Associate Certified Entomologist (ACE) Practice Exam

What is the main characteristic of physical toxicants?

1. They alter biochemical processes in insects

2. They harm insects physically

3. They are derived from plant sources

4. They primarily target the reproductive system

The correct answer is: They harm insects physically

The main characteristic of physical toxicants is that they harm insects physically. This category of toxicants operates through mechanisms that cause immediate physical damage or impairment to the insects' bodies rather than altering their biochemical processes. Physical toxicants can include substances like abrasives or desiccants, which can damage the external cuticle of insects or lead to dehydration. The physical harm leads to mortality or incapacitation, distinguishing these toxicants from chemical agents that might interfere with metabolic functions. In contrast to options that describe biochemical alterations, natural origins, and reproductive targeting, physical toxicants solely focus on the direct damage inflicted on the insect's structure and integrity. For instance, a substance that causes an insect's exoskeleton to break down would be a physical toxicant, while those that function by disrupting internal processes would not fit this definition.