Material properties determining insecticidal activity of activated carbon on the pharaoh ant (Monomorium pharaonis)

Abstract

Non-toxic and environmentally friendly insecticidal powders have grown in popularity as pest control products to substitute traditional pesticide-based methods. The pharaoh ant is an ideal test species for insecticidal dusts and it is an indoor pest, mostly found in heated buildings where it can pose severe risks because of its ability to destroy electrical equipment and transfer diseases in hospitals. The use of commercially available activated carbon and carbon black materials as insecticidal dust is of great interest, since these types of materials proved effective in previous research and they have been little researched in the past. In the present study, we compared the effectiveness of 11 different carbon materials to reveal the key material properties defining the insecticidal action. All of the materials, with the exception of Printex U, performed better than the benchmark diatomaceous earth, which is presently the most widely used insecticidal dust. The shortest median survival time, 25 min, was observed upon exposure to activated carbon powder, which was significantly shorter than the 95 min observed for diatomaceous earth. Model selection revealed that particle size was the most important parameter determining insecticidal activity for activated carbon materials. Overall, our findings highlight the potential for the use of carbon materials as insecticidal agents, not just for the control of the pharaoh ant, but potentially also to control other domestic or agricultural pests in confined spaces, such as stored grain pests or bed bugs.