Laboratory evaluation of a bio-insecticide candidate from tangerine peel extracts against Trialeurodes vaporariorum (Homoptera: Aleyrodidae).

BACKGROUND: The excessive use of synthetic insecticides in modern agriculture has led to environmental contamination and the development of insect resistance. Also, the prolonged use of chemical insecticides in producing flowers and tomatoes in greenhouses has caused health problems for workers and their offspring. In this study, we analyzed the efficacy of mandarin peel ( Citrus reticulata L.) essential oil (EO) as a natural insecticide against greenhouse whitefly ( Trieurodes vaporariorum W., Homoptera: Aleyrodidae), a common pest in greenhouse production of different crops.

METHODS: Petroleum ether (PET) and n-hexane (HEX) were used as solvents to extract essential oil (EO) from tangerine peels.

RESULTS: The yield of EO was 1.59% and 2.00% (m/m) for PET and HEX, respectively. Additionally, the insect-killing power of EO was tested by checking how many greenhouse whiteflies died at different times. The results showed that PET and HEX extracts of tangerine EO effectively controlled greenhouse whiteflies. Furthermore, with both solvents, a 12.5% (v/v) application was as practical as the commercial insecticide imidacloprid. Further characterization tests with the polarimeter, FTIR, HPLC-RP, and GC-MS showed that the essential oil (EO) contained about 41% (v/v) of d- limonene and that this compound may be responsible for the observed insecticidal properties.

CONCLUSION: Therefore, tangerine peel essential oil is an excellent botanical insecticide candidate for controlling greenhouse whiteflies.