Life table and population dynamics of a major pest, Leptocorisa acuta (Thunb.) (Hemiptera: Alydidae), on rice and non-rice system

The life table study of the rice bug, Leptocorisa acuta (Thunb.) on rice (R) and non-rice (NR) system were conducted in the laboratory condition. The average individual fecundity was recorded 100.999 and 59.019 eggs on R and NR system, respectively. The nymphs were observed to pass through six instars with in the duration of 24 and 22 days respectively on R and NR host. The accumulated survival of adult was 20±0.58 and 12.22±0.33% respectively on R and NR system. The demographic parameters of L. acuta on R was significantly differed (F=10.931, P< 0.005) from the NR system with higher intrinsic (rm) and finite (λ) rate of increase (0.020 and 1.020, respectively) through shorter doubling time (DT) of 34.449 days. The total generation mortality (K) of L. acuta was minimum on R system (2.7721) and maximum on NR system (3.1496), whereas the overall generation survival (GS) was in reverse order of K values (0.2 and 0.122, respectively). These differences in the demographic parameters are due to better nutritional quality in R system relative to NR system. Thus, by knowing such variations and most vulnerable stages from life table, one can make time based application of appropriate control measures against the pest population.