What factor increases the likelihood of pesticide resistance?

The likelihood of pesticide resistance is significantly increased when there is continual use of the same pesticides or those from the same chemical class. This happens because pests that survive exposure to a particular pesticide may develop genetic resistance over time. When the same pesticide is applied repeatedly, any surviving individuals that carry resistance genes are more likely to reproduce, leading to a population of pests that can withstand the pesticide's effects.

In contrast, using a variety of pesticide classes helps to minimize the risk of resistance because it prevents pests from being continuously exposed to the same active ingredients. Applying pesticides only during peak pest seasons does not directly influence the development of resistance, as the concern is primarily about the frequency and type of pesticide used over time. Similarly, rotating application methods can contribute positively to pest management, but it is the variety of pesticides that plays a more direct role in the susceptibility or resistance of pest populations.