Standing,
talking to a photographer friend and enjoying the beauty of the first sunny day
all week, a streak of bright blue darted past my eyes. The color was electric,
rivaling the azures of morpho butterflies in the tropics, though this bug was
much smaller. Just past our heads, it landed in a patch of late boneset, where
we had already been enjoying the butterfly diversity. Now all attention was
turned to the new arrival: a Great Purple Hairstreak (Atlides halesus); not a large butterfly, but big for its family,
nearly twice the size of some hairstreaks; most are less than an inch tall.
This particular species is notoriously uncommon in both Arkansas and elsewhere
in its range. One cannot usually go looking for it without failure, they have
to find you…like this one did. The Great Purple Hairstreak lays its eggs on
mistletoe, which the caterpillars feed on. With the abundance of that
particular plant in the Ozark region of Arkansas, one would think the species to
be much more common. But, for some reason they aren’t. In fact, this was the
only one I’ve ever seen.
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| Great Purple Hairstreak (Atlides halesus) in all its glory. |
Hairstreaks form
the diverse subfamily, Theclinae, in the larger family of “gossamerwings”
called Lycaenidae. Taking a step backwards to the overarching family
Lycaenidae, there is an array of similar species that are nearly equally as
enjoyable as the hairstreaks. They have such names that inspire closer
investigation like copper, blue, elfin, and azure; but it would take many more words
to give them a fair chance! So, onward to hairstreaks…
It’s hard to track down the origin of the name “hairstreak”, but it seems to have begun appearing in literature in the early 18th century. One of the first mentions is in Gazophylacii naturae et artis decas prima, written by English apothecary James Petiver, who had a penchant for botany and entomology. In this book, with hand-colored plates, the name “hair-streak” appears several times. However, he never explains the reason behind this name. Many of the hairstreaks have tell-tale black antennae ringed with white bands that could have something to do with the moniker.
My Great Purple Hairstreak was seen at a local restored and mitigated wet prairie site. Calling it amazing is an understatement. In less than ten years of restoration work, the 46-acre site functions largely as it did before it was settled in the 1830s. Both flora and fauna have bounced back, including several rare or unusual species thought lost to the area. In late summer and early fall, the prairie abounds with insect diversity, with an emphasis on the butterflies. It was at this same prairie, three days before the Great Purple Hairstreak, that I found another rarity of the same family: White M Hairstreak (Parrhasius m-album). Whoever decided upon this butterfly’s Latin name should get a pat on the back for creativity. The species name literally means “white ‘m’” (Parrhasius was a famous Greek painter in ancient times). This is another large hairstreak with beautiful blue upper wings, a trait exhibited by several other members of the family. However, in almost all species the color remains hidden. Hairstreaks keep their wings held tightly upright, providing quick flashes of the blue only in flight.
It’s hard to track down the origin of the name “hairstreak”, but it seems to have begun appearing in literature in the early 18th century. One of the first mentions is in Gazophylacii naturae et artis decas prima, written by English apothecary James Petiver, who had a penchant for botany and entomology. In this book, with hand-colored plates, the name “hair-streak” appears several times. However, he never explains the reason behind this name. Many of the hairstreaks have tell-tale black antennae ringed with white bands that could have something to do with the moniker.
My Great Purple Hairstreak was seen at a local restored and mitigated wet prairie site. Calling it amazing is an understatement. In less than ten years of restoration work, the 46-acre site functions largely as it did before it was settled in the 1830s. Both flora and fauna have bounced back, including several rare or unusual species thought lost to the area. In late summer and early fall, the prairie abounds with insect diversity, with an emphasis on the butterflies. It was at this same prairie, three days before the Great Purple Hairstreak, that I found another rarity of the same family: White M Hairstreak (Parrhasius m-album). Whoever decided upon this butterfly’s Latin name should get a pat on the back for creativity. The species name literally means “white ‘m’” (Parrhasius was a famous Greek painter in ancient times). This is another large hairstreak with beautiful blue upper wings, a trait exhibited by several other members of the family. However, in almost all species the color remains hidden. Hairstreaks keep their wings held tightly upright, providing quick flashes of the blue only in flight.
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| White M Hairstreak (Parrhasius m-album) |
Sharing boneset with
these rarities were two other, more common hairstreaks, both fairly numerous on
the property. First, the Gray Hairstreak (Strymon
melinus), perhaps North America’s most widespread hairstreak. Whereas most
butterflies have a select list of particular host plants, the Gray Hairstreak
is known to use a wide variety, lending to it the perfect means for being so
common. Nonetheless, it’s good-looking: frosted grays flecked with orange and
white.
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| Gray Hairstreak (Strymon melinus) |
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| Red-banded Hairstreak (Calycopis cecrops) |
The other
species on this particular prairie is the Red-banded Hairstreak (Calycopis cecrops), a specialty of the
southeastern U.S. Unlike most caterpillars, which feed on living host plants, Red-banded
Hairstreak caterpillars feed on fallen and decaying leaves of sumac and certain
oaks. This is a hairstreak I always look forward to seeing. It flies from April
to October, but I seem to find the largest numbers after a final big hatch in
late summer. More of a bluish-gray, this tiny butterfly sports the namesake
thick orange band, running through both the hind and forewings, accented with
an array of black spots and thinner white bands.
Leaving Arkansas and heading south into the Lower Rio Grande Valley of Texas, the Red-banded Hairstreak is replaced by a look-alike: Dusky Blue Groundstreak (Calycopis isobeon). This hairstreak can be found in thornscrub habitat, accompanied by riparian areas throughout southern Texas. Caterpillars of the Dusky Blue Groundstreak find the decaying plant matter they are looking for here, and grow into a butterfly very closely resembling the Red-banded Hairstreak, which doesn’t exist along the Mexican border of far-south Texas. On occasion, where their ranges meet further north, the two species have been known to interbreed, begging the question of whether or not they are actually two distinct species.
Leaving Arkansas and heading south into the Lower Rio Grande Valley of Texas, the Red-banded Hairstreak is replaced by a look-alike: Dusky Blue Groundstreak (Calycopis isobeon). This hairstreak can be found in thornscrub habitat, accompanied by riparian areas throughout southern Texas. Caterpillars of the Dusky Blue Groundstreak find the decaying plant matter they are looking for here, and grow into a butterfly very closely resembling the Red-banded Hairstreak, which doesn’t exist along the Mexican border of far-south Texas. On occasion, where their ranges meet further north, the two species have been known to interbreed, begging the question of whether or not they are actually two distinct species.
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| Dusky Blue Groundstreak (Calycopis isobeon) |
Pondering too
deeply about such matters and you could miss another hairstreak in this diverse
and underappreciated habitat that dominates south Texas. As usual, a fleeting
glimpse of a quick grayish butterfly almost always leads to a hairstreak. In
the woods along the Rio Grande, one such quick flyby led to a Mallow
Scrub-Hairstreak (Strymon istapa istapa).
Arguably the dullest of the bunch so far, this mostly gray-and-white hairstreak,
with brown upperparts, makes up for looks with its interesting geographic
history. The species is found in two disjunct ranges: one extends from Texas,
across the southwest, and into South America; the other from southern Florida, down
through the West Indies. Some butterflies have a similarly split range, but its
most apparent in my bird-driven world with species like Crested Caracara,
Burrowing Owl, and the scrub-jays, which eventually diverged into several
species because of the separation.
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| Mallow Scrub-Hairstreak (Strymon istapa istapa) |
Mention of the West
Indies brings me to yet another, the Atala Hairstreak (Eumaeus atala). In fact, my preferred hairstreak even after the
Great Purple entered into my life. Like the Great Purple, the Atala is
classified as one of the “large tropical” hairstreaks; not quite as large, but
equally as flashy. Its larvae feed on coontie, a group of plants common in the
Caribbean.
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| Atala Hairstreak (Eumaeus atala) |
In nature, it’s often hard to find a creature that captures the
essence of beauty in its entirety. Of course, the definition of beauty is
relative, but the Atala is the whole package. For starters, the butterfly is a
silky, jet black, something that naturally pleases the human eye. Staring at this
bug is like staring into a black hole. As the sun works its way through a
patchwork of leaves, light hits tiny scales of aquamarine among the black. Like
looking at a field of stars on a moonless night is the Atala. Two
constellations of spots, one on the hind wing and one on the body, stand in
contrast to the bright orange abdomen and orange-red splotch on the lower hind
wing.
Its host plant,
coontie, is a primitive cycad. Several species are found in well-drained, sandy
soils of West Indian islands, often in pine woods. It was in one particularly
dry pine forest on the island of Abaco, in the Bahamas, that I saw nearly 50
Atala; clearly common when coontie is available. The Atala was probably once
common in southern Florida and the Keys, but is now very unpredictable from
year-to-year. The preferred habitat for it and its beloved coontie is degraded
and nearly gone from the Continental U.S. However, there is some comfort in
knowing the species lives on further south.
Deeper into the
tropics appears the genus Arawacus. Though
a recognizable genus, as with many butterflies in the tropics, it is often hard
to identify a species accurately due to lack of study. Arawacus is known for its “zebra striping” in some form or fashion,
some livelier than others. A particularly strongly marked species is the
Togarna Hairstreak (Arawacus togarna).
One of the better known of the genus, this species ranges from southern Mexico
through Belize, where I photographed it, and south into Amazonia. Quite different
from a standard-issue hairstreak, this butterfly took me completely off guard,
as do most things on a naturalist’s first trip to the tropics. Wandering
through a break in the jungle, the Togarna streaked (typical) past my face and
landed on a blade of grass. I was immediately enamored by its thick black,
triangular markings interspersed with creamy lines, all culminating in an
attractive orange spot at the end of the hind wing.
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| Togarna Hairsteak (Arawacus togarna) |
But
of course, you don’t have to travel far to get your own hairstreak fix. Hairstreaks
and their brethren can be enjoyed the world over. There are around 5,500
species in the family Lycaenidae known to exist in almost every corner of the globe,
from backyards to the depths of a remote jungle. Amazingly, nearly half of
these species, as caterpillars, have formed mutualistic relationships with
other insects; most often being tended by ants. “Tended” has a variety of
different meanings, but in most cases, the caterpillar secretes a sugary liquid
that the ants consume. Because of this important resource, the ants keep
constant guard over their caterpillar herd.
The tending can get
pretty extreme. Eastwood & King (1998) studied the relationships of several
ant and hairstreak species on an acacia tree in Australia. One caterpillar, (Arhopala wildei), feeds on the tree,
which is tended by a very aggressive ant (Oecophylla
smaragdina) who enjoys the sap produced by the tree. The ants are ruthless
protectors, yet somehow the caterpillars survive. On the same tree, there’s
another ant (Polyrhachis queenslandica)
that shuts itself away from the aggressive ants in protected shelters during
the day. The A. wildei caterpillars
live in these compounds with the ants and are carried out at night to feed when the aggressive species of ant is
inactive. The benefit to the ants is, as usual, a sugary secretion. On the flip
side of the same story, the aggressive O.
smaragdina ant is associated with its own Lycaenid caterpillar (Liphrya brassolis). However, this
species feeds on the ants, who gain nothing, not even a chance to counterattack
due to the caterpillars’ thick skin. This is a complicated example, but just
awesome!
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| Here's a simpler North American example of an ant waiting for the sweet secretion from a Gray Hairstreak caterpillar. Hobbs State Park, Benton County, AR |
"I believe that there is a subtle magnetism in nature,which if we unconsciously yield to it will direct us aright."--Henry David Thoreau, Excursions, 1863
For further reading: Caterpillars of Eastern North America by David L. Wagner, A Swift Guide to Butterflies of North America by Jeffrey Glassberg, Arkansas Butterflies and Moths by Lori A. Spencer
For further reading: Caterpillars of Eastern North America by David L. Wagner, A Swift Guide to Butterflies of North America by Jeffrey Glassberg, Arkansas Butterflies and Moths by Lori A. Spencer
