Why might pesticides be less effective on female German cockroaches?

The reasoning for selecting that particular answer centers around the behavior of female German cockroaches, especially during their reproductive cycle. Female German cockroaches carry their eggs in a protective case called an ootheca. When they are close to giving birth, they tend to seek out safe, hidden locations to shield themselves and their eggs from predators and environmental dangers.

This tendency to go into hiding makes it less likely for female cockroaches to come into contact with applied pesticides, thereby reducing the effectiveness of the treatment on this gender. While other factors could potentially contribute to the overall dynamics of pest control, the primary challenge with female German cockroaches directly relates to their behavior of seeking shelter during a critical time of their life cycle, rendering pesticides less effective when they are in hiding.

The other potential implications concerning resistance, lifespan, or activity levels may not capture the specific behavioral traits associated with reproductive activities that notably impact pesticide efficacy.