Tuesday, April 14, 2015

The Name Game

Male willow catkin in bloom this week (actual size 1")
For all these years, I thought pussy willow was a generic name for the first catkins of spring. Low and behold, I just learned that there really is a willow species by that name (Salix discolor in Latin) but it mostly lives north and east of Montana. So what are these willows growing around here? I don't know - and I probably never will.

That's because 19 or 24 or 25 willow species live here in the Rockies, depending on which plant guide you read. Most willows are highly variable and many hybridize with each other. Correct identification is a conundrum for a non-specialist, and that's a perfect segue to the little willow dart moth (Cerastis salicarum), which just became my first moth discovery of spring.

We know next to nothing about this moth. They are brown, there's one flight of adults in the spring, and the larvae might feed on willows. And, the species was named posthumously in 1857 by a non-specialist named Francis Walker, who was also called a "taxonomic mercenary" and a "taxonomic narcissist."

Willow dart moth, named Cerastis salicarum
in 1857 by Francis Walker
Walker was born four miles north of London in 1809 to a wealthy and educated British family. By the time he had passed in 1856, Walker managed to ruffle the dusty wings of just about every entomologist of his day. You see, a family friend awarded Walker the contract to catalog the British Museum's vast collection of insects. But entomology wasn't his forte. Instead, Walker had a gift for making up names.

Carl Linneaus, the father of binomial nomenclature (giving each species a unique two-word name), described and named about 13,200 species during his illustrious career (9,000 plant species and 4,200 animal species). Most of those names still stand today. Walker, on the other hand, produced names and descriptions for a whopping 46,000 species of insects, including 10,000 species supposedly new to science - and many of his names were utterly useless even as he published them.

Walker attacked the museum's massive project with a "laborious assiduity." For 27 years he doggedly described the specimen at hand when he should have been describing the variety within each species. The result of Walker's industriousness was that he gave a single species many different names, over and over again for nearly three decades. One moth species, for example, was described as six different species under six different names in the same publication. This led the editor of Natural Science journal, in 1894, to coin the term "Walkerism" for giving one species a number of different names. This kind of work needs no comment," he wrote, "it sufficiently condemns itself.” 

Numerous complaints had no effect on Walker's contract or on his boss' continued support. The museum was mostly interested in Walker's production and unconcerned with the resulting taxonomic tangles. Upon his passing in October of 1874, an anonymous obituary in the Entomologist’s Monthly Magazine summed up Walker's life thus:

"More than twenty years too late for his reputation, and after having done an amount of injury to entomology almost inconceivable in its immensity, Francis Walker has passed from among us." 

Francis Walker 1809-1874
Francis Walker 1809-1874
But a little more than 100 years later, a 1980 comparison of accuracy between Walker and the professional entomologists of his time told a different story. Walker's insect names scored an unimpressive 64% correct. Eight of his contemporaries working with the same insect groups scored between 50-67% correct. For his era, Walker proved no worse than some of his colleagues. The same anonymous obituary managed to balance Walker's taxonomic injury against his generous nature,

"Even those who felt most keenly the disrepute into which he brought the entomological section of our great Natural History Museum, will miss with regret his courteous salutation and simplicity of manner."

And so it is, 159 years later I notice a generic moth on an anonymous willow, and I can't name either one without help from specialists. I think back to Francis Walker, and I can't help but crack a smile.