Associate Certified Entomologist (ACE) Practice Exam

What role does genetic diversity play in the development of pesticide resistance?

1. It has no effect on resistance

2. It must be low for individuals to develop resistance

3. It must be high enough to confer resistance to some individuals

4. It is solely determined by environmental factors

The correct answer is: It must be high enough to confer resistance to some individuals

Genetic diversity is a crucial factor in the development of pesticide resistance. When a population of pests is genetically diverse, there are varying traits among individuals, including some that may confer resistance to pesticides. This means that when a pesticide is applied, not all individuals will respond in the same way; some may survive due to their genetic makeup, which allows them to withstand the chemical's effects. These resistant individuals can survive, reproduce, and pass on their resistant traits to the next generation, leading to a population that is increasingly resistant over time. High genetic diversity ensures that there are enough variations within a population for some individuals to possess the necessary traits that confer resistance. If genetic diversity were low, there would be fewer chances for these resistant traits to occur, thereby making it less likely for resistance to develop in that population. Similarly, the idea that resistance could be solely determined by environmental factors overlooks the importance of genetic predisposition in the survival and reproduction of certain individuals following pesticide exposure.