Associate Certified Entomologist (ACE) Practice Exam

How do pitfall traps function to capture insects?

1. By using light to attract them

2. With the assistance of gravity and a catch basin

3. By emitting pheromones

4. Through chemical deterrents

The correct answer is: With the assistance of gravity and a catch basin

Pitfall traps function effectively by employing gravity as their primary method of capturing insects. These traps are typically designed as containers, such as jars or buckets, that are buried in the ground so that the rim is level with the soil. When insects move along the surface, they may fall into the trap due to its vertical walls that are difficult for them to escape. The catch basin at the bottom collects the insects, preventing them from climbing out. This method relies purely on the physical interaction of the insect with the trap's structure rather than attracting them through light, chemical signals, or pheromones. As a result, the use of gravity ensures that once insects enter the trap, they cannot escape, leading to successful capture for sampling or research purposes. This makes pitfall traps a straightforward yet effective tool in entomological studies, particularly for monitoring ground-dwelling insects.