As bugs is the main vector, birds immediately come to mind, and of course quick googling brings significant recent bird population decline with among other reasons (chemicals, etc.) this destruction of birds and their nesting:

"Nighttime harvesting. Machines used to vacuum olives from trees at night can suck in and kill birds. This practice is used to preserve the olives' flavor, but it's a recent development that's harmful to birds."

It is kind of like getting rid of cats and after that wondering why so many rats and the plague, or the Cultural Revolution famine after that mass extermination of birds there.