Enhanced insecticidal activity of isoparaffin by ozone as an adjuvant

Chemical pesticides are used to control sanitary pests, but their negative effects human health, and the development of resistance highlight the necessity of developing new technologies. In this study, we focused on spiracle obstruction by isoparaffin as a means of pest control with low potential for resistance, and found its efficacy was strongly enhanced by ozone supplementation. When pest insects including cockroaches (Periplaneta fuliginosa), termites (Coptotermes formosanus), mosquitoes (Aedes albopictus), and stink bugs (Halyomorpha halys), were tested, mortality rates were above 60% when sprayed with a spray substance (SS) consisting of LPG, isopropyl alcohol, and isoparaffin, and 100% with ozone-supplemented spray substance (SS + O₃). Notably, death times were significantly different (t-test, p < 0.05) between treatments in cockroaches, with times of 10.5 ± 2.6 min and 1.6 ± 0.5 min (mean ± SD) for SS and SS + O₃, respectively, and mosquitoes with 13.5 ± 20.7 min and 1.6 ± 1.4 min, respectively. SEM observations indicated spiracle covering by isoparaffin supplemented with ozone, leading to suffocation. Considering the safety of ozone and isoparaffin, their combination could be environment friendly and highly effective, although the impact on biodiversity needs to be considered. Overall, ozone-supplemented isoparaffin represents a new, promising pest control agent.