[HELICONIUS] optimizing Heliconius matings?

[Jamie Walters]

Dear all,

	I'd like to hear your thoughts and get your advice on how best to
set up matings among Heliconius.  I recently spent a weekend at the Niagara
Butterfly Conservatory (they have a VERY impressive rearing facility)
setting up matings between males and virgin females.  My goal was to collect
freshly produced spermatophores for proteomic analyses.  This was my first
time ever trying to set up Heliconius matings, and though I was somewhat
successful, I was also left with the impression that there was much more I
probably could have done to promote matings.  Consequently I have several
questions that I thought I'd address to the group while they were fresh on
my mind.  

	Let me describe how approached this and then I'll ask a few specific
questions.  Additional comments and suggestions are certainly welcome.

	I was working with both melpomene and erato.  My general approach
was to take recently eclosed females (between 2 and 24 hours post-eclosion)
and place them in 10-foot cages with an abundance of males taken from the
population cages (mating status unknown, but probably not virgin in most
cases).  There were nectar plants in the cage, but no pollen.  

	With erato I had several matings, usually in the early part of the
day. By the afternoon few or no matings occurred.   This was particularly
true the 2nd day, which was quite sunny, compared to the first day which was
cloudy.  Most of the matings lasted 3-5 hours, though a few went longer so I
ran out of time and I had to forcibly separate the pairs.  In these
instances there was either an incompletely formed spermatophore, or none at
all.
	With melpomene there were no matings at all.  In fact, I also didn't
observe any matings in the population cages during the 2 days I was there,
even though I was checking regularly and saw 3 matings in the erato
population cages during that same time.  

My specific questions are below, and I welcome any further suggestions or
comments about 'best practices' for optimizing mating set ups.  

Many thanks,   Jamie



1.	How long post-eclosion is 'prime' for female receptivity?
	a.	Does this differ for pupal maters like erato vs. the adult
maters like melpomene?
	b.	Does opportunity for pollen-feeding affect female
receptivity?

2.	Is it preferable to use virgin or experienced males?
	a.	If experienced, does it make much of difference to keep
males 		separated from females for some time to 'recover'?  If so,
for 		how long?
	b.	I suspect that the variance in mating duration reflects in
large 		part how 'rested' the male is (i.e. males that have mated
more 		recently will take much longer to produce a spermatophore),
but 		I had no way to confirm this hypothesis.  Does anyone else
have 		experience with this?  

3.	It was my sense that mid-morning on a sunny day is the best time for
matings.  So when trying to generate many matings, as I was, it was best to
focus efforts in the morning.  Have others found that a certain time of day
is best for generating matings?