Watching Washington Butterflies With Bob Pyle: Number Eleven

If you happened to open the next-to-latest number of the Journal of the Lepidopterists’ Society, you will have found an extraordinarily thorough paper by Nick Grishin and Chris Durden, describing a brand new species of butterfly: Strymon solitario, the Big Bend Scrub Hairstreak. For years, various collectors had suspected there was something different about certain populations that had generally been confused with another, more widespread hairstreak. Investigating the situation in detail, Grishin and Durden found that these Texan butterflies did indeed differ-in ecology, host, range, and-very subtly-in physical makeup. Thus, a new species was born, at least in the systematic sense. It is not the only case of its kind.

In a recent conversation, I mentioned to a friend that new species of butterflies are still being discovered, even at this late date. “That’s amazing!” she said. “I thought that with birds and butterflies, it had all been done. But it sounds as if you don’t even have a solid foundation yet.”

Actually, as I went on the explain, we do have a solid foundation for our science. Be- tween the Pelham Catalogue, butterfliesofamerica.com, relatively recent books on the butterflies of British Columbia, Oregon, and Cascadia, and now what I refer to as “Cascadian Cats-that is, Life Histories of Cascadian Butterflies by Nunnallee and James-we have a firm basis indeed for our regional butterfly studies. Indeed, that is what enables us to pick out new species that have not heretofore been obvious: what are known as “cryptic,” or hidden, species.

A cryptic species is a kind of organism that looks so much like another, known type that it literally remains secreted in the background-or foreground-of the faunistic picture. Cryptic species breed true, in spite of being almost identical to others that may fly in the same time and space. That is, they have achieved genetic isolation without diverging very much in appearance from their sibling relatives. As such, they can be extremely difficult to discern, let alone to demonstrate, as discrete biological species. Eventually, reliable field marks may reveal themselves. In the meantime, most of us feel as though we just have to take the word of the cognoscenti, hoping that the kings have clothes. Yet, if we pay attention, it is usually not too difficult to understand why such distinctions are made, and to judge them for ourselves.

To be sure, some dramatic discoveries have been made in modern times that are wholly unique: the Sandia Hairstreak of the Southwest, found in a New Mexico 4-H collection in the late ‘fifties; the Uncompahgre Fritillary, discovered by two graduate students hiking the high San Juan Mountains of southwest Colorado in 1979; and so on. But more likely to be uncovered in this day and age are species that have hitherto remained invisible against the matrix of other, often common, and look-alike kinds of butterflies.

Unlike such outright discoveries of unique new types, the detection and description of cryptic species re- quires painstaking observation on several levels: subtle clues of appearance, yes; but also ecology, life history, distribution, host plant fidelity, voltinism and phenology (number and timing of generations and development), and any other attributes you can think to watch and measure. Long specimen series are generally necessary for comparing variation in pattern and morphology. Genitalic dissections sometimes provide the tip-off, and nowadays, DNA sequencing becomes more and more important and revealing.

Good examples of early cryptic species can be found in the satyr genus Le- the. If you look at the Klots field guide (1951), only three species are recognized: the Pearly Eye, the Creole Pearly Eye, and the Eyed Brown. But by the time of the Kauf- man field guide (2008), we find the Northern and Southern Pearly Eyes as well as the Creole; and the Appalachian Eyed Brown as well as the original: five species from three, all of which have subtle but consistent differences. Another fine example is Hessell’s Hairstreak, described in 1950. Prior to that, it was conflated with the widespread and common Olive Hairstreak. Sid Hessell and others had long noted that certain “Olives” had a grainier texture to the scales below, and showed up only in certain are- as and habitats. This steered them ultimately to the correct deduction that Callophrys hesseli feeds solely on white cedar in near-coastal eastern swamps, as opposed to C. gryneus, which feeds on eastern redcedar over much of the East (and, as we now know, on various other junipers and cedars throughout much of the country).

In more recent years, some other species pairs or triplets have been created from what was long thought to be just one, e.g. the Eastern, Canadian, and Appalachian Tiger Swal- lowtails; the Eastern Black and Joan’s Swallowtails; and the California and Arizona Sisters. In each case, perceptive and dedicated sleuthing succeeded in revealing reliable, if difficult, dis- tinctions.

Sometimes, the task consists of sifting the genuine, genetically separate entities from a mass of variation once oversplit and more recently lumped together. The classic example here would be the greater fritillaries. Holland’s Butterfly Book recognized 47 species of Argynnis in 1898. These names were later rationalized to the point where the dos Passos checklist of 1964 contained only thirteen species of Speyeria, as the genus was then called.

Since then, one of the lumped entities (hesperis) has been re-elevated, and another (carolae) named, as full species. So fifteen American Argynnis (now in ascendency again!) are currently recognized.

And this work goes on. The famous (and federally endangered) Karner Blue was believed to be a full species by everyone from Vladimir Nabokov (who described it as Lycaeides melissa samuelis, but became convinced of its distinctness) to the grandfather of its conservation, Robert Dirig. At last it has been accorded that status, after spending half a century-plus listed as a “mere” subspecies of the Melissa Blue. (For the even more famous (and extinct) Xerces Blue, things have gone the other way. Long considered a distinct species, it is now thought to have been a highly distinct subspecies of the Silvery Blue.) The newest cryptic species teased out of the American checklist has just landed on our doorstep in the latest issue of The Bulletin of the Allyn Museum # 163. John and Tom Emmel (who have long worked to bring order to the highly variable wood nymphs) and Sterling Mattoon have erected a brand new entity they’ve named Cercyonis incognita, which would translate as the “Nameless Wood Nymph.” It is very similar to both the Dark and Great Basin Wood Nymphs (C. oetus and C. sthenele), but breeds true in crossing experi- ments with both. The fact that it drops its eggs (like C. oetus) instead of affixing them to the host grass (like C. sthenele) suggests that it is probably more closely related to the former. Habitat, range, and looks all figured in.

So where do we go from here? The parade of cryptic species is certainly not over. I suspect that the Red-spotted Purple will eventually be recognized as a distinct (but frequently hybridizing) species from the White Admiral, and that the eastern Limenitis astyanax may hive off its southwest cousin, arizonensis, as a sibling species. The Colorado Skipper has emerged from the Common Branded Skipper, and more of its “subspecies” may follow. Charles Remington once described Papilio “gothica” as a cryptic species separate from the Anise Swallowtail, and while this was not accepted, there may yet be another biological entity hidden within P. zelicaon. And there are bound to be other cryptids lurking deep within the meadows, fields, and checklists.

For me, the most exciting work of this sort going on in the Northwest today has to do with the dot- ted blues (Euphilotes) and scintillated blues (Plebejus acmon/lupini group). A closer look at these diminutive beauties and their (mostly) buckwheat hostplants is turning up much more diversity than we thought we had.

Watching Washington Butterflies (1974) listed only three members of these genera, as recognized by Pyle and Pelham at that time in the state. After the research of Merrill Peterson, Andy Warren, David Nunnallee, David James, Paul Opler, and others, looking at insect/hostplant co- evolution, life histories, and many other aspects, that number is rising. It is likely to approach ten species before they are finished, and we may even have a truly endemic species, unique to Washington, in the Spangled Blue of the High Olympics.

We all like stability in our field guides and checklists, and sometimes changes can seem irritating, if not downright arbitrary. But the truth will out, and so it should. Butterflies have always been among the best and most beautiful canvases of evolution-for Darwin and Wallace, Bates and Beebe, Rothschild and Jordan, and all the other seers and seekers since. When a new cryptic species emerges from the tangle of life, it is yet another gift of diversity to

those of us who care about such things. How exciting, that our state is such a living laboratory of biological understanding; and how exciting that butterflies have so much to teach us still.

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