Painted Lady Invasion?

[Stanley Selkow]

In article <36507FF5.717 at concentric.net>, paulcher at CONCENTRIC.NET (Paul Cherubini) writes:
|> Dennis Burnette wrote:
|> 
|> Is there a mathmatics guru on this list that knows how many Painted
|> Ladies there would have to be per square mile of land before a casual or
|> experienced observer would have a realistic chance of noticing them on
|> any given day?  Perhaps it might take many hundreds or thousand
|> individuals per square mile, depending on the assumptions that are made.
|> 
|> It seems to me we need to have a grasp of the mathmatics of the
|> situation before we can speculate on whether or not small, sporadic
|> commercial releases, usually involving 24-48 individuals, could have a
|> good chance of causing one false sighting let alone the abundance of
|> Painted Ladies that was reported in Barbados: "regularly this autumn,
|> all over the place in small numbers".


      Allow me to pose as a mathematics guru: 
           "All it takes is one or two aliens to establish a new
            population, or alter a genetically similar but locally
            adapted existing population, or introduce a new pest
            or parasite."