Colias

[Chris J. Durden]

At 09:41  23/02/00 -0500, you wrote:
 ......  Anyway, I have a question about these little
>guys maybe someone can help me out with.
>    The Colias butterflies I saw today were males of either philodice or
>eurytheme.  They are very small, like I would expect the early ones to be,
>and are yellow with basal orange coloring.  
.......>    However, back home in Michigan, this form is common in places
where
>philodice is much, much more common than eurytheme.  I have collected this
>form in May 
===
both the winter form of *eurytheme* and possible *eurythemeXphilodice*
hybrids.
===
and July
===
only *eurythemeXphilodice* hybrids.
===
, and the 'normal' orange form in June.  Both forms are
>roughly the same size.  It doesn't seem to make sense in terms of
>photoperiods.
===
 I think Ward Watt found that the controlling factor in the color shift of
*eurytheme* is temperature, not photoperiod.
===
>    Anyone know what's going on here?  Why have I collected full-sized
>'spring' forms in late July?
>
>Thanks.
>
>Mike Philip
>Raleigh, N. Carolina
>
===
  I have puzzled over these in the field in Quebec, Ontario, Connecticut,
Pennsylvania and Texas (where winter form *eurytheme* is abundant right
now). Apart from minor differences in submarginal spot pattern VHW and
rounder FW apex there is almost no way to distinguish *eurytheme/philodice*
hybrids from winter form *eurytheme* and there are a lot of specimens that
cannot be placed as one or the other. Some of our January *eurytheme* have
very narrow black margin and bear an uncanny resemblance to *boothi*!
......Chris
>
>