Toxicity of essential oils from plants towards Tyrophagus putrescentiae (Schrank) and Suidasia pontifica Oudemans (Acari: Astigmata)

The fumigant activity of essential oils from Cinnamomum zeylanicum, Eugenia uniflora, Eugenia uvalha, Melaleuca leucadendra, Piper marginatum, and Schinus terebinthifolius was evaluated for control of the mites Tyrophagus putrescentiae (Schrank) and Suidasia pontifica Oudemans. The average mortality, after 24 h of exposure to oil of C. zeylanicum at the highest concentration tested (50 μL/L of air), was 97.7 and 92.9% for T. putrescentiae and S. pontifica, respectively. Mortality of the two species at the same concentration of S. terebinthifolius was 86.7 and 100%, respectively. As measured by LC 50, the most toxic oil for T. putrescentiae was eugenol (0.23 μL/L air) followed by C. zeylanicum (0.82 μL/L air) , E. uvalha (3.71 μL/L air), and S. terebinthifolius (8.25 μL/L air). The most toxic oil for S. pontifica was eugenol (0.57 μL/L air) followed by C. zeylanicum (1.75 μL/L air), S. terebinthifolius (4.87 μL/L air), and E. uvalha (11.09 μL/L air). Both mite species responded faster to S. terebinthifolius than to the other essential oils. ► Cinnamomum zeylanicum, S. terebinthifolius and E. uvalha oils were toxic to the mites T. putrescentiae and S. pontifica. ► Both mite species showed a quick lethal response to S. terebinthifolius essential oil. ► Essential oils were more toxic than their major components to the mite species.