This research aimed to discover the biological activity of Heart-leaved moonseed extract against M persicae and to figure out the most etlective concentration in controlling M. persicae. This was experimental research using a Randomized Block Design (RBD) consisting of 1 factor with 6 levels and repeated 5 times so that consisting of 30 experimental units. The treatments given were: BO 0%, B 1
0.25%, B2 0.5%, B3 I% B4 2% and B5 4%. The concentration of 0.25% was obtained by dissolving 0.25 grams of Heart-leaved moonseed stem extract with 100 ml of distilled water. The other concentrations were acquired by following the same procedure. Heart-leaved moonseed stems with a size of 1-2 cm were dried and mashed and then soaked using methanol for 2X24 hours with a ratio of 1:10 and then 6 concentrations were made as to the testing of vegetab.le pesticides on
aphid nymphs. Research variables observed were efficacy, mortality, mortality rate, and LC50. The results indicated that there was a correlation between mortality and the concentration given; the higher the concentration given, the higher the mortality value. The dose of 1.365%, with an upper limit of 1.073% and a lower limit of 1.774%, was a dose thought to kill half of the M.persicae population. The
dead Mpersicae would turn brown and shrivel up. There were mosaic viruses characterized by the occunence of chlorosis.