Certified Crop Advisor Practice Exam

What is one of the causes of disease that can reduce the pest population?

1. Parasites

2. Pathogen

3. Pesticides

4. Weeds

The correct answer is: Pathogen

Pathogens are a significant cause of diseases in various organisms, including pests. When pests are infected by pathogens — such as bacteria, viruses, fungi, or nematodes — they can experience a decline in population due to altered behavior, reduced reproduction, or increased mortality. These pathogens can be part of natural biological control, where the spread of disease among pest populations helps regulate their numbers, thereby maintaining a balance in the ecosystem. In agricultural contexts, understanding the role of pathogens is essential for developing integrated pest management strategies. They can cause sudden and dramatic reductions in pest populations, making them valuable allies for farmers seeking to minimize reliance on chemical controls. This natural method underscores the importance of biodiversity, as a diverse ecosystem can promote the presence of various pathogens that can limit pest outbreaks effectively.