Amartya Saha wrote:

> what the study showed is that sublethal doses of malathion can
> negatively affect leopard frog tadpoles by affecting their food chain.
> Sublethal to leopard frogs, but lethal to zooplankton.  Its a matter of
> insecticide/weedicide CONCENTRATIONS. Yes, it can be that in the field,
> such concentrations are often lower than in the U Pitt tank study.
> However there can be (and will be) instances where this concentration
> may be reached or even exceeded, depending on topography/drainage,
> rainfall and a host of other factors. 

Dr. Relyea's tank study was not representative of actual field 
conditions, hence it was not capable of demonstrating whether
or not the formulation and dosage of Malathion routinely used
in ground or aerial applications for mosquito control (~ 0.5 - 4 
ounces per acre) leaves behind residues on natural tadpole 
habitats (e.g. ponds and puddles) that are seriously lethal to 
the zooplankton upon which the tadpoles feed.

Paul Cherubini
El Dorado, Calif.

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