Citrus sinensis essential oil-based microemulsion against Plutella xylostella: development and characterization of insecticidal activity

Plutella xylostella (Linnaeus, 1758) is a pest that causes significant damage to brassica crops around the world. The use of essential oils has led to promising results in the control of P. xylostella; however, the high volatility of these essential oils has limited their use. Therefore, the inclusion of these compounds in microemulsified systems is an alternative to increase their effectiveness in the field. This study proposes the development of a microemulsion, based on Citrus sinensis (Osbeck, 1757) essential oil, for use against P. xylostella . Gas chromatography analysis confirmed that D-limonene is the most dominant compound in the essential oil (88.63%). The microemulsion showed a hydrodynamic diameter of 26.04 ± 0.57 nm and polydispersity index of 0.270 ± 0.02, confirming its monodispersity. The lethal concentration of the C. sinensis essential oil-loaded microemulsion against P. xylostella was estimated in LC 30 = 52.23 mg/mL and LC 50 = 107.79 mg/mL (via contact) and LC 30 = 48.92 mg/mL and LC 50 = 207.29 mg/mL (via ingestion). Furthermore, it reduced larval and pupal viability of P. xylostella and promoted less oviposition of P. xylostella adults than the free essential oil. Our study confirms the insecticidal potential of C. sinensis essential oil-composed microemulsion against P. xylostella and may be proposed as a sustainable alternative for the control of this pest.