Introductions

[Michael Gochfeld]

I don't disagree with Paul's response to my hedged (but grammatically incomplete message) on the causes of butterfly die-offs and the possible attribution to pesticide spraying for Gypsy Moths. 

Several people with some knowledge of NJ butterflies in the 1950's have questioned the relationship to Gypsy Moth spraying and several others seem confident of a causal connection.  Although die-offs, crashes, explosions, etc, are not new, it seems highly coincidental that so many crashes occurred approximately during the decade when the spraying began in earnest (note the hedge again). At least in northwestern NJ it's NOT due to habitat fragmentation. 

But I do acknowledge alternative explanations. For example, during the 1930's the systematic door-to-door destruction of Ribes (alternate hosts for the White Pine Blister Rust) eliminated important hosts of the Green and Grey Commas (Polygonia faunus and P. progne).  Maybe ground troops ARE more effective than aerial assaults. 

As far as the agricultural wisdom, however, I would argue that farmers are also well aware that some creatures become pests, usually by virtue of their high fecundity in favorable (often man-created) situations, while most species do not become pests.  None of the butterflies that disappeared from New Jersey after 1950, were of the pest nature, that would have protected them from pesticides.  Thus the survival of the Gypsy Moth in the face of repeated spraying, cannot be interpreted as evidence, that all other species (regardless of fecundity) must have survived as well. 

I have always assumed that the Gypsy Moth, an exotic species freed from its biological controls, would have had no problem proliferating more rapidly than the pesticides could kill it.  But it would seem that sooner or later, something would learn to exploit it.  Apropos of that, it must be nearly a decade since we had a major outbreak in NJ, yet they did not destroy their hosts. Was it simply that they became so numerous one year that they destroyed their forage before the larvae matured.  In which case the repeated spraying,could have  perpetuated the epidemics. 

Mike Gochfeld