response to Kojiro Shiraiwa

Pavulaan at Pavulaan at
Wed Jun 18 22:47:13 EDT 1997

 In a message dated 97-06-17 23:52:33 EDT, Kojiro Shiraiwa writes:
 << ...I'm worried about MORE DECLINE of butterflies. i.e., if they
  release butterflies from captivities (raised with lots of help from human
  & perhaps protection from its predators (birds, insects, bacteria, virus,
  etc), some individuals may not be suitable for wild environment.  If this
  group of weak butterflies are released and breed with all others, they
  might end up with population with weak resistance to such predators (which
  might cause rapid decrease of population).
   Some animals are not able to go back to the wild after human care, they
  die soon after release. So, think this issue should be studied more
  carefully.  >>
 I think Kojiro Shiraiwa (K.S.) is right: this issue should be studied more
carefully.  Especially since the subject has been beaten into the ground. 
 I see two polarized schools of thought on the subject here: those who fear
that rearing and releasing captive-bred butterflies will cause a catastrophic
effect on butterflies (K.S. believes that a whole population will be affected
by a resulting decline); and those who feel that any number of bred
butterflies released are insignificant to the total gene pool, that they will
have little or no effect on the overall population.
 Nature is too complex, and there are far too many variables.  Anyone out
there want to be a hero and conduct such a study?  The National Butterfly
Release will be a good case study.  Let's see if the North American Monarchs
get ravaged by a rampant disease next year, of if there is no noticeable
effect.  Don't forget, butterflies all go through unpredictable natural
cycles of abundance and decline, and one season of a few Monarch releases
will be insufficient to render a verdict.  We'll never know until somebody
does an actual study to determine what percentage of reared butterflies
suddenly develop diseases that otherwise would not have been spread by wild
 Thanks, K.S. for keeping the topic alive. 
 Harry Pavulaan
 Herndon, VA.
 P.S.: in all my years of rearing butterflies, the only diseases that
affected my "crop" of caterpillars were those which invariably proved fatal
to ALL the caterpillars themselves.  The virus that decimated the Gypsy Moth
last year may have been the same virus that totally decimated the
caterpillars of several species which I tried to rear.  It was a very deadly
virus, and 100% fatal.  No larvae made it to adulthood to spread the virus. 

More information about the Leps-l mailing list