Elfins belong to the subfamily of butterflies called hairstreaks. This group is classified in the worldwide    Family Lycaenidae which also includes blues, coppers and metalmarks. Many of the hairstreaks, as their name suggests, bear hairlike extensions at the rear of their hindwings. The group of hairstreaks we call elfins have no such “tails”, instead bearing a tornus on their hindwing, a rounded globular extension to the wing projecting down perpendicular to the tails of other hairstreaks. Elfins are small, unobtrusive butterflies, adorned in camouflaged colors of browns and grays. All four of our elfins fly early in the spring. Most species first fly in March, but the Western Pine Elfin appears a bit later in early April, and is on the wing through late July at higher elevations.

The Western Pine Elfin occurs throughout most of the western half of the US and Canada. In Canada the species also occurs across the continent to the eastern seaboard, dipping barely into the northern edge of several eastern States. In Washington, I. eryphon occurs mostly east of the Cascade Mountains, in a band along the eastern foothills of the Cascades, across the northern tier counties and south along Washington’s eastern edge into the Blue Mountains. It also occurs in several spotty outliers, most significantly in Mason County west of the Cascades.

Incisalia eryphon is found in open forested areas where pine trees, particularly yellow pine, grow near meadow openings with blooming nectar flowers. The elfins are associated strictly with the soft, light green new growth branch tips. Eggs and larvae can sometimes be found by searching the soft new branch tips of small trees in areas frequented by the adults. All four of Washington’s elfin species hibernate through the winter in the chrysalis stage, enabling them to emerge early in the spring. Males emerge first, usually 1 to 2 weeks before the females, staking out the best perches near pine trees. From this perch they aggressively defend their territory against other males, returning to the same place repeatedly. After the females emerge and mate, they lay their eggs singly on the soft new-growth branch tips of the host pine tree. The eggs are usually tucked in close at the base of a pine needle, on the protected underside of the slanted needle. After hatching, the tiny camouflaged larvae feed on the tender new-growth needles at the branch tips, and do not make nests. The larvae do not wander, staying directly on their food plant, growing rather slowly and maintaining their camouflage throughout. The final instar is green with yellow stripes, blending well with the needles on which they nest and feed, and finally pupating approximately seven weeks after the eggs were laid. The pupae hibernate through the summer, fall and winter to eclose the following spring.

Dorsally all four of Washington’s elfins are mostly solid brown or reddish-brown but, because dorsal wings cannot easily be observed in the field, ventral wing markings are more useful for identification. Of our elfins the Western Pine Elfin is the most easily identified, by the dramatic dark brown zigzag lines on the underside of its hindwing. The Western Pine Elfin is so distinctive that it can be confused only with the Eastern Pine Elfin, which does not occur in this region.

Adults take nectar from available flowers, and males engage in a perch-and-wait strategy for females. Western Pine Elfins are fairly inconspicuous and easily overlooked, although once spotted the zigzag pattern on the ventral hindwing seems surprisingly gaudy. All elfins perch with their wings closed over their back, so dorsal wing surfaces can be observed only in the hand or in flight. A lepidopterist sampling the species early in the flight period is likely to find only males, and gravid females may not be present until 2 to 3 weeks later. Female behavior is usually easily spotted, as they spend much of their time flying between nectar sources and do not engage in perch-and-wait or fly-out- and-challenge behavior.

All photos by Dave Nunnallee

G’num2005Vol6No3