The main point of the book was that the use of pesticides (specifically, at the time, DDT) had an impact on the entire ecosystem, not just the agricultural pests they were targeting. If I remember correctly, spring was "silent" because you couldn't hear the animal sounds anymore -including birds' song.
Silent Spring is interesting because most people miss the nuance of that book — a nuance that was critical to enacting smart pesticide policy — a smart policy that didn’t not include “total” bans. Here’s a doctor elaborating:
DDT was never banned internationally for use in malaria control. The idea that it was is a falsehood spread by lobbyists. Maybe you meant to post a different link, but the one that you did post is a terrible and misleading article. This article goes into some of what actually happened and the disinformation campaign:
https://en.wikipedia.org/wiki/Silent_Spring
The main point of the book was that the use of pesticides (specifically, at the time, DDT) had an impact on the entire ecosystem, not just the agricultural pests they were targeting. If I remember correctly, spring was "silent" because you couldn't hear the animal sounds anymore -including birds' song.