Under the Federal Insecticide, Fungicide and Rodenticide Act (“FIFRA”), most pesticides must be registered and are subject to product labeling requirements.  FIFRA defines a “pesticide” as “any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest.” 7 U.S.C. § 136(u).  A “pest” is defined in the statute to mean: “…