One caution: pesticides like DDT are more effective at first, before the local population is selected for resistance. The big anti-malaria campaigns in the 1950s tended to report resistance being a significant impediment with a decade: http://gladwell.com/the-mosquito-killer/
It would be curious to know whether the resistance was just to the killing effect of the mosquito or if it still continued to repel and stop them from biting.
One of the huge advantages of DDT over later pesticides is that it stopped them from biting, the other ones keep them biting until they're dead.
I'm of the mindset that DDT should have remained legal as a residential application to the house (screens, nets, walls). The quantities applied here were much smaller than for agricultural use, and there has never been a study that convincingly showed harm to mammals. (Even the bird egg shell thinning theory was tenuous at best, TEL in leaded fuel could have had the same effect in the targeted time period)
> I'm of the mindset that DDT should have remained legal as a residential application to the house (screens, nets, walls).
The international anti-DDT treaty allows countries to take this route, and as a result DDT is still legal for residential use in some countries where malaria is endemic. The US opted for a total ban, though.
