I need help.......
Kenelm Philip
fnkwp at aurora.alaska.edu
Fri May 5 06:00:25 EDT 2000
Paul Cherubini said:
> During the 14 years from 1986 to 2000 no more fresh Painted Ladies were
> seen in the Fairbanks region despite continued school releases during this
> period.
> Thus it appears the chance that the faunal record database would record a
> false positive due to school releases is extremely low.
The chance of such a false positive cannot be estimated from the absence
of captures 1987-2000, for the simple reason that I am the only collector
involved in the Fairbanks area--and most summers I am off at some remote
site (Yukon, NWT, Russia, northern or western Alaska) during the relevant
time period. "Absence of proof is not proof of absence."
> ...do the occasional sightings of worn specimens on the Kenai peninsula
> (presumably somewhat near Anchorage) really prove natural Painted Lady
> dispersal to coastal Alaska from Mexico or the USA?
One can never be sure about a given specimen--but there is enough
evidence that SW US butterflies can disperse this far north. Both _V.
cardui_ and _V. atalanta_ have been found in the Yukon (Carmacks and
Haines Junction, respectively), and _V. atalanta_ has been found in SE
and Southcentral Alaska. There is also one record of _H. isola_ from
Wiseman, Alaska. All these species are noted for northward dispersal
flights...
The Kenai Peninsula _cardui_ were caught in 1973, which may
have been before the schools up here began releasing them--but I'm
not sure about that.
I also remember the summer of 1975, when the geometrid _Rheumap-
tera hastata_ (which normally occurs in taiga) suddenly appeared on the
arctic coast of Alaska, and also in the interior of Victoria Island
where I was collecting. There had been strong south winds for several
days, and the moth was having a major outbreak in the taiga. I had not
expected to find that species flying (in some numbers) in arctic rock
desert well before the local butterflies had emerged...
Ken Philip
fnkwp at uaf.edu
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