A pine tree is not an obvious butterfly plant, and that is what makes this one memorable. The eastern pine elfin, Callophrys niphon, is a small brown hairstreak whose caterpillars feed on pine, and the males sit in the sun at the top of young trees waiting for females. It is the species French Wikipedia calls the Lutin des pins, and BAMONA keeps the older genus name Incisalia as an alternate.
Identification in words
BAMONA describes it as tailless, with a dark brown upperside, the female with dark borders. The underside is banded with dark brown, and the hindwing has a gray band near the margin outside a row of black crescents. Those underside bands are what a person sees most often, because elfins perch with the wings closed. The wingspan is 1 to 1 1/4 inches (2.5 to 3.2 cm) in BAMONA and 22 to 27 mm in Wikipedia.
Wikipedia compares it to the western pine elfin and notes that the eastern species has two dark bars in the forewing underside cell, where the western has one, along with strong patterning below. Being tailless also separates it from Henry’s elfin, which carries a short tail and often an orange tinge on the outer wing.
Range
BAMONA gives Nova Scotia west to eastern Alberta, south to northern Texas, the Gulf Coast and northern Florida. Wikipedia words it as most of the eastern United States and the southern parts of the Canadian provinces, and says within that range the butterfly keeps to sandy areas with pine trees.
Habitat and behavior
Habitat in BAMONA is areas with small to medium pines, such as forest openings and edges, and old fields. Males perch on the tops of pines in the sun to find receptive females. Adults take nectar from many flowers. BAMONA lists blueberry, cinquefoil, chickweed, common milkweed and white sweet clover, and that is a notably ordinary list of plants that grow along any sunny field edge.
Caterpillar host plants
BAMONA names various hard pines, including scrub pine (Pinus virginiana) and jack pine (P. banksiana), and the soft white pine (P. strobus). Wikipedia lists jack pine and white pine. The two sources do not agree on where the egg goes. BAMONA writes that eggs are laid singly on new needles of young trees and that the caterpillars feed on the needles. Wikipedia writes that females lay eggs singly on flower buds and that the caterpillars eat both the flower and the developing seedpods. Neither claim is contradicted by the other source on any pine species, so both are given here, and the reader who wants to search for caterpillars should expect to look at new growth and cone buds on young trees.
After feeding, the chrysalids hibernate. Wikipedia says they sit in loosely formed cocoons beneath litter below the plant, and BAMONA says adults emerge in the spring.
Flight season
BAMONA gives one flight from March to June. Wikipedia splits it by latitude: March to April in the south and mid-May to early June in the north. A reader on the Gulf Coast should expect the early end of that window, and a reader near the Canadian border the late end.
Status
BAMONA’s global rank is G5, demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery. Conservation is listed as not usually required and management needs as none reported. Wikipedia’s infobox agrees with a secure status from NatureServe. No source consulted lists a state-level protection for this butterfly, which is the opposite of the picture for the eastern lupine feeder in the Persius duskywing entry, where decline is documented.
What a gardener can and cannot do
This is a rare case where the caterpillar plant is a tree that many yards already hold. A gardener within the range who keeps young pines in a sunny, open spot matches the habitat described, small to medium pines in openings and edges. A nectar patch is easy to add too, since BAMONA names blueberry, cinquefoil and common milkweed among the flowers adults visit in spring.
The limits are real. No source here reports an elfin using a planted yard pine, and a mature shaded pine stand does not match the young-tree habitat. Pesticide advice is not part of the species sources, though the butterfly garden guide covers it generally. A gardener should treat young pines as plausible habitat, not as a lure.
The Moss’ elfin on rock and the pine satyr of high-elevation pine forest are two other butterflies tied to a single kind of ground, and both show how narrow the match between butterfly and landscape can be.
Common questions
What is the Lutin des pins?
It is the French Wikipedia name for Callophrys niphon, the eastern pine elfin. French Wikipedia writes the genus as Callophrys with Incisalia in brackets, the older genus name that BAMONA lists as an alternate scientific name for the same butterfly.
How do I recognize an eastern pine elfin?
It is tailless and dark brown above, and the female has dark borders. The underside is banded with dark brown, and the hindwing has a gray submarginal band outside a row of black crescents. Wikipedia separates it from the western pine elfin by two dark bars in the forewing underside cell, where the western species has one. The wingspan is 1 to 1 1/4 inches (2.5 to 3.2 cm).
What do the caterpillars eat?
Pine. BAMONA names hard pines such as scrub pine (Pinus virginiana) and jack pine (P. banksiana) and the soft white pine (P. strobus). It says eggs go singly on new needles of young trees. Wikipedia says eggs go on flower buds and that caterpillars eat the flowers and developing seedpods, so the two sources describe the feeding site differently.
When does it fly?
Once a year in spring. BAMONA gives March to June across the range. Wikipedia says March to April in the south and mid-May to early June in the north. Chrysalids hibernate and adults emerge the next spring.
Is it threatened?
Not as a species. BAMONA gives the global rank G5, demonstrably secure, with the usual caveat that it may be quite rare in parts of its range. Conservation is listed as not usually required, and management needs as none reported.
Will pines in my yard bring it?
Possibly, in range. The sources report habitat, small to medium pines in forest openings, edges and old fields, and do not report garden visits. A few young pines in a sunny open spot match the habitat description. Whether the butterfly finds them is not documented.