Let’s be honest about the genus Callophrys: with a few green exceptions, these aren’t exactly charismatic butterflies.
Commonly known as “elfins and green hairstreaks,” Callophrys butterflies invariably perch with their wings folded closed above their bodies, at which point they become about the size of a penny – and only somewhat more ornate.
The Callophrys (KA-loh-friss) have never inspired poetry or gained much traction on social media. They’ve not been a cause célèbre of demonstrations or protest marches. Nobody’s out there shouting, “Save the Callophrys!”
Except maybe me, because I’ve come to admire the Callophrys as near-perfect insects. Tiny and gossamer, these butterflies nonetheless express big and enduring ideas in nature, including human nature.
First is intimacy. Once you locate a Callophrys species, perched on a twig or a flower, it will usually allow you to approach and sit in its good graces, which is unusual among butterflies. After some time your Callophrys will indeed depart the scene. But if you are like me, it will usually leave before you do because it is hard (perhaps heartless) to turn your back and walk away from one of these endearing butterflies.
Rarely are we so close and unobtrusive to wildlife, especially among airborne animals. Sitting with a Callophrys butterfly, watching it sip nectar or lay an egg, seeing it interact in the most fundamental ways with the world, feels like some sort of guilty pleasure of which I might not be worthy. These encounters don’t make insects any less different from us, but they certainly make them less remote and otherworldly.
Next is diversity. Depending on whose unsettled taxonomy you prefer, at least three dozen Callophrys species live in the world (perhaps many more), mostly in boreal and temperate regions, including two dozen or so in the Americas. Some Callophrys species are generalists, laying their eggs on varied host plants, on which the caterpillars will feed and grow; others are specialists with but a single host.
Regardless of their dietary inclinations, or actually because of it, Callophrys exemplify one of the greatest relationships in the history of life on Earth: the shared evolution of insects and plants. At its most basic, insects get food and plants get pollinators. As it turns out, moths and butterflies (order Lepidoptera) tend to prefer angiosperms, owing to their softer, more nutritious leaves for the caterpillars and greater floral diversity and nectar abundance for the adults.
But some Callophrys go for gymnosperms. Although rare among butterflies, the bond between Callophrys and conifers is perhaps my favorite thing about these butterflies. For one thing, it embodies the charm of the obligate, an intimacy between two organisms (although conifers in this case get little if anything from the relationship).
Hessel’s hairstreak (Callophrys hesseli), for example, lays its eggs only on Atlantic white cedar (Chamaecyparis thyoides) and nowhere else in the world. You might find the cedar and no hairstreaks, but you will never find a Hessel’s hairstreak far from Atlantic white cedar. I have encountered the two species together across the full extent of their shared range – a coastal plain and inland strip running from the Gulf of Mexico to southern Maine. Where most people might see a distribution lying within the megalopolis known as the Eastern Seaboard, I instead see the only terrain on Earth where a little butterfly might find its essential tree.
Closer to the academic home of the Field Naturalist Program, one of the most elusive butterflies on the continent, bog elfin (Callophrys lanoraieensis), is obligate on black spruce (Picea mariana) at woodland bogs across northern New England and adjoining Canada. At the relatively few sites where it is known, bog elfin is virtually unknown – on the wing as an adult for only about two weeks from late May to early June. It spends the rest of its days on spruce at the bog as either egg, larva, or pupa (chrysalis), all of which are also exceedingly hard to find.
As field naturalists, we define a natural community by the sum of interacting parts and processes – a synthesis that helps us know where we are and a synergy that offers us reason, reassurance, meaning, even story. A Callophrys butterfly is really no different. Although it eats only black spruce needles as a caterpillar and sips nectar from rhodora (Rhododendron canadensis), leatherleaf (Chamaedaphne calyculata), and perhaps a few Vaccinium species as an adult, a bog elfin is after all made entirely of the bog – and everything that conspires to be a bog.
And maybe that’s all the story I need. A butterfly the size of a penny unwittingly tells me where I am in the world. Reclusive and rare, a bog elfin is more than a little brown butterfly. Made of needles and nectar, it is a living monument to a bog – from its glacial history to the orchids that will bloom on its mat in the weeks after the elfin and I have departed the scene. Though you can bet that I won’t leave before the elfin flies off.
