[leps-talk] MALE x FEMALE emergence

[Nigel Venters]

Neil Jones wrote:
> The simple explanation as to why males usually hatch first is that they
> develop quicker, being smaller. The larvae pupate earlier and therefore
the
> adults emerge earlier.

Well this is an easy explanation that I have seen written many times
before...but I ask myself...why? If it were not advantageous for the males
to hatch first (generally)...then they wouldn't have developed this strategy
in the first place....also using your own rule of thumb...if we apply it to
the original question...then we must assume that all gregarious species...
where the females hatch first..... the females will be smaller than the
males...I don't think so. There must be more to it than this. Try some hand
pairing with Papilio or Nymphalid males less than 3 days old and see how you
get on.
Nigel

----- Original Message -----
From: "Neil Jones" <neil at nwjones.demon.co.uk>
To: "Nigel Venters" <nigelventers at ntlworld.com>; <bizarro at bio.ufpr.br>;
<leps-l at lists.yale.edu>; "leps-talk" <TILS-leps-talk at yahoogroups.com>
Sent: Thursday, May 23, 2002 7:37 PM
Subject: Re: [leps-talk] MALE x FEMALE emergence


> On Monday 20 May 2002 09:51 pm, Nigel Venters wrote:
> > Here's a shot at it!
> >
> > In many species males usually hatch first as their claspers and aedeagus
> > need to harden fully before they can mate successfully..often a few
> > days...this  allows some dispersion to take place to reduce the chance
of
> > pairing with a female from their own brood.
>
>
> I don't think that this is the ultimate reason for males emerging earlier.
> When you look at the length of the adult life span ability to harden and
mate
> earlier would be likely to be subject to high evolutionary pressures.
> It would be unlikely that evolution would deliberately delay mating
> for this reason alone. Even the dispersal argument wouldn't necessarily be
> advantagious. It depends on the size of the population in small
populations
> The Allee Effect could even increase the risk of local extinctions.
>
> The simple explanation as to why males usually hatch first is that they
> develop quicker, being smaller. The larvae pupate earlier and therefore
the
> adults emerge earlier.
>
> There are other intincitve mechanisms that work against sibling matings.
> Instictive measures like this are not uncommon. There is one in Homo
sapiens.
>
> > Maybe in gregarious species...as there is a high concentration of the
same
> > brood in exactly the same place...nature by allowing the females to
hatch
> > first causes an even further dispersion to occur before the males from
the
> > same brood to hatch, mature and start to pair, thus making it unlikely
to
> > pair with a sibling. Nigel
> >   ----- Original Message -----
>
> --
> Neil Jones- Neil at nwjones.demon.co.uk http://www.butterflyguy.com/
> NOTE NEW WEB ADDRESS
> "At some point I had to stand up and be counted. Who speaks for the
> butterflies?" Andrew Lees - The quotation on his memorial at Crymlyn Bog
> National Nature Reserve


 
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