Nanoemulsion-enhanced insecticidal activity of Cymbopogon citratus and Mentha longifolia essential oils against the red flour beetle (Tribolium castaneum)

This study evaluated the insecticidal activity of essential oils (EOs) from Cymbopogon citratus and Mentha longifolia, along with their respective nanoemulsions, against Tribolium castaneum, a major pest of stored food products worldwide. GC-MS analysis of hydrodistilled EOs revealed pulegone (32.7 %) and menthone (18.5 %) as major constituents in M. longifolia, whereas C. citratus contained geranial (42.6 %) and neral (31.5 %) as dominant compounds. Nanoemulsions were prepared via ultrasonication to yield stable formulations with mean droplet sizes of 78.3 ± 3.2 nm for M. longifolia (MLNE) and 82.7 ± 4.1 nm for C. citratus (CCNE). Their insecticidal potential was assessed using contact toxicity, fumigant toxicity, and feeding deterrence bioassays. After 72 h of exposure, LC50 values for contact toxicity were 2.43 μL/cm2 (MLEO), 1.68 μL/cm2 (MLNE), 2.87 μL/cm2 (CCEO), and 2.05 μL/cm2 (CCNE). Fumigant LC50 values were 21.8, 14.3, 25.6, and 17.9 μL/L air for MLEO, MLNE, CCEO, and CCNE, respectively. MLNE demonstrated the highest toxicity, while CCNE exhibited the strongest feeding deterrent effect. Nanoemulsion formulations enhanced biological efficacy by approximately 40–45 %, likely due to improved penetration through the insect cuticle and increased surface area. These findings suggest that nanoemulsions of M. longifolia and C. citratus EOs may offer an effective, eco-friendly alternative to conventional pesticides for managing stored product pests.

Text 120671.pdf - Published Version Restricted to Repository staff only Download (2MB) Official URL or Download Paper: https://linkinghub.elsevier.com/retrieve/pii/S0022...

Actions (login required)

View Item