True or false: Neonicotinoids are effective for controlling many scale insects as a soil drench or basal trunk application; Imidacloprid would always be a better choice than acetamiprid as it lasts longer in the plant and provides a longer window of control.

• A. True
• B. False
• C. Not always
• D. Depends on formulation

Answer: (B)

Neonicotinoids that are applied as a soil drench or basal trunk injection are meant to be taken up by the plant and reach the scale insects feeding on it, but how well they work and how long the protection lasts is not fixed. The outcome depends on the specific active ingredient, the formulation, the plant species, how the product is taken up and translocated, and the particular scale pest. Imidacloprid is often long-lasting, but acetamiprid can be more effective against some scale pests or in certain plant or soil conditions, and some formulations of either product can provide different durations of control. Because of these variables, you can’t claim that imidacloprid will always last longer or always be the better choice. Selection should be based on the pest, plant, and label-specific guidance for the formulation in use.