Development and Optimization of a Nanoparticle-Based Imidacloprid Insecticide for Effective Control of Blattella germanica.

Background: The German cockroach (Blattella germanica) is a pest with a global distribution that has adapted to live in human environments. Blattella germanica threatens human health by producing asthma-inducing allergens, carrying pathogenic/antibiotic-resistant microbes, and contributing to unhealthy indoor environments. Effective application of insecticides can play an important role in cockroach control programs. The purpose of this research was to develop and optimize a nanoparticle-based imidacloprid insecticide and evaluate its effectiveness against the German cockroach.

Methods: A bioassay was conducted to determine the LC₅₀ and LC₉₀ of imidacloprid technical against adult German cockroaches. The appropriate initial concentration of 3mg/m² was then utilized in the synthesis of nanoencapsulated imidacloprid via the ionic gelation method. The average particle size was determined using Dynamic Light Scattering (DLS) and the dried nanoparticles were analyzed using a Scanning Electron Microscope (SEM). The LC₅₀ and LC₉₀ values of Nano-imidacloprid were then compared with the technical grade of the insecticide.

Results: A comparison of the bioassay results for nanoencapsulated and imidacloprid technical revealed a superior insecticidal effect of the nanoencapsulated imidacloprid against the German cockroach. The LC₅₀ value for the nanoencapsulated imidacloprid decreased from 4.656 to 3.081 mg/m² and the LC₉₀ value decreased from 8.381 to 4.486 mg/m² when compared to imidacloprid technical.

Conclusion: The use of nanotechnology in insecticides can lead to increased efficacy and reduced consumption. This is because the smaller particle size of nanomaterials allows for better penetration and targeted delivery to pest organisms, reducing the overall amount needed for control.