Fall sightings and "white" Sulfurs

[Grkovich, Alex]

Hi, 

Just thought I'd add my comments re the "white" sulfurs.

First, it has been demonstrated that the existence of white females of many
Sulphur species is connected to a wide Mullerian-Batesian mimicry complex,
involving protected species of Parnassians(Papilionidae) and Whites
(Pieridae) which are Mullerian mimcs of each pother, and the white females
of Colias (Pieridae) which are Batesian mimcs of many of these.

In my experience, white females of the Clouded Sulphur (C. philodice) are
usually more frequent than white females of Orange Sulphur (C. eurytheme).
This particular season, over the past few weeks, it seems that there is an
abnormally large frequency of white females of philodice, as I wrote, for
example, in my Collecting Trip Report to northern Coos Co, NH (8/31/02). On
that particular day, in the Canadian Zone of extreme northern NH, perhaps as
many as 50% + of philodice females were white. These can be readily
determined and distinguished in flight from the equally common Cabbage
Butterflies, due to their more rapid, straightforward and less fluttering
flight. Typically the occurrence of white philodice females in the northeast
(Massachusetts) is about 25%, the same in the upper Midwest. Eurytheme white
females in the northeast are more infrequent, perhaps running around 10%.
They are more common, in my experience, in the Upper Midwest. White females
of the two can be difficult to distinguish, but eurytheme females can be
distinguished by heavier body, the longer, pointed FW, the wider black
borders, the greater number of light spots in the borders which are more
squarish, etc. To me, eurytheme also has a somewhat different flight,
quicker, more darting flight; it is also heavier than philodice and this is
noticeable at flowers, in my experience.

It has also been pointed out that the mimetic white females must not be more
common than the non-mimetic yellow females, in order to avoid the education
of predators in the matter, i.e. to avoid having too many eaten and thus
defeat the purpose of the mimicry. Therefore, non-mimetic females are
usually more common than mimetic ones, and the males are also non-mimetic
for the same reason. This is the same case in the Swallowtail species which
are involved in Batesian mimicry: males are not mimics but females are, and
in the case of the Eastern Tiger Swallowtail, some females are yellow and
are not mimics and others are black and supposedly are mimcs.

Scott also points out that white eurytheme/philodice females are able to
produce offspring more quickly than yellow ones (which is ana dvantage in
the north), but that the yellow females are more preferred as mates by the
males. This is another element in the  "balancing" between mimetic and
non-mimetic females. He also makes another interesting point when he states
that eurytheme white females are more common in the north than in the south.
I have never seen white female in the southeastern states, but they
frequently occur in the north. I have also white females of eurytheme in
Arizona. White females of the Pink Edged Sulphur are said to occur
regularly, but less commonly than yellow ones; I have to date not seen a
white female of this. For other northern species of Colias, the occurrences
of white females are as follows: Pelidne 25%, palaeno 50%; white females
occur regularly in the Rocky Mountain species as well, as far as I know.

The greenish forms occurring in the spring and fall, vernalis, is produced
by short p[hotoperiod acting on the 3rd and 4th instars of the larval stages
(Scott). The greenish undersides serves to better warm the specimens when it
basks on cool spring days. Regarding subspecies vitabundi of philodice (very
small, 1 inch + wingspan, with very narrow dark borders and very dark
greenish undersides), Norbert has pointed out that this taxon occurs much
further east of its usually described range, occurring across
central/northern Quebec, and I took a specimen very similar to this in my
backyard in Peabody, MA last Dec. 2; I am not claiming that this specimen
should be referred to as vitabundi, only that it resembles it greatly. 

I'm sure much could be added to these comments. Also, are the southwest
eurytheme placed in a different subspecies than the eastern ones? They are
in fact quite different.

Alex

> -----Original Message-----
> From:	Dale Roberts/Bill Yule [SMTP:droberts03 at snet.net]
> Sent:	Sunday, September 15, 2002 3:09 PM
> To:	leps
> Subject:	Fall sightings and "white" Sulfurs
> 
> Hank, Ted, Lenny and all.
>       I've been enjoying the good reports of fall migrants and glad to
> hear folks finding good stuff. The regular butterfly populations may have
> been off this year and it's undeniable that Monarchs and Vanessas are way
> off this year for whatever reasons besides normal population fluctuations.
> I will reserve my opinions about whether this years  nationwide Monarch
> scarcity is causally related to the weather die-off of wintering  Monarchs
> in Mexico until I have a chance to examine the whole season in retrospect
> for a while.   None-the-less there are interesting migrants around now and
> I'd like to comment on Lenny's question about "white" Sulfurs.
>  
>        First my report:   I'm seeing lots of Fiery Skippers around, mostly
> at Van Wilgrens nursery in Branford and the Butterfly Garden at
> Hammonassett, but other places too.   I asked a question on Leps-L about a
> behavior I observed but I don't think I was taken seriously because I got
> only one brief response.   Maybe someone on this list has seen this:   A
> male Fiery Skipper landed behind a female FS and repeatedly nipped at the
> end of her abdomen.   Has anyone seen this behavior?   It was suggested
> that the male was checking to see if she was mated.   Anyone agree?   That
> makes sense to me but I can't find any comment on the interpretation of
> this behavior in my meager library.   Also I finally found Cloudless
> Sulfur at Hammonassett and last week I did have a Sachem at the Butterfly
> Garden there which I was reluctant to report since I'd never seen one
> before nor had any been reported in the CT Butterfly Atlas.   Now after
> hearing reports from HG, TH and GH and reading Harry P's post ("...you
> must have Sachems up there in CT...") I'm screwing up my courage and
> reporting what I had believed all along- one Sachem, Hammonassett Beach!
> H and T's report of Ocala Skipper is exciting (another I've never seen)
> and I' ll be looking for that one too.
>      Lenny's "whites":   Most of my field guides report the dimorphism of
> both Orange/Clouded Sulfur females where-in a white form occurs with
> regularity.   How regular?  I have read somewhere that about one in ten
> females of some broods of   either eurytheme or philodice (again I don't
> remember which) are albino.   To complicate an already complicated
> situation (i.e. Orange and Clouded Sulfurs interbreed and produce hybrids
> which may or may not produce albino females??) there is also late fall
> broods of these butterflies that are extremely pale and tinged with light
> green that in some light appear on the wing to be almost white.   So if I
> understand a little about what is going on here it appears that seeing a
> white appearing Colias on the wing in September it could be an albino
> female Orange Sulfur or an albino female Clouded Sulfur (let's leave
> hybrids out of this) or it could be a late brood "pale form" of one or the
> other of these groups. (Or maybe it's a Cabbage White)   I'm really not
> helping clear this thing up very much am I?   Anyway I'm just a rookie
> with curiosity and  enthusiasm and I could be wrong about some or most of
> this but hey, it's the internet... :>).    Someone with many years of
> collecting and observation under their belt like Alex or Ron or Harry
> could probably shed much more light on this fascinating subject than I and
> maybe someone of   their caliber will respond?
>  
>         In 1898 writing in "The Butterfly Book", W.J. Holland says the
> following about Orange Sulfur:   "This species has been made in recent
> years the subject of exhaustive study and has been discovered to be
> strongly polymorphic- liable to great variation.   Not only does albinism
> assert itself in the production of white forms, but there are many
> seasonal and climatic forms.   We are not yet through with our studies..."
>  
>                                                     Cheers,
>                                                                 Bill Yule
> 
> 
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