Lower Toxicity of the Essential Oils With Repellent Potential Compared to Diethyltoluamide and Cypermethrin on <i>Porcellio laevis</i>.

Abstract

<h4>Objective</h4>To evaluate the acute toxicity of essential oils with repellent potential, diethyltoluamide (DEET), and cypermethrin on <i>Porcellio laevis.</i><h4>Methods</h4>Randomized preclinical trial with a factorial and controlled arrangement on three essential oils (<i>Eucalyptus globulus</i>, <i>Mentha piperita</i>, and <i>Cymbopogon citratus</i>) at 0.1%, 1%, and 10%, respectively, DEET at 10% and cypermethrin at 0.1%. Each experimental group consisted of 10 specimens, 2-3-mm-long, of <i>P. laevis</i>. Toxicity was measured by specimen mortality at 3, 24, and 48 h postexposure. Nonparametric inferential statistics were used to compare mortality between the groups. The InfoStat/E software, Version 2020, was used for analysis.<h4>Results</h4>Essential oils at concentrations of 0.1% and 1% showed similar toxicity to each other (mortality of 10%-20%) but significantly lower compared to cypermethrin and DEET (mortality of 100%). However, essential oils at 10% reached median mortality rates above 70%. Likewise, similar effects were observed at concentrations of 0.1% and 1.0% and at 24 and 48 h. The LC 50 at 24 h was 7.8% (CI 95%: 5.2-9.8), 6.1% (CI 95%: 4.9-7.4), and 9.8% (CI 95%: 8.9-10.6) for <i>E. globulus</i>, <i>M. piperita</i>, and <i>C. citratus,</i> respectively.<h4>Conclusions</h4>The evaluated essential oils showed lower acute toxicity compared to DEET and cypermethrin, depending on concentration and time.