Zhong GuoHua

THE BIOLOGICAL ACT'IVITIES OF YELLOW AZALEA, RHODODENDRON MOLLE G. DON AGAINST THE VEGETABLE LEAFMINER, LIRIOMYZA SATIVAE (DIPTERA: AGROMYZIDAE) *

Abstract  The results of laboratory and greenhouse bioassays indicated that Rhodojaponin‐ III (Abbr. R‐ 1) and extracts of flowers from Rhododendron molle G. Don possessed signficant feeding inhibition and insectcidal properties against the larvae and adults of Liromyzia sativae. Treated with 500 mg/L R‐ III 1 000 mg/L molosul‐tap, and 10 000 mg/L methanol(MeOH) ethyl acetate (EtOAc), CH2Cl2, methanol‐water (MeOH‐H2O) extracts the rates of feeding inhibition were 77. 34 % 74.30 % 82.15 % 77.50 % 67. 33 % 62.85 % against the 2nd instar larvae, and were 67.66% 55.21 % 49.72% 54.26% 46.81 % 38.53% against the 3rd instar larvae, respectively;LC50 values against the 2nd instar larvae were 208.65, 166.05, 2.74 ± 103,766.72, 5.95 ± 103, 1.85 ± 103mg/L, and against 3rd larvae were 300.62, 256.00, 4.33 ±103, 1.03 ± 103,9.79 ± 103, and 2.62± 103mg/L, respectively. Against the adults, LC50 values of R‐III EtOAc extract and molosultap were 159.07.723.87 and 134.55mgL respectively after treatment for 24 h.