In the context of biological control, which statement is true?

• A. Most losses have been associated with insecticides
• B. Biological controls are never affected by pesticides
• C. Pesticides always enhance biological control
• D. Spot treatments always worsen pest control

Answer: (A)

Biological control works best when natural enemies keep pests in check. When insecticides are used, they often kill not only the target pests but also beneficial organisms like predators and parasitoids that suppress pest populations. This collateral damage weakens the biological control system and can lead to pest outbreaks or rebounds, a pattern seen in many biological control efforts. Because of that, the statement that most losses have been associated with insecticides accurately reflects how non-target effects on natural enemies undermine biological control.

Biological controls are not immune to pesticides; they can be harmed by broad-spectrum products and mis-timed applications, so saying they’re never affected isn’t correct. Pesticides do not always enhance biological control; in fact, they frequently hinder it by killing beneficial species. And spot treatments do not always worsen pest control; when used carefully and in a targeted, judicious way, they can minimize impact on natural enemies and still reduce pests.