Received: 15-11-2013 / Accepted: 26-12-2013
The Small Brown Planthopper Laodelphax striatellus Fallen (SBPH) is a key insect pest of rice in Northern provinces. In addition to direct damage to development and productivity of rice, SBPH is a vector of viral diseases of rice. The study was conducted at the relative humidity of 85% and two temperatures, 250C and 300C with the food being 15-day old rice seedlings of variety Bacthom No 7. The results showed that at 250C and 300C SBPH’s life cycle was relatively short with 28.5 days and 24 days; the oviposition time with 9 days and 7 days; and average number of eggs per female 154.07 and 104.63, respectively. At 250C and 85% RH, SBPH’s the natural intrinsic rate (r) was relatively high (0.1194); Net reproductive rate (R0) was 52.07 and time for double population (DT) was 5.81 days. At 300C and 85% RH, SBPH’s the natural intrinsic rate (r) was relatively high (0.1294); Net reproductive rate (R0) was 32.91 and time for double population (DT) was 5.36 days.