The Effect of Soil Moisture to the Black Beetle (Heteronychus lioderes Redtenbacher) in Rice Field(Thai)

Abstract

Study on the habitat of the black beetle Heteronychus lioderes Redtenbacher in 4 different soil moisture levels: 25, 50, 75 and 100 percentages. Completely Randomized Design (CRD) with 4 replications was designed. For choice test released 40 numbers of insect into a plastic box which contained 4 levels of soil moisture. The numbers of insect in each soil moisture were checked after released 48 hours. For no choice test factorial in CRD with 4 replications was designed. 10 numbers of insect were released in each plastic cylinder which contained soil moisture 4 levels separately. The numbers of insect in each soil moisture cylinder were checked after released 24, 48 and 72 hours according to their movement. Result of experiments showed that on choice test the insect were found 43.13, 42.50, 10.00 and 4.37 percentages in soil moisture 25, 50, 75 and 100 percentages respectively. For no choice test found that in soil moisture 25 and 50 percentages almost insects stayed around 0 - 10 centimeters below soil surface. In the soil moisture 75 and 100 percentages the insect usually moved deeper according to soil moisture increased. So the black beetle usually live in low then high moisture soil.