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Meet Wahydra graslieae, a mysterious new skipper butterfly from the Ecuadorian Andes

by Andrew D. Warren

Most people don’t notice skipper butterflies. There are a few large, brightly marked skippers that people do sometimes see, but the great majority of skippers are small to tiny, orange, brown or black, and they generally fly very, very fast. When skippers do get noticed, they are often dismissed as ‘moths’.

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Four skipper butterflies showing variation in shape and color. Top left = Urbanus proteus from Florida; top right = Pythonides herennius lusorius from Brazil; bottom left = Amblyscirtes aesculapius from Florida; botrom right = Euphyes berryi from Florida.

Yet there are a few dedicated folks out there who go out of their way to notice skippers. Harold Greeney is one of them. Harold is the owner of the Yanayacu Biological Station in Cosanga, Ecuador, situated on the eastern slopes of the Ecuadorian Andes, which is a very good place if you like skippers. Harold has encountered many unique skippers over the years in the tropical forests near his station, some of which have proven to be new species to science.

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Artines steinhauseri was named as a new species in 2015 from 5 specimens from Ecuador. One of them, shown above, was photographed alive by Harold Greeney.

Harold found an extraordinarily unique skipper on 17 June, 2004, along the Cosanga River east of the Yanayacu Biological Station. It is brown above and mostly rust-colored below, with a unusual pattern of metallic bands and spots on the ventral hindwing.  This small skipper, which I immediately recognized as unique once Harold passed it my way, evaded careful study until June, 2016, when my colleagues and fellow skipper aficionados Eduardo Carneiro and Diego Dolibaina, from Brazil’s Federal University of Paraná, visited me to geek out over skippers for a week. None of us could place Harold’s unique skipper to genus based on its wing markings alone, so Eduardo dissected the genitalia (this is standard practice in such instances). Upon seeing the general form of the genitalia, it was immediately clear that this unusual skipper represented a species of Wahydra, and there were no known species of Wahydra that look much like this one!

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Upperside (left) and underside (right) of the unique male specimen of Wahydra graslieae.

Wahydra are small skippers, grading from orange to dark brown, which inhabit the Andes Mountains of South America from Venezuela to Argentina. They are very rarely encountered in nature, since they fly only in warm or sunny weather yet they inhabit high-elevation habitats where cool, cloudy weather conditions are the norm. The genus Wahydra was named in 1991 by Stephen Steinhauser, and is a meaningless anagram of the name (Kenneth John) Hawyard, a prominent skipper researcher who was based in Argentina and first suggested that a new genus was required for the species now placed in Wahydra. In 1991, nine species were included in Wahydra, and five new Wahydra species have been described since. There are undoubtedly additional Wahydra species yet to be discovered in poorly studied parts of the Andes.

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Specimens of Wahydra vola, and their associated data labels, as figured on the Butterflies of America website. Most Wahydra species are similar to W. vola in size, shape, and coloration.

The evening we determined that this spectacular skipper is a new species of Wahydra, Eduardo, Diego and I happened to be watching episodes of The Brain Scoop, starting with “What is a Species”, and followed by “The Taxonomy of Candy”. Upon browsing the whole list of Brain Scoop videos, we were so impressed by how many of them promote the importance natural history collections, that the idea to name this new Wahydra for Emily Graslie was born. Today, with the publication of the original description of Wahydra graslieae, the fifteenth known species of Wahydra is unveiled.

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Many questions remain about Wahydra graslieae. What does the female look like? What’s its overall distribution? What are the caterpillar foodplants? What do adults feed on? How does it relate to other species of Wahydra? We’re going to need a lot more people paying careful attention to skippers in Ecuador, along with a good bit of luck, before we can have answers to these questions.

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So Much Science in One Photo!

If I could share only one photo with you from my recent expedition across Paraná, Brazil, it would be this one:

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Male Orses cynisca feeding at saliva-soaked tissue paper. Iguaçu National Park, Paraná, Brazil. 31-I-2016. Photo by Andrew D. Warren.

There is so much science in this one photo!

First, this photo is of a skipper butterfly (family Hesperiidae), the group I have spent much of the past 20+ years researching (see my publications).  There are over 4000 species of skippers worldwide, although the greatest diversity of skipper species, by far, is in the New World tropics.

Second, this skipper, Orses cynisca, belongs to a group of skippers whose phylogenetic placement remains unclear- this genus and its relatives (Perichares, Lycas, Alera, etc.) may be more closely related to various Old World skippers than they are to any New World groups.

Third, this skipper has an extraordinarily long proboscis (straw-like ‘tongue’), indicating that it normally feeds at deep-tubed flowers.  Skippers such as this aren’t thought to be good pollinators; rather, they are nectar thieves (explained here)!

Fourth, this skipper is feeding at saliva-soaked tissue paper.  Attracting skippers (and other butterflies) this way is called the “Ahrenholz technique”. The tissue paper mimics bird poop, and the saliva is full of sodium and other nutrients that the butterflies seem to really like! The Ahrenholz technique works best around swarms of army ants (Eciton burchelli and Labidus praedator), which are followed by ‘ant birds’ that generate plenty of real bird poop (= skipper food), as they feast on the many insects fleeing from advancing army ant swarms. The main paper describing this phenomenon is here.

Fifth, the red eyes of this skipper are typical of species that are crepuscular. Crepuscular skippers tend to fly mainly at dawn and dusk, and on cloudy days with low light levels. When little or no biological information is known about a skipper, red eyes usually indicate that it is crepuscular.

Finally, the skipper’s posture and combination of colors resulted in a really beautiful photo- one of those rare pics that I knew would be awesome as soon as the shutter clicked.


Sometimes it takes 22 years to identify and classify a skipper butterfly!


Even though it happened over twenty-two years ago, I remember finding the butterfly like it was only yesterday. Unlike most skipper butterflies in the understory of the Brazilian rainforest, which dart off- out of sight- upon being disturbed, this skipper flew just a few meters and settled along the side of the trail, on the underside of a leaf. As I slowly and quietly approached, I noticed its distinctive rusty coloration and tiny metallic grayish spots on the underside of the hindwings. Little did I know how long the journey ahead would be- the quest to determine what I had just found…


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The unique ‘rusty skipper’ found in August, 1993, in Rondonia, Brazil

This was my first trip to South America, which hosts the world’s richest fauna of skipper butterflies. I chose the Fazenda Rancho Grande in Brazil’s Rôndonia State, since it was the site of a long-running inventory of butterfly species, led by George Austin and Tom Emmel. Researchers had been studying this site for many years by the time I arrived in 1993, and an extensive list of species had already been accumulated. As a nineteen-year-old self-declared skipper nut, my excitement level was over-the-top every day of the two-week expedition, as I encountered skippers I had long dreamed of finding.


Each evening George would review the specimens we caught, making determinations when possible and taking notes on new species for the study area. When George saw my rusty skipper, he took a second and third look, and said he didn’t know offhand what it was- he asked me to send it to him after it was spread for closer study. I didn’t think much more about it during the rest of the trip.


As promised, a few weeks after returning home from the expedition, and after spreading some of the more unusual specimens, I sent the rusty skipper, together with a few other specimens for determination, to George. After a week or so, George replied that the rusty skipper “is new”, but he did not elaborate. I suspected that George had many specimens of this species and was planning to name it in one of his upcoming papers. It was exciting to think that a specimen from my first trip to South America would be important for George’s research!


Then the years passed. George and I collaborated on many skipper papers, describing various new species and genera together, but the rusty skipper never came up in our letters back and forth; while neither of us had forgotten about it, it just never reached the front burner; or perhaps, George wasn’t quite sure where he had put it?


In 2006, I arrived at the McGuire Center for Lepidoptera and Biodiversity as a postdoc, where George had been working as the Senior Collections Manager since the Center opened in 2004. Finally working together under the same roof, we cranked out several papers between then and George’s untimely passing in June, 2009. Being George’s closest collaborator at the McGuire Center, it was left to me to clean out his office and make sense of his research specimens after his passing. During the process of organizing and labeling George’s specimens, late one November afternoon, I found my rusty skipper!


As it turns out, George never accumulated any other examples of this skipper. After dozens of trips to Rôndonia, and after reviewing thousands of skipper specimens collected by many dozens of researchers who visited the site, no additional specimens of the rusty skipper ever surfaced. Sixteen years had passed yet no other specimens had been found- from anywhere!


At about the same time in 2009, a skipper researcher from the Smithsonian Institution published a paper on the genus Telles, which he placed into synonymy with the genus Thracides. One species of Telles, however, the rare Telles pyrex, did not follow the other Telles species into Thracides, and was left hanging in nomenclatural limbo, “incertae sedis”, without any genus-level association. At the time, pyrex was known from just two female specimens, complicating efforts to find a genus-level home for it. Without knowledge of the male anatomy, it was nearly impossible to determine which skippers it may be closely related to.


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The third known female specimen of Telles pyrex, found by George Austin in Rondonia, Brazil, July, 1994

I found a third female specimen of pyrex among George’s study specimens from Rôndonia, which George had not determined to species. While larger than my rusty skipper, and with different forewing markings, and a mostly bright yellowish ventral hindwing, elements of the forewing spot pattern, and the rusty ventral forewing coloration, suggested that my rusty skipper just might be the male of pyrex. If so, pyrex would be sexually dimorphic- with considerably different looking males and females.


During late 2013, my Brazilian colleague Diego Dolibaina spent several months researching skippers at the McGuire Center. At the time I presented him with the female pyrex and the male rusty skipper, and proposed the hypothesis that they might be male and female of the same species. He studied the anatomy, external and internal, of both specimens, and agreed that they likely were conspecific. But we couldn’t be 100% sure from anatomical studies alone.


So in 2014, we removed a single leg from each specimen- the female pyrex and the male rusty skipper- for DNA extraction and sequencing. By studying the “barcode segment” of the COI gene, we were finally able to confirm not only that the rusty skipper is indeed the male of pyrex, but also that pyrex required a new genus name!


So after 22 years, here it is- the description of a new genus- Pseudorphe– for pyrex, along with the first description of its male. To date, this male pyrex– my rusty skipper from 1993- remains the only known male of the species!

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Male (A-B) and female (C-D) of Pseudorphe, the new genus name for pyrex, an extremely rare Amazonian skipper butterfly



Meet Cogia buena, the Good Cogia

In the late 1950’s, Lepidopterist William Harry Evans revised the New World fauna of skipper butterflies (Evans 1951, 1952, 1953, 1955), based on specimens in the British Museum of Natural History (now The Natural History Museum), in London.  In his third volume (1953), Evans reviewed the genus Cogia– with twelve species known at the time, including a new species from Guatemala.  As Evans frequently did when naming new skipper species and subspecies (he named hundreds of them), he used the locality name of the type specimens as a basis for the name of his new species from Guatemala, resulting in… Cogia mala.

Holotype male of Cogia mala, upperside (3) and underside (4), from Guatemala. Photos by Nick Grishin

Holotype male of Cogia mala, upperside (3) and underside (4), from Guatemala. Photos by Nick Grishin.

I don’t know if Evans understood Spanish, but if he did, he must not have liked Cogia mala very much.  In Spanish, “mala” means “bad”- so his new species in its home country became the “bad Cogia.” “Cogia” has a variety of potential meanings across Spanish-speaking countries (and some of them, combined with mala, would likely be considered inappropriate and/or offensive).

I’ve always felt a bit bad for Cogia mala; it is a fine little skipper, and I’ve failed to detect anything “bad” about it, other than, perhaps, its highly restricted distribution (known only from Guatemala) and rarity in collections.  There is no way to change the name Evans gave it, thanks to the rules of the International Code of Zoological Nomenclature.  However…..

Upon recognizing a new species of Cogia in Mexico a few years ago, which appears to be the closest known relative of Cogia mala, I saw a unique opportunity to do something about the “bad Cogia” situation…

Holotype male of Cogia buena, upperside (1) and underside (2), from Oaxaca, Mexico.

Holotype male of Cogia buena, upperside (1) and underside (2), from Oaxaca, Mexico. Photos by Andrew D. Warren.

Meet Cogia buena, the “Good Cogia”! This species was recently described from Oaxaca, Mexico (Warren et al. 2015).  Most taxonomists, when possible, like to have fun with names, so we jumped at the opportunity to do something good for the genus Cogia.

Cogia buena is thus far known only from the southern Mexican state of Oaxaca.  The Good Cogia could have been named several years ago, after the first known males confirmed it represented a new species, but we were waiting, hoping to find female specimens.  However, years passed and no females turned up in collected material, so we’ve named Cogia buena from a series of 44 males.  It will be good when the female is finally found and described, so we may better understand the relationship of Cogia buena to C. mala and other related species.

A more detailed study of the genus Cogia is currently in progress by Warren and collaborators.

Live male of Cogia buena from Oaxaca, Mexico. Photo by John Kemner.

Live male of Cogia buena from Oaxaca, Mexico. Photo by John Kemner.

Type locality of Cogia buena in the Sierra Madre del Sur of Oaxaca, Mexico, June, 2008.

View from near the type locality of Cogia buena, in the Sierra Madre del Sur of Oaxaca, Mexico, June, 2008.

Literature Cited:

Evans, W. H. 1951. A Catalogue of the American Hesperiidae Indicating the Classification and Nomenclature Adopted in the British Museum (Natural History). Part I. Introduction and Pyrrhopyginae. London, British Museum (Natural History): x + 92 pp., pls. 1-9.

Evans, W. H. 1952. A Catalogue of the American Hesperiidae Indicating the Classification and Nomenclature Adopted in the British Museum (Natural History). Part II. Pyrginae, Section I. London, British Museum (Natural History): vi + 178 pp., pls. 10-25.

Evans, W. H. 1953. A Catalogue of the American Hesperiidae Indicating the Classification and Nomenclature Adopted in the British Museum (Natural History). Part III. Pyrginae, Section II. London, British Museum (Natural History): vi + 246 pp., pls. 26-53.

Evans, W. H. 1955. A Catalogue of the American Hesperiidae Indicating the Classification and Nomenclature Adopted in the British Museum (Natural History). Part IV. Hesperiinae and Megathyminae. London, British Museum (Natural History): vi + 499 pp., pls. 54-88.

Warren, A. D., D. R. Dolibaina & C. Hernández-Mejía. 2015. A new species of Cogia from Oaxaca, Mexico (Lepidoptera: Hesperiidae: Eudaminae). Zootaxa 3941(2):239-246.

My Top 20 Arthropod Photos From 2013

Some of my favorite nature photographers have been sharing their best or favorite wildlife photos from 2013 over the past couple of days, so I decided to get in on the fun!  There was no way I could trim my list down to 10 photos, and it was a challenge limiting it to 20, but here they are, my 20 favorite arthropod photos from 2013, in roughly chronological order!

Mating pair of Cicindela scutellaris unicolor, USA, Florida, near Bronson, date

Mating pair of Festive Tiger Beetles (Cicindela scutellaris unicolor), FLORIDA: Levy Co.:, near Bronson, 13-IV-2013

In April, I spent several weekends in the sandhill habitats of Levy County, Florida, paying special attention to Florida’s subspecies of one of my long-time favorite tiger beetles, the Festive Tiger Beetle (Cicindela scutellatis unicolor).  On two different mornings I was lucky enough to find mating pairs of these beetles, which allowed me to get closer than tiger beetles normally do!

Posterior views of 12 different Promethea Moth larvae, June, 2013

Posterior views of 12 different Promethea Moth larvae (Callosamia promethea), reared in Gainesville, FLORIDA, June, 2013

In May and June, I had the pleasure of rearing Promethea Moths (Callosamia promethea).  While the adults of this moth are spectacular, the larvae are over-the-top cool, with a distinct smiley face on the butts of later instars!  Each one has its own unique personality…

Robber Fly and Wasp

Robber Fly (Proctacanthus sp.) feasting on a Western Yellowjacket wasp (Vespula pensylvanica), COLORADO: Douglas Co.: Hidden Pointe area, 6400′, 14-VII-2013

On my first day in the field this summer in Colorado, I was fortunate enough to watch a large robber fly (Proctacanthus sp.) take out a flying Western Yellowjacket wasp (Vespula pensylvanica), and was able to move in for photos!  Apparently, the yellowjacket is completely defenseless when attacked by these mighty robber flies, as I witnessed similar attacks on subsequent days.

male Lustrous Copper (Lycaena cupreus snowi)

male Lustrous Copper (Lycaena cupreus snowi) perching at the base of a talus slope, COLORADO: Clear Creek Co., Loveland Pass, 12,200′, 16-VII-2013

I’ve always been interested in the high-altitude butterfly fauna of the Rocky Mountains, and was fortunate to encounter good weather above treeline on several days in July.  Early on July 16th, I found this male Lustrous Copper (Lycaena cupreus snowi) before he really warmed up, and was able to get closer than I ever have to this magnificent species.

Female Saltmarsh Skipper (Panoquina panoquin)

Female Salt Marsh Skipper (Panoquina panoquin) feeding at Spanish Needles (Bidens alba), FLORIDA: Levy Co., near Cedar Key, 12-X-2013

In October, I got a new camera (Canon 70D with 100mm macro lens), and I basically haven’t set it down since (all remaining photos were taken with this camera)!  This photo of a female Salt Marsh Skipper (Panoquina panoquin) was one of the first photos taken with the new setup, and remains one of my favorite to date.

Robber Fly

My new favorite robber fly, the Florida Bee Killer (Mallophora bomboides), FLORIDA: Levy Co., 12-X-2013

This gigantic robber fly, the Florida Bee Killer (Mallophora bomboides), is a fantastic critter to photograph, as it sits motionless for extended periods of time.  Not to mention the incredible color pattern, the beautifully textured tufts of bristles, and those eyes!

Male Little Metalmark (Calephelis virginiensis)

Male Little Metalmark (Calephelis virginiensis), FLORIDA: Levy Co., 12-X-2013

The Little Metalmark (Calephelis virginiensis) is the only member of the family Riodinidae in Florida, and is also one of the smallest of metalmarks!  This tiny male was perching atop a yellow flower, waiting for passing females.

Male Palatka Skipper (Euphyes pilatka) feeding at Pickerelweed

Male Palatka Skipper (Euphyes pilatka) feeding at Pickerelweed (Pontederia cordata), FLORIDA: Levy Co., 12-X-2013

The Palatka Skipper (Euphyes pilatka) is the largest member of its genus, restricted to the southeastern USA.  It is especially fond of Pickerelweed (Pontederia cordata) flowers, as shown above, and adults may spend many minutes on a cluster of these extraordinary flowers.  The only downside is you pretty much always have to go wading, up to knee-deep, to get close to the blooms.

Fully-grown larva of the Polyphemus Moth (Antheraea polyphemus)

Fully-grown larva of the Polyphemus Moth (Antheraea polyphemus), FLORIDA: Marion Co., W of Ocala, 25-X-2013

While widespread and common across much of North America, the Polyphemus Moth (Antheraea polyphemus) is a truly spectacular animal, and in my opinion, the larva is one of the most beautiful objects in all of nature.  I was lucky enough to encounter a good number of these during fieldwork in Florida in 2013.


Male Wingless Florida Grasshopper (Aptenopedes aptera), FLORIDA: Marion Co.: W of Ocala, 25-X-2013

Grasshoppers demanded a lot of my attention in 2013, as I attempted to learn as many species of Florida hoppers as I could.  Shortly after I started my new blog, I posted a list of Florida’s grasshopper species, with photos of many species, and have updated this post periodically as I’ve obtained new photos.  This photo of a male Wingless Florida Grasshopper (Aptenopedes aptera) is my most colorful grasshopper photo of the year.


Fully-grown Skiff Moth larva, Prolimacodes badia (Limacodidae) on a Turkey Oak leaf (Quercus laevis), FLORIDA: Marion Co.: W of Ocala, 25-X-2013

The larva of the Skiff Moth (Prolimacodes badia) is one of the most unusual of all caterpillars! In fact, it doesn’t resemble a caterpillar much at all!  Its head, to the right, is tucked underneath the rest of its body, and it remains motionless for long periods of time.  Its legs are highly modified, gelatinous-looking blobs that move in a wavelike motion.  Thus, when walking, the caterpillars appear quite slug-like.

robber fly

Perching Diogmites salutans, awaiting passing prey, FLORIDA: Levy Co.: near Bronson, 26-X-2013

I really love photographing robber flies, and this particular individual of Diogmites salutans perched for me for several minutes.  As I was looking through the view finder, I enjoyed watching this fly swivel its head around as it tracked passing insects, potential prey items.  With such a skinny neck, the head is able to move in ways I could have never imagined!

Wagneriana tauricornis

How many faces do you see on this spider? Wagneriana tauricornis, FLORIDA: Levy Co.: near Bronson, 26-XI-2013

When I first stumbled across this spider, Wagneriana tauricornis, I wasn’t sure what I was looking at!  From a distance, it looked like a bit of detritus or bird poop.  But after identifying it as a spider and taking a few photos, I was amazed at all the faces I saw on this spider!  It was the subject of my first blog post!

Harvester (Feniseca tarquinius)

Perching male Harvester (Feniseca tarquinius) awaits passing females, FLORIDA: Alachua Co.: Gainesville, UF campus at NATL, 31-X-2013

For the past two years, I’ve been studying the population of Harvester butterflies (Feniseca tarquinius) at the Natural Area Teaching Laboratory (NATL) on the University of Florida Campus in Gainesville.  While it is easy to find and photograph larvae and even pupae, adult Harvesters are a real challenge to photograph!  Finally, on Halloween, I succeeded in getting photos of a perching male- the last bit I needed to complete a blog post on this fascinating insect, America’s only carnivorous butterfly!

Rosemary Grasshoppers (Schistocerca ceratiola)

Mating pair of Rosemary Grasshoppers (Schistocerca ceratiola) perched on Florida Rosemary (Ceratiola ericoides), FLORIDA: Levy Co., near Bronson, 11-XI-2013

Ever since “getting back into” grasshoppers, I’ve been looking for the Rosemary Grasshopper (Schistocerca ceratiola).  It is a large grasshopper, entirely restricted to Florida, living only in habitats where Florida Rosemary (Ceratiola ericoides) grows.  Unlike most grasshoppers that are general herbivores, the Rosemary Grasshopper feeds only on Florida Rosemary!  Finally, in November, I succeeded in finding several of these reclusive grasshoppers, and dedicated not just one, but two blog posts to this awesome species.

Wolf Spider (Hogna sp.) eating a Festive Tiger Beetle (Cicindela scutellaris unicolor), FLORIDA: Levy Co.: Bronson, 24-XI-2013

Wolf Spider (Hogna sp.) eating a Festive Tiger Beetle (Cicindela scutellaris unicolor), FLORIDA: Levy Co.: Bronson, 24-XI-2013

Anyone who has tried to catch or photograph tiger beetles knows how wary and fast they are, how difficult they are to sneak up on!  That’s why I was astonished to find this large wolf spider (Hogna sp.) feasting upon a Festive Tiger Beetle (Cicindela scutellaris unicolor)!  How this spider was able to catch the beetle remains a mystery, but I can’t imagine it happens very often!

Mycotrupes gaigei with phoretic fly

Endemic Florida beetle Mycotrupes gaigei with phoretic sphaerocerid fly Cecroptera longicauda riding on its left foreleg, FLORIDA: Levy Co.: near Bronson, 28-XI-2013

Thanksgiving Day marked the beginning of “cool winter beetle” season in Florida, with the appearance of Mycotrupes gaigei, a flightless geotrupid endemic to peninsular Florida.  As detailed in this blog post by Phil Torres, a phoretic sphaerocerid fly, Cecroptera longicauda (shown above on the left foreleg of the beetle), can often be found riding around on these beetles.

Mating pair of Brephidium pseudofea, FLORIDA: Levy Co.: Hwy. 24, N end of bridge to Haven's Island, 8-XII-2013

Mating pair of Eastern Pygmy-Blues (Brephidium pseudofea), FLORIDA: Levy Co.: Hwy. 24, N end of bridge to Haven’s Island, 8-XII-2013

I spent my last day in the field in Florida for 2013 with the smallest butterfly in eastern North America, the Eastern Pygmy-Blue (Brephidium pseudofea).  Over the course of a couple hours, I was able to observe and photo-document the lives of these little gems, and was lucky enough to watch the courtship and mating of the pair shown above!

Polyxenus millipedes under a rock near Hidden Pointe, 6400', NNW of Castle Rock, Douglas County, Colorado, 18-XII-2013

Polyxenus millipedes under a rock near Hidden Pointe, 6400′, NNW of Castle Rock, Douglas County, COLORADO, 18-XII-2013

Upon arriving in Colorado for holiday break, I was astonished to find unseasonably warm conditions awaiting me!  On my first bug hunt, I found masses of unfamiliar arthropods under rocks, that at first I failed to identify!  As explained in this post, these little critters are some amazing little millipedes, in the genus Polyxenus, and they are protected by a unique mechanical weapon!

Female Dainty Sulphur (Nathalis iole), basking in Colorado's late December sunshine, CO: Douglas Co.,: Hidden Pointe area, ca. 8 mi NNW Castle Rock, 6400', 18-XII-2013

Male Dainty Sulphur (Nathalis iole), basking in Colorado’s late December sunshine, COLORADO: Douglas Co.,: Hidden Pointe area, ca. 8 mi NNW Castle Rock, 6400′, 18-XII-2013

The year ended with a surprise, on an unseasonably warm December day in Colorado!  Just before mid-day on December 18th, I scared up this male Dainty Sulphur (Nathalis iole), which was the latest a non-overwintering adult butterfly has ever been found in Colorado!  It was a beautiful insect to end the year with, and a significant record as as well.

I hope you’ve enjoyed my favorite photos from 2013!  Happy New Year!

Gregarious Overwintering Masses Of Millipedes Are Protected By A Mechanical Weapon!

Every day in the field provides opportunities to learn something new, and this past Tuesday was no exception!  Thrilled to be back in Colorado, and surprised to have encountered such warm weather in December (it reached 62 degrees F), I wasted no time getting out into nature, at a site I’ve been surveying since 1998.  There were still scattered patches of snow on the ground, but most of the landscape was dry and navigable, overlooked by the majestic Rocky Mountains of the Colorado Front Range.

View to the west, Hidden Pointe area, 6400', NNW of Castle Rock, Douglas County, Colorado, 18-XII-2013

View to the west, Hidden Pointe area, 6400′, NNW of Castle Rock, Douglas County, Colorado, 17-XII-2013

Entomologists are always looking under rocks and fallen wood, and over the years, I’ve learned which are the “best” rocks at the site for finding cool invertebrates.  This set of rocks, at the base of a large wooden pole, have traditionally been some of the most productive rocks here.

These rocks, along the ridge near Hidden Pointe, almost always provide some neat arthropod surprises, no matter the season!

These rocks, along the ridge near Hidden Pointe, almost always provide some neat arthropod surprises, no matter the season!

As I flipped the first rock, I was amazed at what I saw!  Hundreds, if not thousands of tiny, fuzzy, worm-like minibeasts!  I had never seen these critters before, and had no idea what I was looking at.  Their size, and the way they moved, reminded me of dermestid larvae (carpet beetles), but the whitish tufts on their posterior ends seemed a bit off.  I proceeded to photograph the mass of fuzzy little creatures, and was astonished to find similar masses under three additional rocks!

Polyxenus millipedes under a rock near Hidden Pointe, 6400', NNW of Castle Rock, Douglas County, Colorado, 18-XII-2013

Polyxenus millipedes under a rock near Hidden Pointe, 6400′, NNW of Castle Rock, Douglas County, Colorado, 17-XII-2013

As soon as I returned home, I emailed the above photo to one of the most knowledgeable entomologists I know, Ted MacRae, who is also one of the world’s top Coleopterists.  If these were dermestid larvae, surely Ted would know.  Ted’s reply, which arrived in just a few minutes, blew me away!  He identified them as millipedes in the family Polyxenidae.  Wow!  I’m sure I would have realized they were not beetle larvae had I put one under the microscope and given it a good look, but I rushed to send off the photo first…  After some subsequent research online, I was able to determine these as members of the genus Polyxenus, probably Polyxenus lagurus.

I’m certainly no millipede expert, but from what I’ve been able to find, polyxenid millipedes are not well known.  What is known about them, however, is pretty amazing!  While most millipedes defend themselves with noxious chemicals, polyxenid millipedes defend themselves with a “mechanical weapon”!  Research by Thomas Eisner and collaborators demonstrated that the whitish tufts on the posterior ends of these millipedes are composed of detachable bristles, which are used to immobilize potential predators, especially ants!

Each bristle includes a barbed shaft, and several hooked prongs at the tip.  When provoked, the millipedes project the tufts towards the attacker, which then detach, and get caught on the mouthparts, antennae, legs and setae of the antagonist.  In the effort to cleanse themselves of bristles, predators such as ants only entangle themselves more thoroughly in the bristles.  The panic-stricken struggle to rid themselves of bristles is usually futile, and the resulting entanglement of bristles can leave the predators completely immobilized, often terminally!  This defense perhaps explains the benefit of overwintering in large, gregarious masses!

The Smallest Butterflies Are Some of The Toughest! Dainty Sulphur (Nathalis iole)

Growing up along Colorado’s Front Range, as a young lepidopterist, the last warm days of the season were always special opportunities, to see how late the toughest butterflies could persist into the shortening and progressively colder days of November.  On a typical year, up to a dozen butterfly species can usually still be found here on warm days in early November, with that number dwindling to nearly or exactly zero by the end of the month.  Adults of only five butterfly species have ever been found in nature in December in Colorado, including the Orange Sulphur Colias eurytheme (late date of 4 December), Clouded Sulphur Colias philodice eriphyle (15 December), Dainty Sulphur Nathalis iole iole (5 December), Painted Lady Vanessa cardui (4 December) and the Mourning Cloak Nymphalis antiopa (31 December).  Of these, only the Mourning Cloak passes the winter here as an adult, though along with other nymphalid butterflies that overwinter as adults, it usually resists the temptation to fly around on warm winter days until late February or early March.  Remaining adults of the other four species will inevitably perish with the onset of winter, but they hang on for as long as they can!

Of all the adult butterflies that have persisted into December in Colorado, all are year-round residents here, except for the Dainty Sulphur.  The tiny Dainty Sulphur cannot survive the long winters in Colorado, and freezes out of the state on an annual basis.  But starting in April each year, these diminutive butterflies begin to arrive, from Texas and the desert southwest, probably due to winds more than their own dispersal abilities, and by the end of the season, they can literally be found everywhere in the state, even on alpine tundra above 13,000′ elevation!  There are several larval foodplants for them here in warm months, and the Dainty Sulphur can produce two or three generations in Colorado before it is finally frozen out at the end of the season.  But the late-season adults come equipped with an unusually dark, greenish ventral coloration, for taking in the early winter rays, and prolonging late-season life.

I arrived back in Colorado for the holidays two days ago, and did not expect the unseasonably warm conditions awaiting me!  It was 62 degrees F yesterday, and it reached 64 today!  Of course, such conditions mandate field work (and postponement of holiday shopping), to see what is still out!  After the recent frigid low of -14 degrees F a couple weeks ago, I did not expect to find many insects, but have been pleasantly surprised!

Today at about 11:00 hrs, on a ridge at 6400′ elevation, I was astonished to scare up a male Dainty Sulphur!  Shortly after taking flight, he settled on a dead plant a few feet away, so I moved in for photos! Here’s the first good shot I got of him:

Female Dainty Sulphur (Nathalis iole), basking in Colorado's late December sunshine, CO: Douglas Co.,: Hidden Pointe area, ca. 8 mi NNW Castle Rock, 6400', 18-XII-2013

Male Dainty Sulphur (Nathalis iole), basking in Colorado’s late December sunshine, CO: Douglas Co.,: Hidden Pointe area, ca. 8 mi NNW Castle Rock, 6400′, 18-XII-2013

I spent the next several minutes getting photos.  In the persistent breeze and warm morning sun, he did not sit still in any one place for long, and most of the time, after taking flight, he would land in places that were not conducive for photography.  But, finally, he landed in a clearing where I could get several crisp photos.  As you can see below, he was in excellent condition, not missing a scale!

Female Dainty Sulphur (Nathalis iole), basking in Colorado's late December sunshine, CO: Douglas Co.,: Hidden Pointe area, ca. 8 mi NNW Castle Rock, 6400', 18-XII-2013

Male Dainty Sulphur (Nathalis iole), basking in Colorado’s late December sunshine, CO: Douglas Co.,: Hidden Pointe area, ca. 8 mi NNW Castle Rock, 6400′, 18-XII-2013

This is the latest a non-overwintering adult butterfly has ever been found in Colorado!  Judging from his immaculate condition, he most likely survived the recent frigid weather as a pupa, and probably eclosed in yesterday’s unseasonable afternoon warmth.  While there is little or no chance of this guy finding a mate or surviving even a week (cold weather predicted to return soon), his appearance today is testament to the toughness of this tiny butterfly!