The chemical analysis and insecticidal activity of Francoeuria undulata essential oil on German Cockroaches (Blattella germanica)

Cockroaches are the most resistant urban and domestic pests in the world. Hence, investigations into alternative control strategies such as the use of active compounds of plants against this insect pest are important. In this study, Francoeuria undulata (L.) plants were collected from Isfahan province, Iran, then the essential oil of aerial parts of the plant was extracted by hydro-distillation. Plant essential oil was analyzed using GC/MS. German cockroaches, Blattella germanica L. (Blattodea: Ectobiidae), were obtained from the Tehran University of Medical Sciences. Different concentrations of F. undulata essential oil were prepared in acetone, and contact and repellency tests were carried out on German cockroaches. Moreover, 40 male rats were divided into 4 groups including 1. Control and 3 treated groups that received F. undulata oil with 5%, 15%, and 30% v/v concentrations once daily for 10 days. The blood samples were collected and biochemical parameters were assayed in serum. Also, the liver tissue was isolated for histopathological examination. The major components of the essential oil were 1,8-cineole (26.02%),  α-pinene (12.51%), Camphor (8.36%), and Camphene (5.03%). The results showed that the concentrations of 5%, 15%, and 30% v/v of F. undulata oil in 60 min of exposure had 100% insecticidal activity against German cockroaches. The repellency percentage of F. undulata oil at 5% concentration was not significant compared to the control, while the concentrations of 15% and 30% of essential oil showed a significant repellent effect on German cockroaches. Furthermore, the essential oil, at 5% concentration, was non-toxic to the livers of rats. The changes in the activities of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase were also detected in the treated rats. Our findings revealed that the F. undulata essential oil has effective insecticidal activity against German cockroaches, making it a candidate for controlling this pest.