by S. W. Bullington
You might be wondering why a private individual like myself has chosen to create a series of web pages on a fairly esoteric group of flies, about which most people neither know nor care. The short answer is that these flies are incredibly neat, and largely common insects which I know a great deal about, and would like others to appreciate as much as I do. In my opinion there is no reason why amateur entomologists and "collectors" should confine their attention to such types as butterflies, owl moths, and tiger beetles. The robber flies I am covering here can offer all they do and more, in the way of beauty, variability, and sport. Working on them is perfect hobby.
The one thing that has been lacking to make this group popular is a manual. I once had the strange idea, that people worked on a group entirely because of some intrinsic factor, as for example the beauty of the specimens when arrayed in a drawer, or the sport they afforded while being collected. This is true, at least to an extent. But I now know that my thoughts were incomplete. Intrinsic interest alone is insufficient to explain why some groups are popular with collectors and some are not. Past a certain point, the main thing making a group popular is a popularizer. In other words, popularity is a two part equation. First, someone has to take it upon themselves to do the basic taxonomy. Second, someone--usually someone else--then has to present this taxonomy to the public in a way that can be understood. In these pages I will be attempting the second half of this equation.
The long answer as to why these web pages are here is somewhat more complicated, and its roots go back--to filch a phrase from W. H. Hudson--to "far away and long ago," and the first part of the equation given above. In 1978 I began a self-funded revision of one of the genera covered here, Laphria Meigen. At the time this genus was believed to contain 63 species in North America north of Mexico. For those who don't know, a "revision" is a type of generic overview, where the investigator looks at all the available specimens, and all the "literature" or material in print. He then determines how many species are valid, and goes on to redescribe them in a common format, which is usually accompanied by distribution maps, illustrations, and keys. The purpose of my revision was to serve as material for my Ph.D. dissertation.
Although I little knew it at the time, by deciding to embark on this course of action, I had undertaken what in the long run would become a lifetime project, and in the short run would tax my capacities to their utmost. To succeed, I had to accomplish three things before I graduated. First I had to acquire--and understand--the literature not only on North American Laphria itself, but also any papers that might address the systematics of the group world-wide, or their place in the larger scheme of asilid classificiation. The understanding was more important than the acquisition. This was particularly true for the morphology and mechanics of asilid terminalia--for the females as well as for the males. The taxonomy and phylogeny of the Laphria on which I would be working would eventually be constructed using this information. This was a large project in itself, starting as it were from scratch. When I began I had collected asilids for three years as a hobby, and had purchased a few sets of papers on North American flies. But I had never even so much as looked at the terminalia of any species as an aid to its identification.
It is easy to forget that acquiring such understanding takes time, and, what is often overlooked, lots of practice, in the form of writing small papers describing new species, based on terminalic characters. I had almost forgotten to include it here, as from my present vantage point, it has been well over 15 years since I have had all of the North American literature on asilids, and much of that for the world, at my fingertips, and have understood it thoroughly enough to publish at will. But this situation did not come quickly.
In 1978 I was on my own. I could not depend on anyone else for a boost. I had picked the University because of the expertise and advise of my major advisor. At the time he was the only professor at a large university who was familiar with asilids. For my purposes, I could not have picked better, and he has helped me greatly over the years. In particular, one of his passions was--and still is--the collection of the literature for asilids world-wide. Having access to this treasure trove was of inestimable value, and I cannot thank him enough for making it available to me as a graduate student. But his forte was first and foremost ethology. He was not interested in taxonomy.
Second, the project turned out to be much larger than either of us had expected. I had to figure out a way to reduce its size. I expected I would be working with a total of perhaps 3,000 flies. I was soon pleasantly surprised. As a result of requesting material from nearly 60 museums, in short order I received nearly 20,000 specimens, all neatly pinned over tiny labels. Each fly usually had several of these labels , handwritten or printed with characters so small that to be read the labels had to be removed and examined with a magnifying glass. The flies themselves ranged in size from a little smaller than a house fly to bigger than a queen bumble bee. To sort these to presumed species I would have to examine every specimen individually, at length, under a dissecting microscope.
I want to elaborate on this last point. Not only would I have to match each specimen character for character with a standard, the whole basis of my revision was to be the fine structure of the terminalia. "Terminalia" is a collective term for the internal genitalia and external sclerites (such as "claspers") associated with them. In robber flies these are located at the tip of the abdomen in both males and females, hence the name. In the males the terminalia are primarily external, but as they are fairly complicated and nested in a tight package, it is impossible to discern the constituent sclerites without removing the tip of the abdomen and dissecting them out. The terminalia of the females are less complicated externally, but internally they are associated with spermthecae and a variety of other structures. Thus I would have to remove the tip of the abdomen from many of the flies, macerate them in KOH, examine them closely, and then fix them in a small plastic "genitalia" vials on the pins from which they were taken. Even when conducted in an "assembly-line" fashion, this could take a half-hour per specimen, and, if the terminalia proved unusual in any way, even longer. Assuming 20,000 specimens, half hour per specimen, eight hours of work per day, and a work year of 246 days, this works out to a minimum of five years, just to look at the terminalia. Of course it would not be necessary to process the terminalia of every specimen. But there were many other things that would need to be done as well--as for example the comparisons mentioned above. Other tasks would include tagging each fly with a museum label, running the specimens through long keys, recording the label data, and preparing the identification labels, not to mention the maps, drawings, verbal descriptions, etc. that would be necessary at the species level. Clearly, I had taken on more than I could handle. Something would have to be done.
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