sphinx pupae

[George Andrushko]

Hi,

I don't know how many would be interested in this subject, but it has
always been a mystory to me even though I have been in Lepidoptera all
my life. This is concerning the sphinx pupae, how do they escape from
their hard packed earth chamber, buried some 4 to 5 inches below the
surface. It may seem a rediculus question, but when you think about it,
it would be nice to know. The known fact is that they do escape.

In my earlier years I've dug many pupae, buried at the base of a tree.
In observing this, in all cases, the pupae are in a chamber with a hard
crusted shell above, probably formed when the caterpiller is getting to
shed it skin (notmal reaction of wiggling and rolling around). After the
moth forms, it is quite fragil and by no means (in my opinion) could
possibly dig its way out. But, they do emerge, and if it was not so,
they would not have endured since their creation. Most of us who raised
sphinx moths usually had loose dirt for them to crawl under using peat
moss and etc, and then dug them up a week or two later and never have
observed the actual process. Does anyone really know what happens.

I did happen to find a perfectly viable pupa natrally on the surface one
time and am thinking that they wiggle out of the dirt before they
actually emerge.

If anyone has an answer, please respond
George
-- 

George Andrushko
e-mail: andrushk at inovion.com
web page: http://users.inovion.com/~andrushk/0-main1.htm