Associate Certified Entomologist (ACE) Practice Exam

What does frass consist of?

1. Only insect excrement

2. Plant or wood fragments mixed with insect excrement

3. Only wood fragments

4. Organic debris from the environment

The correct answer is: Plant or wood fragments mixed with insect excrement

Frass is a term that specifically refers to the waste material produced by insects, particularly herbivorous insects such as caterpillars, beetles, and termites. It consists not just of insect excrement but also includes fragments of plant material, wood, or any other organic matter that the insect has consumed. This means that when insects feed on plants or wood, they break down these materials and excrete a mixture of digested material and undigested plant fibers or wood particles, which collectively define frass. This dual composition highlights the ecological role of frass as it can contribute to soil fertility, act as a food source for other organisms, and indicate the presence of specific insect activity within an environment. Understanding frass is important for pest management and ecological studies, as it can provide insights into the feeding habits and population dynamics of insect species.