The italics indicate that I was quoting the article. The words you are quoting as mine are actually taken from the article I linked to.<p>DDT is so effective because it is persistent, unlike pyrethrins which degrade rapidly and need to be frequently resprayed.  As a result, it has significant environment side effects and finds its way into the food chain. My only point was that in this case, DDT might be the lesser of two evils.