Comparative Study on the Resistance of Beta-Cypermethrin Nanoemulsion and Conventional Emulsion in Blattella germanica

Objective: This study aimed to compare the resistance rates of Blattella germanica to beta-cypermethrin nanoemulsion and conventional emulsion and establish reference values via biochemical detection for conventional emulsion. Methods: We conducted experiments using subcultured Blattella germanica and applied the micro-drop method for treatment. Subsequently, the activity of metabolic enzymes was measured using spectrophotometry. Profile analysis was employed to study the resistance rates of beta-cypermethrin nanoemulsion and beta-cypermethrin emulsion. Results: The regression equation for the relationship between generation and resistance factor in Blattella germanica treated with beta-cypermethrin nanoemulsion was as follows: y(1) = 0.091x(1) + 0.991, with an r-value of 0.990 (F = 95.184, p = 0.01 < 0.05). Similarly, the regression equation for Blattella germanica treated with emulsion was y(2) = 0.376x(2) + 1.051, with an r-value of 0.993 (F = 141.094, p = 0.007 < 0.05). The comparison of slopes between these two regression equations yielded an F-value of 8.61, indicating a significant difference (p = 0.001 < 0.05). Conclusion: Our findings suggest that the resistance factor in Blattella germanica treated with beta-cypermethrin nanoemulsion differs from that treated with beta-cypermethrin emulsion. Specifically, the resistance factor of beta-cypermethrin nanoemulsion increased at a slower rate compared to beta-cypermethrin emulsion.