What class of insecticides is most commonly used now for controlling the woolly adelgid?

What class of insecticides is most commonly used now for controlling the woolly adelgid?

• A. Organophosphates
• B. Pyrethroids
• C. Neonicotinoids
• D. Carbamates

Answer: (C)

Systemic insecticides are preferred for controlling woolly adelgid because this pest feeds inside the plant tissues, so reaching it with a surface spray is difficult. Neonicotinoids are systemic compounds taken up by the tree and moved through the vascular system, reaching the phloem where the adelgid feeds. This allows effective, residual control even if the insect is hidden inside needles or bark. Treatments such as trunk injections or soil drenches using neonicotinoids (for example, imidacloprid or dinotefuran) provide reliable control by delivering the toxin to the pest’s feeding site over time. Other classes like organophosphates, carbamates, or pyrethroids are more contact- or ingestion-based and often don’t reach the adelgid as effectively, making them less practical for this purpose.

Systemic insecticides are preferred for controlling woolly adelgid because this pest feeds inside the plant tissues, so reaching it with a surface spray is difficult. Neonicotinoids are systemic compounds taken up by the tree and moved through the vascular system, reaching the phloem where the adelgid feeds. This allows effective, residual control even if the insect is hidden inside needles or bark. Treatments such as trunk injections or soil drenches using neonicotinoids (for example, imidacloprid or dinotefuran) provide reliable control by delivering the toxin to the pest’s feeding site over time. Other classes like organophosphates, carbamates, or pyrethroids are more contact- or ingestion-based and often don’t reach the adelgid as effectively, making them less practical for this purpose.