Formulation Engineering of Biowastes as Green Insecticide for Successful and Safe Control of German Cockroaches (Blattella germanica (L.)) and Possible Waste Management

Abstract

This study summarizes the design for formulation engineering of waste biomass as green insecticide tablet attractants to deal with German cockroaches, Blattella germanica (L.), a serious sanitary pest affecting human health and food consumers in a hygienic and sustainable manner. With the fast development of xenotoxic resistance, the merits of botanicals including minimal costs and ecological side effects have encouraged the authors to explore the waste crude glycerol in innovative composition and combination with citronella and dillapiole essential oils, magnesium stearate (lubricant), hydroxy methyl cellulose (binder), and glucose (phagostimulant) as baits through direct compression engineering. Post-compression quality features like the optimum hardness (136.1 N), minimum friability (≤1%) with good tensile strength, dimension (40–50 mm), acceptable weight variation (≤4%), pH (7.5–7.8) and minimum moisture content (0.10–0.25%), and accelerated temperature stability were ensured as per Food and Agriculture Organization specifications. In vitro bio-efficacy experiments prescribed by World Health Organization revealed that an individual botanical tablet produced sufficient mortalities at the initial exposure (consumption) but drastically reduced with time. However, different combinations (2:2:1, 1:2:2, 3:1:1, and 0.5:2.5:2) have succeeded to achieve an almost uniform and prolonged mortality (≥75%). The novel combination was 3:1:1 with the highest knockdown (95%) and sustained activity (6 months) better than a commercial one (65%), which might be due to the amplified insecticidal synergism among karangin, pongamol, geranial, citronellal, dillapiole, mysterin, etc. We conclude that the holistic approaches used in the present study may open a new corridor of efficient utilization of green pesticidal chemistries of biowastes as bio-resources in cost-effective and eco-friendly pest protection with minimization of toxic pesticides.