Butterfly releases redux

[Paul Cherubini]

> There is little direct evidence either way about the harm done to
> populations or metapopulations of butterflies by increasing rates of
> migration. There is general theory on epidemiology that shows that it
> all depends on the disease, the migration rates, the distribution of
> alternative host and the fatality of the disease although for the
> typical vertebrate with serious of conservation interest, migration
> seems to be a plus. It would be great if the USDA (who
> regulates butterfly releases) would fund some work on the problem, and
> if the population biologists, epidemiologists and population geneticists
> among us would do the work.

Pat, agricultural moths are responsible for most of the the pre and 
postharvest insect feeding damage done to crops here in the USA. For
many years USDA-APHIS has funded research that looked into possible 
ways of deliberately infecting and destroying populations of some of 
these moths using releases of disease pathogens.  My understanding is 
that the success of these control methods have been marginal at best.  
For example, in one study a APHIS researcher released a granulosis virus
into peanut storage warehouses in Georgia once a week in an attempt to
control the Indian Meal Moth.  A 50% reduction in the moth population 
was the best level of control that could achieved (not nearly good 
enough for a peanut storage warehouse manager). Thus we see that
even when dealing with a CAPTIVE population of lepidopteran insects, 
we have not yet found a way to devastate them using releases of 
disease pathogens.

Now look at what NABA does http://www.naba.org/weddings.html
NABA confidently states:  " Butterflies raised by unregulated commercial 
interests may spread diseases and parasites to wild populations, with 
devastating results.

The reality is that if anyone ever found a practical way to intentionally
"devastate" either a wild or captive population of lepidopteran insects 
using releases of disease pathogens, they would become overnight 
millionaires. 

Paul Cherubini
Placerville, Calif.

 
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