HomeThe Palawan Scientistvol. 11 no. 1 (2019)

Insecticidal potential of Sappan (Cesalpinia sappan) seeds ethanol extract against rice weevil (Sitophilus oryzae)

Liwayway H. Acero



Insects are known not only as pests at home but in agricultural farms as well. There are insects that even destroy the quality of farm harvest and decrease its palatability and marketability. One of the very well- known insect pests is the rice weevil (Sitophilus oryzae) which damage the quality of rice grain and lowers its market value. Indigenous plant base environment friendly insecticides are now gaining popularity than commercial insecticides. There are many herbal plants in the Philippines which can be used as potential source of insecticide. One of these is Sappan (Cesalpinia sappan) which grows well along riverbanks. The aim of this study was to determine which of the following concentrations (T- control, 0%; T1, 15%; T2, 30% and T3, 45%) of Sappan seed ethanol extract (SSEE) will give the highest mortality in 1.5 h of observation. Experimental research method with four treatments and twenty samples of rice weevils were used to gather pertinent data for this study. Sappan seeds were sundried, chopped, macerated in 95% ethanol for 3 days and subjected to rotary evaporation. Data on mortality for 1.5 h with 15 minutes intervals was analyzed using Analysis of Variance and Fisher Least Significant Difference (LSD) Test as post hoc Test. Results revealed significant difference on the means of four treatments. It is imperative that rice weevils in T3 (45% of SSEE) had highest mortality in 1.5 h exposure. It implied that SSEE is a potential source of insecticide particularly for rice weevils.