A Puzzling Decline in Butterflies - San Francisco Chronicle 12/22/99

[Stanley A. Gorodenski]

Insecticides may not be the cause as Art Shapiro states, but I do
remember a large larva (moth?) in Costa Rica being killed by DDT(?) that
impressed me.  The area around la Pacifica was being sprayed, and I took
special care to make sure the larva did not come in contact with any
drift.  Yet, a few days later it died from, apparently, a minuscule
exposure to fumes or drift.

Stan Gorodenski

Paul Cherubini wrote:
> 
> Pierre A Plauzoles wrote:
> 
> > If the reporter truly believes that "there is no clear reason" for such a decline,
> > he/she need only look at how much insecticide is sold every year and applied to
> > our farmlands and cities.  The idea that insecticides are as "targeted" as the
> > manufacturers claim may be true, but "non-target" species are affected whether
> > they wish to believe it or not.
> 
> The article was about Prof. Art Shapiro's 28 years of monitoring
> butterfly populations in the Sacramento Valley and adjacent areas of
> northern California. Dr. Shapiro has never attributed "down" years to
> insecticide use in the area, but instead to natural events like weather
> extremes (e.g. the hard freeze in Dec. 1998 ). Similarly, Art  does not
> attribute "boom" years in butterfly populations to human activities in
> the region.
> 
> The factors responsible for the boom and bust cycles of many species
> (e.g. monarchs) are not known.
> 
> Paul Cherubini, Placerville, California

-- 
If people knew how hard I had to work to gain my mastery, it wouldn't
seem wonderful at all.  -- Michelangelo