I came across this short article today claiming that this recent description of the hairstreak butterfly, Ministrymon janevicroy Glassberg 2013, may in fact be the “last truly distinctive butterfly species left to be discovered in the United States…. [and] the era of new U.S. butterfly species is ending”. I find that statement a little bit odd. One one hand it seems obvious, most of the butterflies in the United States were described long ago. 90% of the hairstreak butterflies were described before 1900 and 97.5% before 2000 (R. Robbins pers. comm.). On the other hand it gives me an itch in the back of my brain that may falsely imply we’ve completed a task and we can move past collecting or research on butterflies. I don’t think the authors intended the latter – and while it’s good to realize we’ve come this far in butterfly taxonomy, it might be helpful to discuss how far we haven’t come (especially when you consider moths!).
The paper itself (free from Zookeys above) is great – it very carefully outlines the case to separate these species and I would easily agree with their conclusions. The closest the authors get to saying this is the last butterfly to be described in the US is here at the end of page 14 and onto page 15.
The Eumaeini fauna of the United States is well-documented, and most species described in the past 75 years have arguably been cryptic species that had been overlooked because of wing pattern similarity with known species. … In sharp contrast, slightly more than 20% of the Central and South American eumaeine fauna is undescribed (Robbins 2004b), but the vast majority of these undescribed species are exceedingly rare in museum collections, unlike M. janevicroy. Assessing variation of these rare species remains an obstacle to documentation.
And as it turns out the lines about the last butterfly were from a press release written by the authors (pers. comm.). But to me it sounds like splitting hairs, are these butterflies really that distinct? New butterflies are still being described from the US from less obvious characters as eye color, but often have large differences in the genitalia – and these characters can often be much more distinctive than a color feature that fades in preserved specimens. So, yes, this is perhaps the last species to be found that could be told apart in the field. But if anything it points at how much we need specimens in collections to figure these things out in the first place. The authors used 88 specimens of M. janevicroy and compared them to hundreds of other specimens of other species. Good thing there are collectors working hard in the field to find as many of these butterflies as possible (and often at the time not knowing exactly what they are catching). As lepidopterists look closer at the differences separating many of our more diminutive species new names are created to describe what was once thought to be one larger, wide-ranging, single species.
And any readers of my blog should well be aware that many, many moth species are left to be described in the United States. I know of a few revisions that are upcoming that are going to nearly double the size of relatively large families of big and well collected moths – not to mention how little progress we’ve made in the microlepidoptera. One estimate I’ve heard suggests that only 20% of the Tortricidae moth species have been described! When intensive revisions are conducted of these smaller groups the species numbers explode.
Go out and collect!
The Hop Azure (Celastrina humulus) is a diminutive and uncommon blue found on the front range of the Rockies here in Colorado. Its host plant is the wild hop: Humulus lupulus, varieties of which are of course a critical ingredient in beer! In a week or two I’ll be out in the field looking to photograph this sucker along with the swallowtail Papilio indra indra, hopefully with some luck.
And so along comes Robert Schorr who has been intimately aware of this butterfly for years and has wished he had funding to work on it. Robert, being an unparalleled genius, combined two of my favorite things: Lepidoptera and beer. A quick presentation to Odell Brewery based out of Fort Collins, Colorado and voila- Celastrina Saison Ale was born. And of course, $1 of each beer sold will go to Schorr’s research on the Hop Azure butterfly. Genius. Perhaps next up, a beer that supports my research on hop-moths? (there are a few of course!) Better yet the hop-growing industry might be interested in that work…
And for the non-beer lovers out there a Saison is a nice and effervescent ale with lots of fruit and spice, but still on the dry end and not very sweet – perfect for drinking on a warm summer day.
The time is fast approaching for this years National Moth Week, July 20-28 2013! The first ever Moth Week last year was a huge success with over 300 events from 49 US States and 30 countries! Help make this year even bigger – if you’re interested in moths at all you should find a local event to attend or create one of your own. Public or private, you can participate with a leisurely night where you crack a few beers with friends and watch some moths – or you can invite the public and encourage photography, collecting, and submission of your data! Every event helps to spread the popularity of moths, even if it’s just you in your back yard.
I’ll be planning a Moth Week event here in Denver, possibly during the weekend and hopefully at a local State Park. If you can’t travel far out of Denver my colleague David Bettman and I already have a moth-talk scheduled for July 25th at Bluff Lake Park Nature Center which will be followed by a black light sheet (this event will appear separately on the map below). I hope you can join a moth week this year!
View 2013 NMW USA in a larger map
For this Monday’s Moth I thought I’d post a brief tutorial on how to accurately determine the sex of moths. While there are lots of examples of sexually dimorphic species (where males and females are obviously different), the vast majority of moths are not. Saturniidae make our lives easy by having strikingly different antennae between the sexes. For example you can see the large, plumose antennae of this male Dryocampa rubicunda below. The corresponding females have antennae that are thread-like in comparison. Every time you have two moths with antennae this different then it’s fair to call the larger ones male. Usually these will be Saturniidae, but occasionally some hawk moths, tiger moths, and a scattering of other groups have antennal dimorphism. Most moths out there do not have these obvious differences, or you only have one specimen with no counterpart to compare it to, and so it takes a little more detective work to figure out what sex they are.
There are two places left to check – the tip of the abdomen and the frenulum under the wings. Male moths have claspers – or spatula like folds of their genitalia that physically grab onto the female while mating. Frequently you can see the outline of these claspers which look like a pair of folded hands on the underside tip of the abdomen. If no split is seen at the tip of the abdomen then it usually is a female. This technique can work well for butterflies since they don’t use a wing-coupling device like a frenulum, but may not be successful in hairy moths where the structure of the abdomen is obscured.
Most Lepidoptera have some mechanism for keeping their wings together in flight. Basal orders like the Micropterigidae and Hepialidae have a simple thumb-like process that comes off of the hindwing to help couple the with the forewing. But the vast majority of moths use a frenulum-retinaculum. This illustration from Wikipedia perfectly illustrates the mechanism and the sexual dimorphism. For some unknown reason female moths have multiple smaller bristles while males have a larger single one. Perhaps the multiple bristles provide greater support for an egg-laden female, whereas the single bristle provides more flexibility and power for males. But I don’t believe any hypothesis has ever been tested.
To better illustrate this here is the underside of a male Apamea aurinticolor (Noctuidae) with the frenulum clearly visible on the right. On the left the frenulum is tucked into the retinaculum on the forewing – note this structure is a clump of tightly curled scales on the costa of the forewing – not that patch of hairs that point upwards. The second image is the same moth at a higher magnification with the frenulum colored in green. Sometimes you have to tease out the frenulum from hiding to determine what’s going on – a pin that has been pushed down onto your desk will create a tiny little hook perfect for this job. Occasionally you might break the frenulum, but that’s no major loss if you lose only one and you record the sex on the label.
Here is a female Autographa mappa (Noctuidae) that faintly shows the 3 bristles that make up her retinaculum. Click to embiggen on Flickr.
I love digging through the abyssal pit of internet crazy because I get to find gems like this: The Mothman on Mars? Linked in the ‘article’ is a NASA Curiosity rover photo, Mastcam Right. SOL 194. Photo taken on 21 February 2013. The rock they are talking about as “mothman” is in the upper left corner – the triangular one casting a shadow (I added my own arrow).
I can’t see it, at all… I see a rock, that looks like a rock and probably flies like a rock. But you’ve got to love crazy anomaly hunting.
Today’s moth is a beautiful species from the Rocky Mountains outside of Denver, Epermenia stolidota (Epermeniidae). This is actually a larger specimen than it appears, about 20mm from wingtip to wingtip. Those raised, darkened, tufts of scales on the posterior edge of the forewing is a great character for this family, as well as the stiff bristles on the hind tibia (also somewhat visible here). There are 11 species in 2 genera in the United States, with likely a few more to be discovered. Fellow curatorial assistant David Bettman keyed this species out using the revision of the Nearctic species: PDF here.
This week I’m sharing a tiny, scruffy, and semi-competently spread Nepticulidae in the genus Stigmella from the same light trap of Prescott Arizona as the past few Monday Moths. I usually wouldn’t share a photo of a moth that isn’t in the best condition, but I’m using this as an example of technique. Not only was this 4mm moth pulled out of the bottom of a light trap, but it was field pinned and dried for over a year and a half. I’ve always heard that it can nearly be impossible to deal with the smallest of the small; and for the most part I haven’t. I used to think you need to capture them off of a light sheet alive in a vial and euthanize moments before spreading, all while never, ever let them dry the tiniest bit beforehand. But as it turns out, you can get away with a decent specimen by relaxing 24 hours and spreading upside down. Of course if you have a perfectly fresh specimen that avoided the blender of a bucket-trap it would make for a far superior specimen. Better yet, you pulled the leaf mine and reared the moth yourself. Most of these Nepticulidae are host-specific and far more diverse than we have given them credit. I’ve heard there could be at least 100 new species awaiting discovery in the US alone.
The story of many San Francisco butterflies are well known and depressing. The area has been heavily impacted by human development for over two centuries and is the infamous home to the first known example of an extinct American butterfly, the Xerces blue. While other butterflies are hanging on, or getting help to hang on like the Mission Blue, some like the Bay Checkerspot have continued to decline despite valiant efforts for reintroduction. Today, the only known colony of the Bay Checkerspot is within Santa Clara County on a site called Coyote Ridge. It was twenty one years of intensive study of the checkerspot in the 1960′s and 70′s by the famous biologist Paul Ehrlich that provided the impetus for federal listing in 1987. As of 1998 the colonies he studied have since gone extinct. Here is an excerpt from a 1980 paper in the Journal of the Lepidopterists’ Society “Two California Checkerspot Butterfly Species, One New, One on the Verge of Extinction” (.pdf).
“The Bay Checkerspot is already an endangered butterfly. This sad situation is all the more distressing since its populations are among the best known – ecologically and genetically – of any invertebrate. We are attempting to get official protection for E. e. bayensis and are designing some experiments to recolonize areas of suitable habitat that are now vacant.”
All efforts to relocate this butterfly have failed, and the future of this animal is not looking bright.
And so what exactly is this creatures name? In 1937 Robert F. Sternitzky described what he thought to be an overlooked San Francisco butterfly “Euphydryas editha var. bayensis“. Those early descriptions of variations and races are roughly equivalent to today’s subspecies – and so the butterfly remained bayensis for decades and became a mascot for conservation. But where was the very first Euphydras editha from and how did the San Francisco bayensis differ? Unfortunately the original description is vague and the collecting locality is simply listed as “California”, as was the unfortunate habit of Boisduval who described the butterfly 1852. But all hope is not lost since the famous French Lepidopterist was having specimens sent to him by the earliest California Lepidopterist, Pierre Joseph Michel Lorquin. An eager gold prospector and butterfly collector, Lorquin traveled California from 1849 to 1858 and again in 1869. Every butterfly that was sent back to France was a new species and subsequently described by Boisduval – who of course named one of California’s most beautiful butterflies after Lorquin.
Enter Emmel, Emmel and Mattoon in 1994 who were writing the Systematics of Western North American Butterflies. In the process of cleaning up the mess of these early western species they had to designate a Lectotype for E. editha editha since Boisduval never fixed a Holotype in 1852. Essentially he named a new species without designating the taxonomic standard for the group, making future work ambiguous for taxonomists. Thankfully the travels of Lorquin have roughly been documented and we can ascertain that he should have been in San Francisco around 1849. Comparisons of the original specimens to the Bay Checkerspot made for an overwhelming case that it was this butterfly that was sent to France in the 19th century. The result of this finding therefore places the Bay Checkerspot Euphydryas editha bayensis into synonymy with the older name Euphydryas editha editha. The name bayensis effectively dissappeared because it was a re-description of a butterfly that was already known.
Euphydryas e. editha as it turns out has been known from coastal California from the bay region down to San Luis Obispo – and so voila, the range of the Bay Checkerspot just exploded. But of course the story isn’t that simple and the butterfly didn’t become magically safe with a name change. Conservation groups and ecologist kicked and screamed and refused to accept the change, even the Xerces Society hasn’t jumped on board with the consensus of taxonomists out of what I can only assume is fear of the appearance that their butterfly is no longer endangered.
I’ll emphasize that this doesn’t mean that the populations in the bay are no longer threatened – there is still a need for protecting these biologically significant populations as they are significantly declining. Habitats all throughout the region are facing ongoing and pernicious threats (pdf). All in all the name change is trivial, we can now call the Edith’s Checkerspot the Bay Checkerspot, and still fight to protect this butterfly. I’m unsure of what would be required to amend the federal register, and if it’s at all possible to expand protection of an animal like this without re-petitioning the endangered species act. So perhaps I can understand the failure to embrace the name change since from the outside it looks like their bug is no longer endangered. On the other hand, this could bring attention to populations of a butterfly that have been overlooked for decades.
Many thanks to John Pelham for conferring with me over this taxonomic headache.
How about another unidentified Gelechiidae from the same location as the previous specimen (nr. Prescott Arizona). I’m taking a stab at this moth being in the genus Chionodes – and it is superficially similar to the species C. continuella. Thankfully there is a monograph of this group (Moths of America North of Mexico, fascicle 7.6) and I will be able to dissect and hopefully arrive at a better identification. The genitalia of moths are wonderfully sclerotized structures that can provide a wealth of characters used for identification. I’ll have to be sure to share images of what the genitalia look like soon!