Buying toilet paper this morning, I noticed the aptly juxtaposed display of insecticides. One one side of the cardboard display were soothing pastel green Earth Options insecticide. A mixture of pyrethrins and other ingredients that, for some reason, always add up to 100%. From the looks of the rounded, green container, I think this spray coats the insect with a fuzzy green blanket allowing it to float gently to the ground, and - when it awakes, rested and less angry, it flies away into a field of butterflies and swaddled babies. I think it's endorsed by the BlogHer network too.
On the other side of the display was a more deadly formulation containing permethrin and tetramethrin. It was a black aerosol can with big angry looking bugs on it. I didn't have to read the can to know this stuff doesn't just kill bugs, it tortures them as they launch a blood-curdling death scream on contact. I think it also silences whiny children at checkout.
I happen to know names on labels - any labels - better than most anyone in the world. Long story. Permethrin and tetramethrin are pyrethrins. Synthetic forms of the naturally occuring pyrethrins. It hurts me to write the expression "naturally occuring." It's most frequently associated with harmlessness and not frequently enough associated with mercury and poop..
Anyway, in the last couple years the difference in toxicity, largely in the veterinary literature, isn't trivial to find on the different pyrethrins. Floating to the surface on Google Scholar is this search. Evaluation of the results of these studies is beyond the scope of this entry. The point is, the active substance in both cases is pretty toxic, but similar and more importantly, it's an insulting campaign based on how few people will read these two products. I'm guessing the green plastic bottle outsells the black can hands down.