Eastern Tailed-Blue

The eastern tailed-blue carries two hair-thin tails on its hindwings and a wingspan of barely an inch, and it spends its days flying low through clover and vetch in roadsides and disturbed fields throughout North Louisiana's 26 parishes looking for all the world like a flying spark. Cupido comyntas appears at every open, weedy habitat in the region from March through November, at roadsides, in lawns, at field edges, in gardens, and gets overlooked constantly because small size works against notice, because it moves fast, and because observers calibrated for swallowtails and monarchs do not register a half-inch flutter as worth stopping for. That proves to be a mistake. Cupido comyntas ranks among the most consistently present butterflies in North Louisiana's open habitats across a nine-month season, and it lands on clover within five feet of anyone willing to approach slowly enough. Cupido comyntas ranges across North America wherever legume plants grow in open habitats, which in North Louisiana means the entire 26-parish region throughout the warm season. Males show iridescent blue on the upperside that flashes in direct sunlight; females show brown with restricted blue at the wing base. Both sexes carry the distinctive tail extensions on the hindwing and the hindwing underside eyespot pattern that names the family. Multiple generations cycle through the warm season, producing near-continuous adult presence from March through November. What the Eastern Tailed-Blue Actually Looks Like The adult spans three-quarters to one and a quarter inches, genuinely the smallest butterfly most North Louisiana observers will encounter regularly. The male upperside shows bright iridescent blue with a narrow dark margin and white fringe along the wing edges. The female upperside shows brown with varying amounts of blue near the wing base, more extensive in spring and fall individuals, reduced in summer. Both sexes carry two thin tails on the hindwing that project backward from the outer hindwing margin. Hindwing underside, visible when the butterfly perches with wings closed, shows pale gray-white with a pattern of dark spots arranged in rows across both wings. Two orange-capped black spots sit near the base of the tails, and a row of dark spots crosses the outer hindwing. That underside spot pattern, combined with the tails and the small size, identifies the eastern tailed-blue in North Louisiana without any similar species to confuse it, no other small butterfly in the 26 parishes carries both the hindwing tails and the orange-capped black spots in the same position. Tails: thin as a hair, black with white tips, projecting three to four millimeters beyond the hindwing margin. At close range on a perched individual, the tails and the orange spots together create the impression of a small insect face at the wrong end of the butterfly, two orange eyespots and two tails that look like antennae. This false-head pattern at the hindwing tip deflects predator strikes toward the expendable wing margin rather than the body, and birds attacking the hindwing tip encounter a piece of wing rather than the thorax. Worn eastern tailed-blues with missing or damaged hindwing margins confirm that predators do strike at the false head regularly. Where the Eastern Tailed-Blue Lives Open habitats with leguminous plants throughout all 26 North Louisiana parishes: roadsides, lawns, old fields, agricultural margins, disturbed ground, garden borders, and any sunny open area where clovers, vetches, or other legumes grow. The eastern tailed-blue tolerates human-modified habitats as well as any butterfly in North Louisiana, thriving wherever its host plants establish in disturbed ground throughout the region. Host plants include various clovers, Trifolium species, vetches, Vicia species, wild indigo, Baptisia species, tick-trefoil, Desmodium species, and other native and introduced legumes. In North Louisiana, white clover and red clover in roadside margins and lawn edges provide the most widely distributed and most consistently used host plants. The abundance of clover throughout the 26 parishes in disturbed ground, lawns, and field edges explains the eastern tailed-blue's presence at essentially every open or semi-open site in the region. The Caterpillar's Year Multiple broods in North Louisiana, producing adults from March through November with near-continuous adult presence through the warm season. Caterpillars feed on the flowers and developing seeds of legume host plants, the same flower-feeding habit as the summer azure caterpillar. Female oviposition targets clover and vetch flower heads rather than foliage, and caterpillars develop inside the flower clusters with minimal visible feeding damage from outside the flower. Caterpillars maintain the same ant-mutualism as summer azures, producing dorsal nectary organ secretions that attract ants and receive protection against small parasitoids in exchange. Finding ant-attended eastern tailed-blue caterpillars on clover flower heads represents the same specialized search as finding azure caterpillars on dogwood, possible with close examination of flower heads in May through October, rewarding with one of the more intimate small-insect natural history observations available in North Louisiana's open habitats. The eastern tailed-blue winters as a chrysalis at most North Louisiana sites, producing the first adults of spring in March from chrysalises that survived winter at soil level in the leaf litter beneath host plant colonies. What the Eastern Tailed-Blue Eats Adults nectar at clover, vetch, and other small-flowered legumes with a persistence that reflects the concentration of host plant and nectar source at the same location. An adult eastern tailed-blue on a clover patch nectars at flowers two to five seconds per blossom, moving through the flower cluster in a regular circuit, returning to previously visited flowers after short intervals. That rapid, low-level nectaring through clover produces the sparking flicker of blue in the grass that most North Louisiana observers register without identifying. Adults mud-puddle at damp bare soil for minerals, appearing at the same mud sources as summer azures in smaller aggregations. Roadside clay puddles in July hold eastern tailed-blues alongside summer azures at productive sites. What Eats the Eastern Tailed-Blue False-head pattern at the hindwing tip serves as the primary anti-predation mechanism, deflecting attacks toward the wing rather than the body. Small size provides secondary protection by making the butterfly a marginal return for most aerial predators. Crab spiders ambush adults at clover flowers. Robber flies intercept adults in open-field flight. Those tails, which look like antennae from the approach angle of a predator coming from behind, complete the false-head illusion. A bird or lizard approaching from behind the resting butterfly, seeing the orange eyespots and the tail-antennae rather than the real head and real antennae, strikes at the wrong end. The butterfly loses tail tissue. The bird learns nothing particularly useful. The butterfly, minus two tails but otherwise intact, flies away and continues nectaring. Eastern tailed-blues with missing tails turn up in field observations regularly enough that the strategy clearly gets tested and frequently succeeds. The False Head in Detail That false-head pattern deserves more attention than it typically receives in species accounts because it represents one of the more elegant anti-predation solutions in the eastern butterfly fauna. The combination of tail morphology and orange eyespot coloration at a specific hindwing location creates a passable impression of a small insect head from the approach angle most predators use: behind and above. Behaviorally, the butterfly enhances the illusion. When perching with wings closed, eastern tailed-blues often move the hindwings in a slow rubbing motion that makes the tails wave like antenna movements. That motion, combined with the orange eyespots and the tail shape, produces a behavioral component to the deception that pure pattern mimicry alone would not. The false antennae wave. The predator hesitates. The butterfly gains time. That waving motion also identifies the eastern tailed-blue behaviorally from other small butterflies at flowers. A small butterfly at clover with wings closed, performing the slow hindwing-rubbing motion: eastern tailed-blue. No other small North Louisiana butterfly makes that specific movement. Finding Eastern Tailed-Blues in North Louisiana Any clover or vetch in full sun at a roadside, lawn margin, or field edge from March through November. The species appears at essentially every open-habitat site in the 26 parishes where legumes grow, making directed searching unnecessary, walking any rural road shoulder with blooming clover in summer produces eastern tailed-blue encounters without any advance planning. For the closest observation, approach a nectaring male at clover slowly from downwind. Males at clover in direct sun hold longer than average between departure flushes, and the iridescent blue of a fresh male at close range in good light shows the color saturation that distinguishes the species from worn individuals and from brown females at the same site. Males at clover also perform their false-head waving motion during rest between foraging bouts, providing the behavioral identification confirmation at close range. The mud-puddling sites where summer azures aggregate also attract eastern tailed-blues, and the two species at the same clay puddle in July produce a direct size and pattern comparison. Eastern tailed-blues measure smaller than summer azures on average, show the hindwing tails, and carry the orange-capped spots near the tail base that the azure lacks. Those differences visible at arm's length at the mud puddle calibrate the observer to both species simultaneously without requiring either species to cooperate with closer approach. Open Habitats and the Eastern Tailed-Blue Reliance on clover and vetch as primary host plants in North Louisiana means the species benefits from the landscape feature most often dismissed as weed management failure: unmanaged roadside and lawn clover. White clover establishes in disturbed soil and lawn areas throughout all 26 parishes without planting, persists through mowing, and blooms through the warm season wherever mowing does not eliminate every flowering stem. That persistence makes clover the most widely distributed and most dependable tailed-blue host plant in the region. North Louisiana roadsides managed by frequent mowing through the warm season reduce eastern tailed-blue abundance at those sites by eliminating host plant bloom. Roadsides mowed on longer schedules, or left with unmowed clover margins, support breeding populations through the season. The choice between a tidy mowed margin and an unmowed one with clover bloom represents, among other things, a choice about whether eastern tailed-blues breed at that site. The butterfly votes for the unmowed clover every time. A lawn with a clover patch, left unmowed in a sunny corner, provides host plant for caterpillars and nectar for adults from March through November without any active management. The butterfly finds it. That covers the whole conservation action at the residential scale: leave a corner of the lawn with clover in it. The tailed-blue handles everything else. The Waving Tails as Field Mark No other butterfly in North Louisiana's open habitats performs the hindwing-rubbing motion that the eastern tailed-blue uses when resting between foraging bouts. The slow, deliberate sliding of the hindwings against each other, making the tails wave in the alternating pattern that resembles antenna movement, identifies the species from any angle where the motion becomes visible. At arm's length at a clover patch, the waving tails on a closed-wing individual showing the gray-white underside name the species before the pattern details register. Observers who do not know the species behaviorally often watch the motion without registering what it communicates, noting "small butterfly at clover, wings moving slowly" without connecting the motion to the eastern tailed-blue specifically. Once connected, that behavioral identification works at distances and light conditions where pattern details fail. A tiny butterfly at clover twenty feet away in flat afternoon light, waving its hindwings: eastern tailed-blue. No other small butterfly in North Louisiana's open habitats produces that specific motion. The Eastern Tailed-Blue and North Louisiana's Legume Flora North Louisiana's flora supports the eastern tailed-blue through a diverse array of native and introduced legumes that occupy different niches in the open and semi-open landscape. White clover and red clover, introduced European species, dominate the disturbed-ground host plant availability at roadsides and lawn margins throughout all 26 parishes. Native legumes, including several Desmodium tick-trefoil species, wild indigo, native vetches, and various others, extend the host plant resource into native old-field and woodland-edge habitats where introduced clovers do not establish. That combination of introduced and native host plant availability means eastern tailed-blues breed in both the heavily modified agricultural and suburban landscape of the lowland parishes and the more intact native plant communities of the upland and bottomland forest margins. The introduced clovers sustain populations through the most disturbed habitats. The native legumes sustain populations through the least disturbed ones. Together they cover essentially every open-habitat type in the 26 parishes. Removing all non-native clover from a landscape, if that were possible, would not eliminate the eastern tailed-blue from North Louisiana, the native legume host plant diversity available throughout the region's less disturbed habitats would maintain the species. Leaving non-native clover in place, however, produces higher density breeding populations at disturbed roadside and lawn sites than the native legumes alone would sustain. Both plant communities contribute. Neither alone covers the full range. The eastern tailed-blue uses them both without much concern for their immigration history. Spring Tailed-Blues vs Summer Tailed-Blues Early-season adults in March and April, emerging from winter chrysalises, tend to show different coloration than midsummer adults in several subtle ways: spring males appear slightly brighter blue, and spring females carry more blue on the upperside base than late-summer females. These seasonal differences reflect developmental responses to temperature and day length during the pupal stage, similar to the seasonal forms of the question mark and common buckeye. Spring individuals also tend to appear at flowering native plums and service berries before the clover begins blooming, which places them at sites where summer observers do not look for tailed-blues, woody native flowering plants at woodland edges rather than lawn clover patches. A March eastern tailed-blue at native plum bloom at a woodland edge represents the same species as the August individual at a roadside clover patch but at a completely different phenological position and habitat context. Tracking spring and fall individual visits to flowering native trees alongside summer clover patch observations at the same general sites builds a full seasonal picture of the eastern tailed-blue's habitat use across the warm season. That picture, at specific locations across the 26 parishes, fills a documentation gap that summer-only clover observations do not address. Documentation at the Clover Patch Eastern tailed-blue records from North Louisiana appear in citizen science databases but with less coverage than the species' actual abundance warrants, for the same reason that Carolina satyrs are underrecorded: observers focused on large, conspicuous species at flowers do not routinely document the small fast blue at the clover patch on the road shoulder. A deliberate effort to photograph and submit eastern tailed-blue observations from roadside clover patches throughout the 26 parishes contributes to a regional distribution and phenology record that the database currently underpopulates. For documentation: a photograph showing the underside with the hindwing spot pattern and the tail bases, where the orange-capped spots sit, confirms identification definitively. The hindwing-rubbing motion, if captured in a photo sequence showing both wing positions, documents the behavioral field mark that distinguishes the species from other small blues at the same site. October and November records from late-season clover patches in the northern parishes document the end of the tailed-blue season in the upper 26 parishes. March records from early-blooming native plums and viburnums in the southern parishes document the beginning. Both ends of the seasonal window receive less documentation than July and August, when the species peaks in abundance. All of it matters to the regional record. Three Small Blues at One Mud Puddle The productive clay puddle at a North Louisiana road shoulder in July may hold summer azures, eastern tailed-blues, and occasionally gray hairstreaks simultaneously. Those three species represent the core of North Louisiana's small blue community in open habitats, and a mud puddle aggregation provides a comparison opportunity unavailable at flower patches where each species works independently. At the puddle: eastern tailed-blues measure smaller on average than summer azures, show the hindwing tails, and carry orange-capped spots at the tail base. Summer azures measure slightly larger, lack tails entirely, and show smaller faint spots without orange capping on the underside. Gray hairstreaks, the third species in this guild, show gray rather than blue-white undersides with a single prominent orange-and-black eyespot near the hindwing margin rather than the row of small spots the azure and tailed-blue carry. All three species at the same clay puddle, sorted by size, tail presence, and eyespot pattern, calibrates the observer to the small blue community in under five minutes. The puddle does not move. The species return to it throughout the morning. The calibration holds for every subsequent encounter with any of the three species at any site across the 26 parishes for the rest of the season. Clover as Conservation Infrastructure The presence of clover in North Louisiana's roadside margins and lawn edges throughout all 26 parishes represents, from the eastern tailed-blue's perspective, conservation infrastructure built by coincidence rather than plan. European settlers brought clover for forage and hay production. Clover escaped cultivation and naturalized in disturbed soil throughout the region. The eastern tailed-blue, which had been using native legumes in the region since before European settlement, added clover to its host plant list and expanded its abundance in proportion to the clover's expansion. That historical pattern of expansion on an introduced host plant does not diminish the current conservation value of maintaining clover in the landscape. The tailed-blue population that now depends partly on roadside and lawn clover throughout the 26 parishes represents a real butterfly population using a real resource that real management decisions affect. Mowing the clover in bloom eliminates host plant and nectar resource simultaneously. Leaving it standing supports breeding and fueling. Neither outcome qualifies as dramatic conservation action. But across 26 parishes and thousands of miles of roadside clover margins, the cumulative effect of mowing schedules on the eastern tailed-blue population adds up. The species handles the outcome of those management decisions across the region without needing anyone to notice. The clover either blooms or it does not. The tailed-blue finds what blooms. In North Louisiana, enough clover blooms in enough roadsides in enough parishes through enough of the season that the species maintains itself across the region without visible difficulty. The tailed-blue has managed that for long enough that the record of it predates the clovers it now partly relies on. The Smallest Blue at the Biggest Scale Operating at the smallest size of any regularly encountered butterfly in North Louisiana's open habitats, but the scale of its presence across the 26-parish region matches or exceeds most larger species. Breeding at every roadside clover patch, nectaring at every flowering legume from March through November, mud-puddling at every productive damp clay site in the region: the cumulative activity of the eastern tailed-blue population across North Louisiana on any July morning adds up to one of the more substantial butterfly presences in the region even as each individual weighs a fraction of a gram and spans barely an inch. Scale matters in two directions. At the individual level, the tailed-blue gives the observer a butterfly that lands on clover within arm's reach and performs its hindwing-waving dance in full view at a distance manageable without optics. At the population level, the tailed-blue gives the region one of its more consistently abundant open-habitat butterfly species, present at more sites, on more days, across more months than most other North Louisiana butterflies combined. Both scales are real. The half-inch butterfly at the clover patch and the thousands of half-inch butterflies spread across the clover patches of 26 parishes belong to the same species and the same biological fact: Cupido comyntas found North Louisiana's legume-rich open habitats and did not leave. It has operated at both scales simultaneously, individual and population, since before the current clover landscape existed. It will continue after whatever comes next. One More Thing About the Tails The tails on the eastern tailed-blue hindwing grow back after being lost to a predator strike, but only if the butterfly molts, which it does not, as butterflies do not shed and regrow adult wing scales. A tailed-blue that loses both tails carries truncated hindwings for the rest of its adult life. That adult still breeds, still nectars at clover, still mud-puddles at the clay road shoulder. The tails served their purpose: the bird struck the wrong end, the butterfly flew away, the false head accomplished what it was positioned to accomplish. Finding eastern tailed-blues with damaged or missing tails in North Louisiana field observations represents the predation system working as designed. The tail loss means the deception succeeded. The butterfly survived, functional, without its tail. The bird has a piece of wing and no butterfly. The tails grow paper-thin. They wear and fray in old individuals. A fresh eastern tailed-blue in May, tails intact and edges clean, blue scales unscaled, shows the species at its most complete. A worn late-season individual in October, tails frayed or gone, edges ragged: the same species at the end of its individual life span, still breeding if female, still defending territory if male, still finding the clover patch without any difficulty. Both versions belong to North Louisiana's 26 parishes from March through November. Both belong to every open roadside in the region where the clover blooms. Accessibility Hindwing-rubbing motion of resting eastern tailed-blues, the slow backward-and-forward wing movement that makes the tails wave, locates perched individuals at clover patches without visual detection of the closed-wing camouflaged butterfly itself. At mud-puddling sites, the small flicker of movement at the surface of a clay puddle in sun locates aggregations before individual butterflies resolve at distance. Any clover bloom in open sun at a roadside or lawn edge throughout the 26 parishes from March through November. The species finds the clover. The observer finds the species by finding the clover and approaching slowly. The whole chain has no difficult steps. More Information Resources: the North American Butterfly Association at naba.org maintains Louisiana identification resources. iNaturalist accepts eastern tailed-blue observations from all 26 North Louisiana parishes with expert Lepidoptera review. Butterflies and Moths of North America at butterfliesandmoths.org carries Louisiana range data. At the clover patch in July: less than an inch across, iridescent blue in the male, tails waving at the wrong end, orange eyespots positioned precisely to catch a predator's strike at the expendable margin. All of that in a butterfly that most observers mistake for a moth and most lawns support without anyone having planned for it. Clover grew in the disturbed soil. The butterfly found the clover. Neither party consulted anyone. North Louisiana has all 26 parishes of that arrangement running simultaneously from March through November, and the tailed-blue manages it without any help. Where the clover blooms. Which in North Louisiana means all 26 parishes for nine months of every year. Both versions of the tailed-blue, fresh and worn, tailed and tailless, spring and fall, belong to every clover patch in North Louisiana's 26 parishes from March through November. The species does not hold back for optimal conditions. It appears at the clover when the clover blooms, at the mud when the mud dampens, at the woodland edge when the native plum flowers in February. Every warm day of the North Louisiana year that permits flight, the tailed-blue uses it. The clover does not have to be perfect. The mud does not have to be deep. The butterfly finds what the landscape offers and works with it. In the 26 parishes, the landscape offers nine months of workable conditions and the butterfly has never needed more than that. That has always been enough. Still enough. Every warm day. Every clover patch. Every one of the 26 parishes. March to November, no exceptions, no advance notice required from anyone. The tailed-blue does not check the calendar. It checks the clover. In North Louisiana, the clover and the tailed-blue held that arrangement since considerably before either of them had a name in English. Which predates all 26 of them. By a considerable margin.

Accessibility

Hindwing-rubbing motion of resting eastern tailed-blues, the slow backward-and-forward wing movement that makes the tails wave, locates perched individuals at clover patches without visual detection of the closed-wing camouflaged butterfly itself. At mud-puddling sites, the small flicker of movement at the surface of a clay puddle in sun locates aggregations before individual butterflies resolve at distance.

Any clover bloom in open sun at a roadside or lawn edge throughout the 26 parishes from March through November. The species finds the clover. The observer finds the species by finding the clover and approaching slowly. The whole chain has no difficult steps.