Saturday, January 19, 2013

Family/Subfamily Overview

I updated the "Naming Lepidoptera" page (click here or on the link in the left-side column) with two new photo-spreads.  One of these days I'll get around to adding a short description of each family and subfamily, but for now I thought my readers might like to see some pretty pictures!  The colors are slightly skewed because of the PDF/JPEG conversion, but you get the idea.

Monday, January 7, 2013

Fritillary Follow-up

After the last post about fritillary identification, I thought it might be useful to follow up on the photos I used for the "test" section, explaining how I have determined their identification.  If you haven't taken the test yet, please read the Fritillary Frenzy post first, before reviewing the explanations listed here.

A - Hydaspe Fritillary Argynnis hydaspe
If you said this was a Northwestern Fritillary because of the lighter submarginal/postmedian band, note that it still has a red tint to it, more pink than the yellow-beige of the Northwestern Fritillary photos I've shown. Also, the upper three cream spots in the center band are oval-shaped, not pointed (compare with #D below).  All other species in the test have silvered spots, except the Mormon Fritillary which can also be both silvered or unsilvered, but the brick-red color identifies this as Hydaspe.

B - Zerene Fritillary Argynnis zerene
This is an average-looking Zerene: rounded silver spots, beige VHW ground color with reddish-chocolate overtones.  It is a little more reddish than some specimens, but not red enough to be Hydaspe, plus it has silvered spots.  It is too dark and the silver spots are too rounded to be Callippe.  It may be confused with Coronis because the silver spots have a little more black around them than some of the other Zerene photos I showed, but the complete lack of olive/green scaling on the VHW identifies it as Zerene, not Coronis.

C - Great Spangled Fritillary Argynnis cybele
The size of this specimen (2.5 inches) would give it away as Great Spangled if you saw it in person.  It might have been confused with the Aphrodite Fritillary but as I mentioned before, I don't have any photos of those.  The reduced size of the black spots on the dorsal side, and of the silver spots on the ventral side, give this away as a Great Spangled Fritillary.

D - Northwestern Fritillary Argynnis hesperis
Unsilvered spots, so it has to be either Northwestern, Hydaspe, or Mormon.  The discal area is too dark to be a Mormon Fritillary, and not red enough to be Hydaspe.  In addition to that, the submarginal/postmedian band is yellow-beige, not pinkish like Hydaspe, and the center band of cream spots are much more pointed than Hydaspe's spots.

E - Zerene Fritillary Argynnis zerene
This is one of the tricky specimens I talked about, the silver spots appear to be ringed with more black, so don't feel bad if you thought this was a Coronis Fritillary!  The first clue is the ground color of the VHW; it is a light orange-brown with hints of rust, not yellow-brown and olive like the Coronis.  The second clue is the black band across the middle of the dorsal hindwing (DHW); it is much wider than in male Coronis (see #L below).  The black would not be a reliable indicator if it were a female, but male Coronis are almost always more finely marked on the dorsal surface than Zerene.

F - Hydaspe Fritillary Argynnis hydaspe 
I picked this specimen because some of the cream spots are a little more elongated than average Hydaspe, and the submarginal band is a little lighter because this is a slightly faded/older individual.  As I explained for specimen #A above, the VHW ground color is brick-red, not chocolate-brown as in the Northwestern Fritillary, and the submarginal band still has a pinkish-tint to it, not the yellow-beige seen in the Northwestern.

G - Coronis Fritillary Argynnis coronis
This is the other tricky specimen I was referring to, and the only one here that I am not entirely confident about, so if you thought it was a Callippe or Zerene, you might actually be correct, but I will explain why I believe it is Coronis.  It is a female, which makes it even more difficult to determine, because the standard markings that make the males easier to identify are a little different.  This is one of those cases where you can't really make the determination based on a single aspect, such as color or spot shape, but taken together they point towards one species.  Please feel free to argue with me on my following explanation, it might help one of us come to a stronger conclusion!
1. Overall size.  You can't tell from the photo, but this is a larger butterfly (2.25 inches).  Female fritillaries tend to be larger than males anyway, and 2.25 inches is not uncommon for Zerene and Callippe, but a larger size often points towards Coronis.
2. Separating it from Callippe.  The silver spots are a little more elongated and slightly pointed than the average Coronis, which would seem to point more towards Callippe (also read my explanation for #L).  However, the spots do not fill the VHW quite as much as Callippe usually do, and there is no greenish dusting of scales over the whole surface.  The base color has a little bit of a greenish tint common to Coronis and similar to Callippe, but the markings are still sharp, not entirely clouded over like Callippe often are (see #H, male Callippe in the photo below).  If you are saying "now wait a minute, what about that first female Callippe in the last post?" (see here), yes I know it looks an awful lot like this one, and I'm not 100% sure on that identification either.  However, notice that the ground color in that specimen is much more even-toned, not darker in the discal area like in this specimen above, and the silver spots (of the "Callippe") aren't quite as sharply framed as in this one (#G, "Coronis").
3. Separating it from Zerene.  The VHW ground color is more yellowish/greenish-brown and chocolate, with almost no hint of the rust-coloring you see in Zerene.

H - Callippe Fritillary Argynnis callippe
I included this Callippe male because the VHW appears to have slightly better-framed silver spots, possibly leading you to confuse it with Coronis.  It is a little more difficult to identify butterflies from photos, because you can't see the actual size and are not able to tilt it in different directions to see subtle coloring that is washed-out or incorrectly reflected in the photo.  In this case, it is a little harder to see in the photo, but this butterfly has a greenish cast over the entire VHW, slightly clouding the silver spots and giving it a dirty appearance, leading to the identification as a Callippe and not Coronis.  Also, the silver spots cover the wing a little more completely than Coronis; it is a subtle difference, but flip back and forth between this (#H) and the image above (#G) and you will begin to see what I mean.  Pay particular attention to the silver blotches in between the major spots.
On a side-note, this is actually a slightly-aberrant specimen; the tips of the forewings are not missing scales as it appears, the scales are there but lack normal coloring, while the rest of the butterfly is normally-marked.

I - Mormon Fritillary Argynnis mormonia
This is a case where it would be a dead give-away if you saw this specimen in person, because it is smaller than all the others shown here, with a wingspan just over 1.5 inches.  I knew that without a size reference you would have to depend on other points of identification, so I chose a specimen that had a lighter VHW ground color and silvered spots, similar to Zerene.  The difference is that this does not have the reddish-tint in the VHW color you see in Zerene (#J, below), and the black markings on the dorsal surface are much smaller than Zerene.  Although the spots are silvered, there is still a cloudy appearance that you will not see in Zerene, and this cloudiness also eliminates any defined framing of the silver spots that you would see in Coronis.

J - Zerene Fritillary Argynnis zerene
This is another standard-looking Zerene, similar to #B.  The silver spots are not large or elongated enough to be easily confused with Callippe, and the VHW color has no trace of green that would be seen in Callippe and Coronis.

K - Coronis Fritillary Argynnis coronis
This is another female Coronis, similar to #G but a little more typical.  The marginal (outer) row of silver spots on the VHW is strongly rounded, and the silver spots do not cover the discal area as widely as Callippe.  The VHW ground color is a little too greenish to be Zerene in my opinion.  Flip quickly back and forth between the Coronis, Zerene, and Callippe photos in the Fritillary Frenzy post, and hopefully you'll start to see the subtle differences in color (Coronis v. Zerene) and spot shape/size (Callippe v. Zerene and Coronis).

L - Coronis Fritillary Argynnis coronis
This is an average-looking Coronis male.  I included it so it would be sort of a give-away and comparison for some of the other specimens shown.  In the Fritillary Frenzy post, I mentioned that the rounded or pointed/triangular shape of the outer row of silver spots is not a reliable marker for determining Coronis vs. Callippe, but this is one case where it is.  Callippe will always have triangular marginal spots, although they are sometimes blunted.  Zerene varies widely between flat, rounded, blunted triangle or sharp triangle spots.  Coronis tend to be flat or rounded but occasionally approach a triangular shape, such as #G above.  The male shown here has the distinctly-framed silver spots typical of Coronis, and the VHW base color is much more yellow-beige with greenish overtones compared to Zerene.

Saturday, January 5, 2013

Fritillary Frenzy

Update 1/6/2013: I corrected a few places in this article referring to basal, discal, submarginal, and postmedian, and I have added a new page to my blog that builds on a post from last June, click on "Wing Terminology" in the contents bar on the left, or go here.
If you have spent any time trying to identify that large black-speckled orange butterfly in your net or on a flower, you may have joined the club of frustrated fritillary observers.  I used to be in that category, and still revert to it frequently, usually when I haven't compared the different species recently to refresh my memory.  Because of this, I'm surprised I haven't thought to write a blog post about identifying fritillaries (or "frits" as many butterfliers call them for short), but thanks to a commenter on my last post who suggested this, here is an illustrated guide to identifying the seven species of "greater" frits that I am familiar with.
This is going to be a longer article than normal, and you may want to print and keep it for a quick reference.  All photos are my own, so please do not reprint or distribute them for other purposes besides your personal use without asking (comments on my blog are sent to me for approval and won't show up until I post them, so that is the best way to contact me if you have questions).
Fritillaries can be divided into two groups: greater and lesser. As the names suggest, greater fritillaries are larger, usually with a wingspan between 1.5 and 3 inches, compared to the 1 to 1.5 inch wingspan of lesser fritillaries.  Greater fritillaries belong to the genus Argynnis, and lesser frits belong to the genus Boloria.  The genus name of greater frits was recently known as Speyeria and most sources still use that name, although new (post-2010) publications are starting to use the genus Argynnis, as it is the officially-recognized genus now.  While it may be confusing to many people, it is necessary to follow the rules of taxonomy, and Argynnis is the original, historic genus name (see my explanation of the naming process here, and refer to the ICZN website).
Both greater and lesser fritillaries have orange wings with black markings on the dorsal (upper) side.  The ventral side of North American Argynnis is usually marked with silvered or unsilvered spots, and the ventral of Boloria species is usually marked with bands and spots in shades of purple, rust, orange, and white.  Lesser fritillaries are easier to tell apart than greater fritillaries, and will not be described in this article.  There are ten species of greater fritillaries in the Pacific Northwest:
Great Spangled Fritillary Argynnis cybele
Coronis Fritillary A. coronis
Zerene Fritillary A. zerene
Callippe Fritillary A. callippe
Great Basin Fritillary A. egleis
Northwestern Fritillary A. hesperis (unsilvered and silvered forms)
Atlantis Fritillary A. atlantis
Aphrodite Fritillary A. aphrodite
Hydaspe Fritillary A. hydaspe
Mormon Fritillary A. mormonia
I have not had the opportunity to collect or photograph the Great Basin, Atlantis, and Aphrodite fritillaries (A. egleis, atlantis, aphrodite), so these three species will be briefly discussed as a group.  Refer to the Butterflies of America website for an excellent database of photos to help (or further confuse!) you.  The "thumbnail" pages there are organized by subspecies/segregate, and you can click on the photos to see larger versions, or click on the subspecies name to see the full page.  I have hyperlinked the names in the list above to the thumbnail pages for each species for your convenience.
All of these ten species feed on violets as larvae, thus the adults are frequently associated with meadows and prairies where their hosts can be found.  Adults of some species have been known to migrate between higher and lower elevations throughout the Spring and Summer, following the seasonal blooming of flowers (adult nectar source) and growth of violets (larval host).
Another species that is an occasional stray to parts of the Northwest is the Variegated Fritillary (Euptoieta claudia).  It is not in the same genus as the other frits discussed here, and is a somewhat tropical species that sometimes strays into Montana and parts of British Columbia and Idaho, but has not been recorded in Washington or Oregon.  Although it resembles our greater fritillaries and may be mistaken for one of them while in flight, the black dorsal pattern is quite different, and the ventral lacks the silver/cream spots of the Argynnis species listed here.
Most of these are my educated guesses, some are what I found online.
Speyeria   spay-air'-ree-ah
Argynnis   ahr-gyn'-ness  (probably a hard g, but not sure)
cybele       sih'-bell-ley
zerene       zer-ree'-ney
callippe     kuh-lip'-pey
egleis        egg-lay'-iss (not certain about this pronunciation)
hesperis    hess'-per-iss
aphrodite  aph-ro-dye'-tey
hydaspe    hi-dass'-pey
Great Spangled Fritillary Argynnis cybele
Overall impression: large butterfly, reduced VHW silver spots
Largest of the ten species listed here, with a wingspan of 2 to 3 inches.  The females are much lighter than the males, and look like Mourning Cloaks (Nymphalis antiopa) when in flight.  On both males and females, the silver spots on the VHW are smaller than those of the other Argynnis species.  The VHW is distinctly separated into two ground colors: reddish-chocolate in the discal area and light beige in the postmedian band.  This ground color pattern is very similar to the Northwestern, Atlantis, Aphrodite, and Great Basin frits, but these four can be distinguished from the Great Spangled by their overall size, and the appearance of the silver VHW spots.
Male Great Spangled Fritillary, Sinlahekin Wildlife Area, Okanogan Co. WA
Female Great Spangled Fritillary, Sinlahekin Wildlife Area, Okanogan Co. WA
Coronis Fritillary Argynnis coronis
Overall impression: average size, olive/light brown VHW ground color, silver spots appear to be lightly ringed in black
Wingspan averages around 2 inches.  Dorsal black markings appear slightly narrower (less bold) than Zerene and Callippe, especially in the males.  The VHW ground color is yellowish-brown with olive highlights, and the males in particular have a greenish appearance similar to Callippe.  Female Coronis are easily confused with female Zerene and Callippe fritillaries.  Both males and females are distinguishable by their yellowish or light-olive VHW ground color from Zerene, which has tinges of rust.  Coronis are distinguisable from Callippe by their less-elongated silver spots ringed with a hint of black.
Male Coronis Fritillary, upper Reecer Creek/FR 3507, Kittitas Co. WA
Female Coronis Fritillary, upper Reecer Creek/FR 3507, Kittitas Co. WA
Zerene Fritillary Argynnis zerene
Overall impression: average size, average orange-brown VHW ground color, silver spots are medium-sized and mostly rounded
Wingspan averages around 2 inches.  Dorsal color and black markings are darker than Coronis.  The VHW ground color is tawny brown with rust-colored highlights.  Silver spots are rounded, not as elongated as the Callippe.  Some sources describe the marginal row of silver spots on both the VFW and VHW as being blunt or oval in Coronis and Zerene, and pointed or triangular in Callippe, but as you see in the photos here, these spots are sometimes triangular in Zerene and Coronis, so this is not a reliable indicator.
Male Zerene Fritillary, Sinlahekin Wildlife Area, Okanogan Co. WA
Male Zerene Fritillary, Sinlahekin Wildlife Area, Okanogan Co. WA
Female Zerene Fritillary, Sinlahekin Wildlife Area, Okanogan Co. WA
Callippe Fritillary Argynnis callippe
Overall impression: bold black, washed-out orange, elongated VHW silver spots
Wingspan averages around 2 inches.  Dorsal black markings are bold, orange often appears washed-out, with ventral silver spots seeming to shine through to the dorsal surface, similar to but more obvious than in female Zerene fritillaries.  The VHW has a greenish cast over the yellowish-orange ground color, similar to the Coronis, but the large size and elongated shape of the silver spots distinguish Callippe from that species.
If you use R. M. Pyle's Butterflies of Cascadia for reference, make a note on page 270 that the photo is actually a Coronis Fritillary, not a Callippe as indicated. I'm sure the author won't mind me mentioning that, as he was the one who pointed it out to me.  You'll note in that photo that although the spots appear to be rather large and elongated, they do not nearly cover the VHW surface as you see in the specimens shown here.
Male Callippe Fritillary, Sinlahekin Wildlife Area, Okanogan Co. WA
Female Callippe Fritillary, Sinlahekin Wildlife Area, Okanogan Co. WA
Northwestern Fritillary Argynnis hesperis
Overall impression: pointed/sharp VHW spots
Wingspan averages just less than 2 inches.  The VHW spots can be silvered or unsilvered and cream-colored, and the median row of spots (outer row of the discal area) is almost always quite pointed (see the male in the photos below).  The VHW is also distinctly divided into two ground colors: the disc is reddish-brown and the postmedian band is light beige.
Northwestern Fritillary Female (top, SWA, Okanogan Co. WA), Male (bottom, upper Reecer Creek, Kittitas Co. WA)
Aphrodite, Atlantis, and Great Basin fritillaries (A. aphrodite, A. atlantis, A. egleis)
As mentioned before, I am not familiar with these three species, so this description is only what I have observed from the photos on the Butterflies of America website and my field guides.
Aphrodite may be slightly larger than the other three species. Also, according to Butterflies of British Columbia (Guppy & Shepard), the second brown spot (from the body) in the postmedian band has a faint brown halo around it. You can see it in most of the photos on the BoA website, particular this one here.  Aphrodite also seems to have silvered spots, compared to the usually unsilvered Northwestern Fritillary.  To me, it looks a bit like a cross between Great Spangled and Northwestern fritillaries.
Atlantis used to be combined with Northwestern as one species.  The VHW is generally darker, more of a dark chocolate color than rust.  It is also a more northern species, having never been recorded in Washington (historic records are now all described as A. hesperis in WA), ranging through British Columbia, Alberta, and northern Idaho and Montana.
Great Basin appears to me more like Zerene in color and pattern, but has slightly shorter wings, sort of stubby-looking.  It is a more southern species, ranging from California and Nevada up through eastern Oregon and parts of eastern Washington, into Idaho and Montana.
Hydaspe Fritillary Argynnis hydaspe
Overall impression: dark and red
Wingspan averages just less than 2 inches.  The VHW spots are usually unsilvered and cream-colored, although the marginal row is occasionally lightly silvered (2nd and 3rd specimens in the photos below), and the spots in the discal area tend to be almost square compared to the Northwestern Fritillary.  Hydaspe can be easily initially identified from a distance simply by seeing the deep reddish-orange color of the dorsal side, but verification of the species comes from the VHW color, which is the deepest rust color out of all the other species described here.  Individuals that are faded may sometimes be confused with the Northwestern Fritillary and the others in that group, but the postmedian band of Hydaspe still has a reddish color, compared with the yellowish postmedian band of the Northwestern Fritillary.
Male Hydaspe Fritillary, Sinlahekin Wildlife Area, Okanogan Co. WA
Female Hydaspe Fritillary, Sinlahekin Wildlife Area, Okanogan Co. WA
Mormon Fritillary Argynnis mormonia
Overall impression: small, finely marked, ventral is bright yellow-orange
Smallest of the "greater" fritillaries with a wingspan averaging 1.5 inches.  The black dorsal spots are cleanly marked.  There are two general forms of Mormon frits, one has bright, silvered spots and a VHW base color of light tawny orange, while the other form has a greenish sheen over the VHW, and the spots are lightly-silvered or unsilvered.
Male Mormon Fritillary, various locations in WA
Female Mormon Fritillary, Haney Meadow and vicinity, Kittitas Co. WA
Ready for a test?
Here is a set of photos to test your abilities.  None of them are included in the photos above, so you can't match them up that way.  There is at least one photo for each of the seven species I described (no Aphrodite, Atlantis, or Great Basin), but I included a few extra photos to make it harder, including two females that resemble other species.  Two specimens in particular are quite tricky, and I'm not even sure I have them identified correctly, so they will be marked with an asterisk* in the answers.  Write down your best guesses, and then check the answers at the end of this article (below the conclusion paragraph).  Explanations of their identification will be in a separate blog post next week.
I hope that this guide has helped you to understand the differences between these species, and given you the confidence to try your hand at identifying the next frit you see.  Keep in mind that while you may be able to see the differences between these specimens, when you are holding a fritillary in your hand and trying to identify it, you may find yourself confused all over again.  I have to refresh my memory every Spring in order to maintain any semblance of proficiency at correctly identifying these critters!  After some practice, it will become second-nature for you to take a quick glance and simply "know" that an individual is a particular species, without having to carefully examine the markings and define how you came to that conclusion.  Also keep in mind that these butterflies are variable, some species more so than others, therefore it is helpful to study series of photos such as what I have provided, and what the Butterflies of America website makes available. That way, you can compare the variations and decide which best matches the one you have.
Happy chasing!

All photos and text copyright Caitlin C. LaBar

Photo-test Answers: A - Hydaspe male; B - Zerene male; C - Great Spangled male; D - Northwestern male; E - Zerene* male; F - Hydaspe male; G - Coronis* female; H - Callippe male; I - Mormon male; J - Zerene male; K - Coronis female; L - Coronis male