"The chemicals, pyrethroids, are man-made versions of natural compounds in chrysanthemum flowers. ...last fall, a UC Berkeley scientist reported that pyrethroids are polluting streams in Northern California suburbs, wiping out crustaceans and insects vital to ecosystems. "
Too much of a good thing, indeed.
Pyrethroids have been popular because they are derived from natural sources: "safe enough to eat!" I remember some pitchman or other saying, as he chomped into a just-sprayed apple.(Never mind that the pitchman now resides in an asylum, under observation for paranoid homicidal episodes brought on by neurological dysfunction. Sheer coincidence.)
Seriously, it's a tricky proposition. We value the beauty and diversity of nonnative species, but we upset the natural ecological balance when we import them. So as these plants prove a little too attractive to whiteflies,
thrips , mealybugs and the lot, we turn to chemicals -- hopefully "benign" ones -- to control the bad guys, not considering that everything in nature has some connection to everything else. (Natural or not, chrysanthemum toxins were never intended to enter waterways en masse.) To further complicate matters, pyrethroids have also been a useful weapon in a more noble fight, the protection of European honeybee colonies from the predatory
varroa mites that are decimating populations of these pollinators. (Plus -- how 'bout a big shout-out to evolution?! -- the mites are developing resistance to the pyrethroids.)In this case, the state expects to regulate or even abolish the use of pyrethroids. But our addiction to nonnative species isn't going to end -- municipalities aren't going to rip out their stands of Loropetalum and Magnolia to replace them with native plant communities. And you can be sure that the companies that make pyrethroid pesticides aren't going to roll over quietly; as the Times reported, "a spokesman for CropLife America, representing pesticide manufacturers, said Thursday that the companies were unaware of California's intentions but will cooperate with its requests. He said the industry does not agree that there are toxicity problems … 'The valuable contributions that pyrethroids make through agricultural and urban uses are many and these benefits need to be considered'."
My guess is, the chemists will develop so-called "solutions," either cultivars or pesticides, engineered to be as "safe" as everyone's new favorite artificial sweetener. Of course these will open an entirely new can of worms -- assuming the worms haven't already been killed off by pesticides, herbicides, and fertilizers -- and we'll be riding this merry-go-round again all too soon.
