LAUSR

BACKGROUND Aphids are significant pests of cash crops and food farm crops. Botanical insecticides are safe for aphids control, especially for organic farming. In this study, Eleocharis dulcis (Burm. f.) Trin. peel extract (EDPE), a new botanical insecticide, was investigated for its active compositions against several agricultural aphids. RESULTS The results showed that the EDPE had high insecticidal activity against Sitobion avenae Fabricius, Aphis gossypii Glover, Megoura crassicauda Mordvilko, and Acyrthosiphon pisum Harris, with the half lethal concentration (LC50 ) values of 95.92, 81.04, 140.31, and 255.73 mg/L after 48 h treatment. In the pot culture assay, the aphicidal effects of 25% EDPE soluble liquid (SL) at a concentration of 0.016% were 68.98±5.61%, 79.33±8.27%, and 88.82±3.91% after the 1st , 3rd , and 7th days of treatment, respectively. Nine compounds were identified by bioactivity-directed fractionation, which was dimethoxy-6, 6-dimethylpyranoisoflavone (1), 3-methoxy-4-hydroxylonchocarpin (2), 4-hydroxylonchocarpin (3), 4-methoxylonchocarpin (4), barbigerone (5), lonchocarpusone (6), 6a, 12a-dehydrodeguelin (7), 13-homo-13-oxa-6a,12a-dehydrodeguelin (8) and deguelin (9). Among them, 4-hydroxylonchocarpin (3) showed the highest aphidicidal activity against M. crassicauda, S. avenae, and A. pisum, with LC50 values of 97.24, 140.63, and 112.31 mg/L, respectively. CONCLUSION These data contribute to a better understanding of the aphicidal activity of EDPE and its main component, 4-hydroxylonchocarpin. This will help to develop new botanical insecticides to control aphids.