2,4D is an herbicide, not and insecticide. Article suspect.
I agree the term does not apply to 2,4 D, but this sentence shows the actual chemical genres reviewed:
“The 19 candidate pesticides not previously linked to prostate cancer included 10 herbicides, several fungicides and insecticides, and a soil fumigant.”
They are using a strange definition.
Pesticide incudes both herbicides and insecticides.