had to be relatively close by, but where?  Aha! County Farm Creek, which is a 10-minute walk from my house.  So, with my D200 and 200mm micro-Nikkor, I walked over County Farm Park (CFP).  Three years ago the county finished the constructed wetlands and the improved creek channel. I walked down to the creek where the water was pooled up, and there, under the overhanging willows, within a minute of arriving at the water, I spotted a male Archilestes grandis! I checked other spots along the creek, and had 10 sightings, 9 males, and 1 female. I watched several males, and they typically flew off to catch a gnat and then return to where they were perched to eat it. I feel as though the female in my yard was an omen. 

Looking at the site, I think the arrival of the Giant Spreadwings is fairly recent, and was possibly facilitated by the improvements in County Farm Creek and the constructed wetlands.  Willows and other small trees now grow on the edge of the banks, shading the stream, and provide ideal perch sites for the damselflies.    The image of County Farm Creek should provide a reference in looking at other small, slow streams elsewhere in lower Michigan.


So, this makes two localities in SE Michigan.  Where else will we find them?
Oh, and the voucher data is: MICHIGAN: Washtenaw Co., Ann Arbor. 2104 Needham Road. 30 August 2015. Mark F. O'Brien.

Wednesday, August 19, 2015

Mapping Is Easy

Now that all of our MOS records have been geo-referenced (thanks to Darrin O'Brien), the mapping becomes a reality.   I am using Google's mapping app to import the data from Excel spreadsheets.  Here are the four species of Calopterygidae in Michigan:

Calopteryx aequabilis Say
Calopteryx maculata (Beauvois)
Hetaerina americana (Fabr.)
Hetaerina titia (Drury)

I think this is going work....

Tuesday, August 11, 2015

Making Progress!

I am now experimenting with using Google Maps and other online sites to create distribution maps based upon MOS records.  Having the entire database geo-referenced is facilitating this aspect of  the Michigan Odonata Atlas.!  This is basically my initial foray into this, so there will be some improvement and changes as I progress.

Aeshna tuberculifera adults.



Thursday, August 06, 2015

Humbling, yet Enthralling

This summer has been spent doing more computer work than fieldwork, in regards to Odonata.  Yes, I would love to be able to go out in the field all summer and play.  Because, while it sometimes is hard work, it's really play.  The work at the computer is important in terms of what the final result will be.  First of all, I thank Darrin O'Brien for his diligence and hard work in geo-referencing over 28,000 records in the MOS database.  Plotting each record on a map is going to tell us quite a bit more than just a shaded-in county for a species' occurrence.  Imagine the map for Ischnura verticalis!
As I was bringing in the data for the coordinates to the MOS database, I suddenly realized that we were having a wee problem. Eighty-five records should have 85 corrections, not 87.  Hmm.  I then realized we had some duplicate numbers in the database.  A duplicates search in Filemaker brought up several hundred pairs of duplicate numbers. I printed out the records, and then found the problems that created the duplicates.  A few were exact duplicates, where  everything was the same.  Those were easily eliminated. A smaller number were errors I had made in assigning numbers to different sets of incoming specimens.  I was able to find the specimens and give one set new (bar-coded) numbers.  The last remaining ones required more sleuthing, and some of those records were entered in 1997!  Transposed numbers and operator errors accounted for most of the problems.  I finally eliminated all duplicates a couple of days ago.  We still have over 28,000 records in the database, and in searching through the collection, I gained some insight into what the "old-timers" did and an appreciation for our fantastic collection.  It was actually a little humbling to see all the places that some people collected, and how many of those same sites I had visited over the past 30 years.  It also pointed out how a well-maintained collection makes the work easier.  Most of our older material is housed in paper triangles.  Anything added within the past 20 years or so is inside clear 3x5 inch mylar or polypropylene envelopes, backed with a card that contains the collecting event information.

The cards are easy to sort through, but the paper triangles are something like playing a physical game of Tetris as they have to be placed in the unit trays in a way that conserves space.    When I look at the specimens, they are a tangible link to the past, not only those that preceded me, but my own as well.

In addition to this, I have had two students cataloging the North American specimens in our collection.  At this point, they have captured data for over 20,000 Anisoptera, and have yet to finish the Gomphidae.  Then, I will start them on the damselflies.  That will probably be another 25,000 records.  In total, including the UMMZ-MOS specimens, that should be around 75,000 specimens from only North America.  It's a pretty damn good collection, and someday we will catalog the other specimens, which should add up to another 100,000.

So, I have been dealing a lot with data this summer, and while I am not out in the field that much, I am gaining more insight into the fauna that we have, and the remarkable collection that we house here at the Museum of Zoology.    If I have one piece of wisdom to impart from all this, it is: Use bar codes!  It makes daata-entry faster, easier, and you avoid the problems that I encountered with the duplicates.  The database is set-up to avoid dupes as we enter the data, but it does not do so when we import a bunch of records.  Lesson to be learned.  Click on the box that enables that check.