InsectNet forum

Those of you who follow my socials have already seen this but I figured I’d share this. The narration was done by a friend so pls excuse any inaccuracies such as the use of the word “deformity”.

This specimen was collected in a field I’ve collected in for many years. I was packing specimens when I spotted it. Very lucky find.

PS: I’m also doing some traveling so I’ll be MIA for a bit but will have great stories to share when I’m back.

I always assumed the below to be a deformity, not a gynandromorph.

Chuck wrote: Fri Jul 07, 2023 12:53 pm I always assumed the below to be a deformity, not a gynandromorph.

Wing color, pattern and other traits to me indicate they the right forewing is simply a deformity or dwarf wing. Possibly not fully expanded.

As you can see from my specimen the male and female sides have different shades and wing pattern.

Chuck wrote: Fri Jul 07, 2023 12:53 pm I always assumed the below to be a deformity, not a gynandromorph.

The dwarf wing merged spot’s between the marginal and submarginal wing spots are interesting though.

I'm confused. About this thread.
Speyeria cybele in the Pacific Northwest, the males and females are sexually dimorphic in a dramatic manner.
Is that simply the "leto" subspecies? Even Robert Pyle's Butterflies of Cascadia book leaves me in over my head apparently.
I would have never considered your specimen to be anything but a deformity and not a gynandromorph.

Here is an old photo, posted in Clark's insectnet.com, of the only gynandromorph I have ever collected:


This was collected in late July 1992... a year prior, in 1991, the volcano Mt. Pinatubo, in the Philippines blew it's top spewing ash high up into the atmosphere & lowering worldwide temperatures. All of the fritillaries (all buttefly spp. really) here in my area of Saskatchewan, Canada, in 1992, were very late in emerging (very cool summer) & very fresh specimens were common in late July & into August (usually appearing 1st week in July). Did the cooler temperatures have anything to do with the appearance of this odd creature?... probably not... was just a very rare, genetic aberrant.

John K.

Hi Kevinkk,
Chuck's specimen is indeed a "deformity" with its reduced wing.
However, the specimen featured by ED-tomologist is a naturally
occurring and (very rarely) seen bi-lateral gynandromorph !

Gynandromorphs occur in "varying" degrees. Most times they occur
as (1/4) gynanders OR as "mosaics" which may feature any number
of streaks or spots occurring on multiple wings.

ALL of these genetic defect butterflies are one-of-a-kinds and are
really unique (in that right). But, the real (unicorn) of the lot -- that
is the rarest ever encountered are true bi-lateral butterflies; those
featuring a perfect symmetrical division of male on (1/2) and female
on the other (1/2).

This photograph by ED-tomologist clearly shows a female
(1/2) on the left and a male (1/2) on the right.



Bi-laterals will also have only one male clasper
present.