Material properties determining the insecticidal activity of highly divided porous materials on the pharaoh ant (Monomorium pharaonis)

摘要

BACKGROUNDHistorically, inert insecticidal powders such as diatomaceous earth were researched for pest management applications, revealing that these types of powders killed insects by desiccation. However, data on the critical material properties that affect their efficacy is sparse. The present study investigates the insecticidal effect of powdered materials on the pharaoh ant, a notorious domestic pest.RESULTSThe insecticidal activity of 24 porous materials was tested. 8 of these materials performed better than the benchmark, diatomaceous earth. Zeolite Y and carbon black II performed best, inducing 50% mortality within 40 minutes and 55 minutes respectively. Statistical analysis of 7 material properties revealed that macroporous surface area and BET specific surface area were most predictive of insecticidal activity. For zeolites and ordered mesoporous silica materials the most important parameters were respectively BET and large mesopore surface area. Finally, GC-MS analysis confirmed the adsorption of epicuticular hydrocarbons onto the zeolite powders.CONCLUSIONThis study shows clear potential for the use of environmentally friendly, inert porous materials as insecticides against the pharaoh ant and identified the key material properties influencing insecticidal activity. The GC-MS data supports the hypothesis that the mortality was caused by the removal of the protective epicuticular hydrocarbons.