Green and Effective Plant Essential oil Nanoemulsion for the German cockroach Control: A Novel and Environmentally Friendly Approach

The German cockroach Blattella germanica L. poses a serious threat to human health and environmental hygiene. Plant essential oils are considered suitable alternatives to chemical insecticides for controlling these common household pests. This study aimed to develop nanoemulsions of Rosmarinus officinalis L. (rosemary) and Eucalyptus globulus L. (eucalyptus) essential oils and evaluate their insecticidal activity against the German cockroach. Essential oils were extracted using a Clevenger apparatus. Nanoemulsions of rosemary, eucalyptus, and their ۱:۱ combination were prepared and characterized by particle size analysis (PSA) and transmission electron microscopy (TEM). Bioassays were conducted using the standard contact method with a ۳۰-minute exposure at concentrations of ۵%, ۷.۱%, ۱۰%, ۱۴.۱%, and ۲۰%, with acetone as the control, on male German cockroaches under laboratory conditions. Mortality was recorded after ۲۴ hours. The average particle sizes were ۸۴.۴۶ nm for eucalyptus, ۹۱.۳۳ nm for rosemary, and ۹۹.۱۶ nm for the combined nanoemulsion, all exhibiting spherical morphology. The lethal concentration values (LC۵₀ and LC۹₅) were ۴.۰۸% and ۱۰.۳۳% for eucalyptus, ۴.۷۹% and ۱۱.۳۱% for rosemary, and ۷.۰۹% and ۲۶.۵۶% for the combined nanoemulsion, respectively. The results indicate that individual nanoemulsions have higher efficacy compared to their combination, highlighting the importance of assessing both separate and combined effects to fully understand their insecticidal potential. These findings emphasize the potential of essential oil nanoemulsions as eco-friendly alternatives for managing German cockroach infestations.

کلیدواژه ها:

Blatella germanica ، Rosmarinus officinalis ، Eucalyptus globulus ، essential oil