Chapter 16 "The Rumblings of an Avalanche" Summary

As humans continue to subject the entire environment to intensive chemical spraying, weaker insects are being killed off, and stronger insects are becoming resistant to the chemicals. Earlier, pre-DDT-era chemicals had become ineffective against some insects; Carson cites several instances. Post DDT, insects began to become resistant to chemicals more quickly. Now people interested in combating disease-carrying insects are realizing the seriousness of the situation because insects carrying deadly diseases grow to be immune to chemicals. This chapter's title comes from a quotation by a scientist who says the rapidly growing list of insects that have developed resistance to chemicals may be the "early rumblings of what may become an avalanche in strength." Resistance can develop very quickly.

Many insects carry infectious diseases that are deadly to humans: mosquitoes (malaria, yellow...