[leps-talk] Monarch question

[Chris J. Durden]

At 12:45 PM 2/17/2002 -0800, you wrote:
>Woody Woods wrote:
> >
> > Regarding heritability of migratory strategies, it might be worth 
> mentioning
> > that there are Monarchs in Costa Rica that are considered a separate
> > subspecies, Danaus plexippus megalippe, thought by Vane-Wright and 
> Ackery not
> > to interbreed with D. plexippus plexippus. I must say that they are
> > indistinguishable to me even with the subtle markers these authors mention,
> > though I am no expert there.
>
>Chris Durden has suggested there are subtle phenotypic differences between
>the year round breeding populations of monarchs that exist in the lowlands of
>Mexico and the migratory monarchs of the northern USA and Canada.
>
>One difference he has noted is that the former has white apical spots
>near the tips of the forewings whereas the latter has consistently orange
>apical spots.
>
>However, I have found that very roughly 1 in every 200 migratory monarchs
>from the northern USA also has the white apical spots.  For example, all three
>monarchs in the picture below were collected in Iowa in September during
>the fall migration from overnight aggregation sites:
>
>http://www.saber.net/~monarch/apical.jpg
>
>Paul Cherubini

Paul,

1:200 seems high. I do not find them in Central Texas and I am always looking.
    On your Iowa specimens notice the shorter wing apex on the white spot 
individuals. The wing tips are even shorter in lowland individuals I have 
seen from Mexico. I suspect that your Iowa white-spot individuals may be 
hybrid offspring of "typical" X "lowland", from matings where the two occur 
together in winter on the Gulf Coast of Tamaulipas and Veracruz.
    Do you ever find the white spot phenotype in California. Klots 
mentioned that they occur rarely on the East Coast as far North as New Jersey.
    The material I have seen from Australia is "typical", not "lowland". 
Has anyone seen the white spot phenotype in any of the Pacific Island 
populations, Australia or New Zealand. Does anyone know how many millions 
of individuals there may be in these exotic introduced populations.
...................Chris Durden






 
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