Formulation of Fipronil based Gel Bait from In-House Raw Materials for Control of Cockroaches: A case study at Chemplex AgroPharma.

AbstractCockroach infestations pose significant public health and hygiene challenges in food-handling facilities. This study evaluated the efficacy of an internally prepared insecticidal gel bait containing 1% (w/w) fipronil active ingredient. The formulation was applied to infested sites, and cockroach mortality and infestation levels were monitored over- six weeks. Fipronil residues in dead cockroaches were quantified using Chromatographic analysis to confirm ingestion and exposure. Poisson regression analysis revealed a statistically significant effect of exposure time on mortality (p < 0.001), with each additional week of bait exposure increasing expected mortality by approximately 4.3%. No mortality was observed prior to treatment, and infestation levels declined progressively following bait application. Detectable and quantifiable fipronil residues were confirmed in dead cockroaches (0.06%), demonstrating bait ingestion and active ingredient uptake. These findings support the alternative hypotheses that the formulated fipronil bait effectively reduces cockroach infestations and that fipronil residues are present in deceased insects. Overall, the study demonstrates that the in-house formulated gel bait is an effective and practical tool for managing cockroach infestations in food-handling environments. Keywords Fipronil based gel bait, In-house formulation, HPLC analysis, German cockroach, Institutional pest management