Associate Certified Entomologist (ACE) Practice Exam

What defines oxadiazines in term of their chemical action?

1. They inhibit chitin production.

2. They act on sodium ion channels.

3. They are hormone analogs.

4. They attract beneficial insects.

The correct answer is: They act on sodium ion channels.

Oxadiazines are a class of insecticides that exert their chemical action by acting specifically on sodium ion channels in the nervous system of insects. This mechanism disrupts the normal functioning of neuronal signaling, leading to paralysis and ultimately the death of the insect. By interfering with the flow of sodium ions, oxadiazines manipulate the electrochemical gradients essential for proper nerve impulse transmission, making them effective in pest control. The other options describe different mechanisms or characteristics of various types of insecticides or chemical agents. For instance, inhibiting chitin production is associated with certain growth regulators that interfere with the insect's ability to molt and develop properly. Hormone analogs typically mimic or interfere with natural insect hormones, affecting growth and development. Attracting beneficial insects is more related to the use of pheromones or other chemicals to enhance pest management strategies rather than a direct toxic effect on pests. Thus, the unique action of oxadiazines specifically targeting sodium ion channels distinguishes them as a potent insecticidal option.