Cocoons pupae and cofaqui taxonomy

[Ron Gatrelle]

Chris J. Durden wrote:


snip
>     Chrysalis and pupa are equivalent, but cocoon is of manufactured
silk,
> glued bits of the environment or both, as constructed by the pre-pupal
> larva. Some larvae do this too, like bagworms (psychid moths) and caddis
> flies that construct larval cases.
> ...................Chris Durden

Megathymus cofaqui in particular comes to my mind as a "butterfly" that
makes a very large and sturdy silk "cocoon".   When the larva is fully
mature and done feeding it tunnels up from the root of a Yucca to the
surface of the earth. The last eight or so inches of this tunnel will
contain this "cocoon".  The upper one to three inches will be above ground.
When collecting these I just dig the sandy soil away from this area and
pluck out the silk case with the pre-pupa or pupa inside.  At the lower end
the silk is loosely tied together and after the larva sheds its skin, the
skin is always positioned at the bottom of this chamber and completes the
lower "plug".  The top is tightly woven and exited just as a silk moth
would exit its cocoon.  The pupa is mobile and wiggles up and down the
chamber to moderate its temperature. (On cool mornings with lots of sun
they will be right at the top of the "cocoon" or "tent" soaking up warmth.)
The inside of the tube is lubricated with white powder generated from the
larva's liquid waste.  The outside of the tent is coated with the
surrounding sandy soil and what always looks to me like bits of frass.  The
fact that most of this cocoon is under ground, coated inwardly and
outwardly, and long and narrow masks the fact that this is totally a cocoon
structure.

These root boring skippers are moth like in that their flights are
crepuscular (fly mostly at dawn and dusk) beginning and ending in
semi-darkness.   Like silk moths they live off their body fats and do not
feed at nectar.

Ron

PS  What was once known as species Megathymus harrisi is now known to be
the exact same entity as species M. cofaqui cofaqui.  H.A. Freeman, who
described harrisi as a species, wrote me shortly after the publication of
my article on cofaqui (TTR 1:4, Jan. 1999) to express to me his total
agreement with my findings and conclusions as put forth in my paper.  Even
though this paper has been out in the scientific community for almost 3
full years there are still websites and publications that retain harrisi as
a species (Adam's GA Lepidoptera) or list it as a subspecies of cofaqui.
Cofaqui/harrisi is a Georgian insect as both were described from that state
and both original types exist.  In my paper I gave the FL populatons the
new name slotteni.  Thus the proper taxonomic alignment is M. c. cofaqui
(GA northward) and M. c. slotteni (mid FL southward).

Contrary to the statement on the USGS site the ranges of cofaqui and
slotteni are not "isolated" but are continuous.  As with several other
Southeastern US taxa, these dot maps only reflect collection/observation
records and not the actual range of taxa in nature in this region.  This is
to say that the "gaps" only reflect that not many people have historically
been looking for butterflies in that area of the US.


 
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