Watching Washington Butterflies with Bob Pyle: Number Twenty Five

Vladimir Nabokov is best known as one of our finest novelists, as well as a great Bluesman: a lepidopterist who specialized in the blues, and whose iconoclastic theories have been supported recently by sophisticated molecular work. But it was also Nabokov who first noted what a large proportion of our northern butterfly fauna originates each year from the South-or so I was told by Charles Remington, cofounder of the Lepidopterists’ Society and my professor at the time. Nabokov, said Remington, figured that as many as fifteen per cent of our summer butterflies arrive by immigration: southern species lacking a winter diapause that expand each summer into the North, via successive generations. Lepidopterists had long recognized that certain species irrupt northward in early spring in the desert, but it wasn’t widely recognized just how many butterflies are northward expansionists.

I am writing near the end of April. Already, a week ago-plus, I watched three Red Admirables nectaring atop high lilacs in my garden. Vanessa atalanta is overwintering farther and farther north as the climate ameliorates, but historically, it has been an annual colonist in the North, depending upon fresh reinforcements from the non-freezing South each spring. A few days later I was in East Anglia in the U.K., watching scads of improbably beautiful Peacock butterflies nectaring on blossoms of blackthorn and bugle in a rails-to-trails nature reserve cut into a chalk ridge in the Fens. Inachus io has a winter diapause: it overwinters in sheds or English houses without central heating, and so it’s already on hand to fly when the weather first turns clement, along with Small Tortoiseshells, Commas, and the hulky overwintering sulphurs called Brimstones. But a little later, Red Admirables from North Africa and southern Europe will show up, and join all of these over the nettlebeds and butterfly bushes. Painted Ladies, of course, do the same thing: emigrate from the southerly latitudes, or immigrate into the North, depending on your point of view. But, as the canny Nabokov early discerned, many other species formerly thought be resident in the freezing zones actually do the same, and then die back in the fall.

A few days after I returned from England, I flew to Lubbock, Texas, to take part in two conferences being held simultaneously on the campus of Texas Tech University. One was a meeting of writers, my main reason for going. But, happily, the other was the Texas Pollinators’ PowWow-a happy gathering of all manner of good folk (beekeepers, farmers, entomologists, Master Naturalists, botanists, gardeners, conservationists, and others), all concerned with the well- being and future of pollinating insects, bats, birds, and other go-betweens for male and female flowers. I gave a talk entitled “Pollinators, Plants, and People on the Edge of What’s Left”- a pictorial plea for taking careful stock of who’s using what, before attempting to reorder the plant communities on damaged lands. Then I attended the Sunday field trip, wherein nearly half the attendees took to the countryside to see what pollinators they could find in the wild.

The focus of the field trip lay south of Lubbock, in the heart of the Llano Estacado, or Staked Plains, a huge, high plateau roughly bounded by the Pecos and the red Permian plains. It may have been so named by Coronado for the many yucca stalk “stakes” that punctuate the wide flats, or for the caprock escarpment to the sides. Our focus was a private family preserve known as Tahoka Lake Pasture-an historic cotton-growing and sheep (later longhorn cattle)- pasturing ranch that has been dedicated now to nature conservation on the mesquite uplands and alkali playa in the bottoms.

In the wind and sun of early spring, I went out with several groups into the yucca, cactus, mesquite, and sere grasses, seeking early pollinators on the purple Tahoka daisies, red Gaillardia, and other spring wildflowers that benefited from recent rains. Dodging ticks and rattlesnakes, as the temperature rose, we learned bee-study and collection techniques from renowned bee biologist and photographer Sam Droege. Cassin’s Sparrows skylarked and roadrunners dashed. But I admit to drifting off with my net on each outing to see what was flying in the way of butterflies.

In the end, I tallied sixteen species, encountered in this order: Reakirt’s Blue (Echinargus isola), Sachem (Atalopedes campestris), Checkered White (Pieris protodice), Orange Sulphur (Colias eurytheme), Clouded Sulphur (C. philodice), Black Swallowtail (Papilio polyxenes), Common Sootywing (Pholisora catullus), Common Checkered Skipper (Pyrgus communis), Cloudless Giant Sulphur (Phoebis sennae), Sleepy Orange (Eurema nicippe), Gray Hairstreak (Strymon melinus), Variegated Fritillary (Euptoieta claudia), Gulf Fritillary (Agraulis vanillae), Western Pygmy Blue (Brephidium exilis), Dainty Sulphur (Nathalis iole), and Fatal Metalmark (Calephelis nemesis), plus four or five nymphs and whites I saw from the truck that could not be caught or identified-potentially anglewings, tortoiseshells, checkerspots, and others.

Funnily enough, I had just been telling folks about how, on the butterfly Big Year, I had found a colony of Fatal Metalmarks lurking in the dappled shade beneath old- growth salt cedar (aka tamarisk) along the Lower Colorado River in California; whereas it is often said that this introduced plant supports no life of interest in its dense stands. Just then, third-grader Madelynn emerged from the thicket of salt cedar before us with a Fatal Metalmark in her net! This proved to be a Lynn County record, and one of the two or three northernmost records ever for this species. It was also one of the few stay-at-home, resident species encountered all day.

Because the main point of this story is that, of the list of species enumerated above, almost every one is an increaser, or “weedy species”, and an irruptive emigrator-one which is common in the South, utilizing several or many larval hostplants, capable of producing an early spring generation, bursting out, and then leapfrogging north through successive generations until the continent is largely filled with their shimmering forms. That’s not to say that some of them don’t stay behind; most of these species would probably be found here all summer and into the fall. But except for the metalmark, the Black Swallowtail, and perhaps the sootywing, all of the others listed above are blast-off butterflies: generalists capable of rapid increase in the spring, and if conditions are right, pioneers of the great wave of immigrant butterflies infilling the continent in months to come. Potential antecedents, in fact, of our own Washington butterflies. There, I’ve finally gotten around to “Watching Washington Butterflies”: our summer in-fillers come from somewhere, and ultimately, it might as well be from the Staked Plains of Texas!

Now some of these haven’t appeared here yet-Gulf Fritillary, Cloudless Giant Sulphur, and Sleepy Orange-though they may well turn up in years to come. Others have been very rarely encountered in Washington: we have only one record each for Reakirt’s and Pygmy blues and Dainty Sulphur, two for Variegated Fritillary, and a handful for Checkered White. But our Orange and Clouded Sulphurs, Common Checkered Skippers, and Gray Hairstreaks may well have Tex- an origins each year, or at least be reinforced from that direction. And this entire list-with the exception of the regionally limited swallowtail and metalmark-may well appear on our state checklist eventually, as the warming continues. And that’s why I feel I’ve been making a visit to the butterfly factory! Next time you see a Sachem or a Checkered Skipper, stop to think: its ancestors may well have been Made in Texas!

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