Which of the following is not insecticide synergist?

Correct option is C

Correct option: (c) Nimbinol
Why (c) is correct:
· Nimbinol is a botanical insecticidal constituent (from neem), not a synergist.
· It has direct insecticidal/antifeedant activity, rather than enhancing another insecticide’s action.
❌ Why other options are incorrect (they are synergists):
· (a) Dillapiole – A known synergist that inhibits detoxifying enzymes in insects.
· (b) Sesamol – Acts as a synergist, enhancing toxicity of certain insecticides.
· (d) PBO (Piperonyl butoxide) – A classic synergist; inhibits cytochrome P450 enzymes, increasing insecticide efficacy.
�� Key Points
· Synergists themselves may have little toxicity but boost insecticide effectiveness.
· PBO is the most widely used insecticide synergist.
· Neem compounds (e.g., nimbinol) are active botanicals, not synergists.
✔️ Final Answer: Option (c)