Subject: Re: Danaus plexippus color question

From: [email-masked] (Pierre A Plauzoles)
Date: Wed, 24 Apr 1996 22:00:55 GMT

In a previous article, [email-masked] (Steve Connolley) says:

>At 08:36 AM 4/18/96 CST, you wrote:
>>Wed, 17 Apr 1996 "DANNY A. BRASS" <[email-masked]>
>>
>I don't know about the "gold
>>dots" on monarch pupae (the original question) and I can't remember if
>>they are still gold after the butterfly has departed.
>>    Perhaps some physiologists would like to make additional comments.
>
>If I am not mistaken, the gold spots on the Monarch pupae are color sacs
>that allow for the characteristic orange and black coloration of the adult.
>Careful excision of one or more of these sacs early in the pupa stage will
>produce an adult Monarch with white (or neutral) coloration on isolated
>segments of the wings.

Should this indeed be the case, there should be no gold dots on the pupae 
of the "white" adults in Hawaii, unless of course there is more than one 
factor involved.

Perhaps someone in Hawaii can enlighten us mainlanders on the matter (or 
someone who has studied that population in more detail than we have).

-- 
Pierre Plauzoles   [email-masked]
Canoga Park, California

---

From: [email-masked] (kandee kosior)
Date: Fri, 26 Apr 1996 14:18:19 GMT

Back in the 1970's, Dr. Fred Urquhart invented a device to microcauterize
the gold spots off of the pupa of the monarch butterfly. I believe he
named the gold spots "pigmented prismatic maculae".

I don't have the scientific papers he wrote with me (there was more than
one scientific paper written), but suggest that you may wish to consult
his last book, "THE MONARCH BUTTERFLY - INTERNATIONAL TRAVELLER" for the
results of these experiments.

Please contact me should you want to know what journals published these
articles.

Don Davis

[email-masked]