The next big scare? Why would someone bring to the US a colony of them (or a number big enough to make one)? Anyway, I can't stop thinking on P.K.Dick's Meddl

The next big scare? Why would someone bring to the US a colony of them (or a number big enough to make one)? Anyway, I can't stop thinking on P.K.Dick's Meddler, but with hornets instead of blue butterflies. Try to avoid bringing them from the future.