Shu-Jen Tuan1, Chung-Chieh Lee, Hsin Chi. 1. Department of Entomology, National Chung Hsing University, Taichung, Taiwan, Republic of China.
Abstract
BACKGROUND: The common cutworm, Spodoptera litura (Fabricus), is the most serious pest of peanuts in Taiwan. In order to devise an ecology-based and cost-effective control program, we collected life table data and consumption rates from larvae reared indoors at a constant temperature of 25°C, or outdoors at ambient temperatures during the spring and fall of 2010. A computer simulation was then used to project the population growth and damage potential of S. litura on peanuts. RESULTS: Laboratory-reared S. litura individuals produced 3548 eggs/female, whereas those reared outdoors produced 3452 and 3072 eggs/female in the spring and fall, respectively. The intrinsic rate of increase was 0.1828, 0.1308 and 0.1545 day(-1), and the net consumption rate was 194.0, 132.2 and 166.6 cm(2) larva(-1) at 25°C, in spring and fall, respectively. Population projection showed a faster growth and higher damage potential of S. litura in the fall. CONCLUSION: Population projections based on life tables and stage-specific consumption rates can reveal the stage structure and damage potential of the pest population. Our results showed that monitoring data obtained by using pheromone traps were not in concordance with the damage potential of the pest population. This approach offers a promising tool for pest management.
BACKGROUND: The common cutworm, Spodoptera litura (Fabricus), is the most serious pest of peanuts in Taiwan. In order to devise an ecology-based and cost-effective control program, we collected life table data and consumption rates from larvae reared indoors at a constant temperature of 25°C, or outdoors at ambient temperatures during the spring and fall of 2010. A computer simulation was then used to project the population growth and damage potential of S. litura on peanuts. RESULTS: Laboratory-reared S. litura individuals produced 3548 eggs/female, whereas those reared outdoors produced 3452 and 3072 eggs/female in the spring and fall, respectively. The intrinsic rate of increase was 0.1828, 0.1308 and 0.1545 day(-1), and the net consumption rate was 194.0, 132.2 and 166.6 cm(2) larva(-1) at 25°C, in spring and fall, respectively. Population projection showed a faster growth and higher damage potential of S. litura in the fall. CONCLUSION: Population projections based on life tables and stage-specific consumption rates can reveal the stage structure and damage potential of the pest population. Our results showed that monitoring data obtained by using pheromone traps were not in concordance with the damage potential of the pest population. This approach offers a promising tool for pest management.