Comparative Efficacy of Fipronil and Permethrin Powder Baits on Periplaneta americana Under Laboratory Conditions

Abstract

Powder bait formulations for cockroach management remain underexplored, despite their potential to provide safer and more targeted control compared to liquid insecticides. This study investigated the comparative effects of fipronil and permethrin powder baits against Periplaneta americana under controlled laboratory conditions. Adult cockroaches were collected from Yaba, Lagos, Nigeria, acclimatized at 28 ± 2 °C and 75 ± 5% relative humidity, and exposed to powder baits at three dosages (1.0 g, 1.5g, and 2.0 g), with control (0 g) replicated four times. Mortality was recorded at three-hour intervals over 24 hours. Probit regression estimated median lethal time (LT₅₀), while one-way ANOVAcompared means across bait types and concentrations at p < 0.05. Fipronil elicited a gradual, sustained toxic effect, with LT₅₀ values ranging from 10.64 to 10.96 hours, supporting its potential for long-term colony suppression through secondary transfer. Permethrin induced rapid knockdown, particularly at 1.5g, where mortality peaked at 80% within 12 hours. Statistical analysis revealed no significant differences between bait types (P= 0.10) or concentrations (P= 0.35), though all treated groups differed significantly from the control. Overall, permethrin showed acute toxicity suitable for immediate suppression, while fipronil produced consistent mortality with slower onset, making it valuable for sustained control. Incorporating both powder bait formulations into integrated pest management programs may enhance efficacy, reduce reliance on hazardous liquid sprays, and minimize risks to non-target organisms.