Insecticidal Activity of Essential Oils and Their Synergistic Effect on Improving the Efficacy of β-Cypermethrin against Blattella germanica

Abstract

We screened the contact activity of 32 commercial essential oils (EOs) and their synergistic effect with βcypermethrin against Blattella germanica. Results showed that the most effective EOs against B. germanica were from Illicium verum, Syzygium aromaticum, and Cinnamomum camphora, with LD 50 values of less than 500 μg/insect. The most potent synergistic effects of β-cypermethrin on B. germanica were from Dysphania ambrosioides and Mentha canadensis. Both oils have a co-toxic factor of 133.33. The results of the major compound testing of the EOs showed that trans-anisaldehyde and thymol have the best insecticidal activity against B. germanica, with LD 50 values of 141.30 and 138.61 μg/insect, respectively. The compounds with the best synergistic effect on β-cypermethrin were γ-terpinene and linalool at a concentration of 0.5%. The co-toxic factors for γ-terpinene and linalool were 150 and 133.33, respectively, which were similar to the synergistic effect observed with 2% piperonyl butoxide.

Design, Synthesis, and Acaricidal/Insecticidal Activities of New Phenylpyrazole Derivatives Comprising an Imide Moiety

“…Furthermore, excessive usage of these compounds has contributed to the development of drug resistance in pests, limiting the efficacy of these pesticides. Additionally, these pesticides are often hazardous to nontarget organisms, disrupting ecosystems and harming beneficial species . Consequently, developing ecofriendly insecticides with robust activity, high selectivity, and new mechanisms is critical.…”