Effect of Temperature on Development, Survivorship, and Reproduction of Rice Root Aphid (Homoptera: Aphididae)

Abstract

Development, survivorship, and reproduction of rice root aphid, Rhopalosiphum rufiabdominalis (Sasaki), were measured at 10, 15, 20, 25, 30, and 35°C. The developmental time from 1st instar to adult varied from 20.7 d at l0°C to 4.4 d at 30°C. The lower-temperature developmental thresholds for 1st through 4th instars and total immature stages were estimated at 7.0, 6.2, 6.3, 5.1, and 6.1°C, respectively. A modified Logan model was used to describe the relationship between developmental rate and temperature. The survival of total immature stages varied from 52.7 to 90.23% within the temperature range of 10–30°C. At 35°C, nymphs did not develop beyond the 4th instar. The average longevity of adults ranged from 29.73 d at 10°C to 9.42 d at 30°C. The mean number of nymphs produced by R. rufiabdominalis varied from 63.32 at 20°C to 31.88 at 30°C. Life table parameters also were determined at 5 constant temperatures (10–30°C). The population reared at 25°C had the highest intrinsic rate of increase ( r m) (0.432), the shortest population doubling time (1.61 d) and shorter mean generation time (8.7 d) compared with populations reared at other temperatures. The highest net reproduction rate ( Ro ) was recorded at 20°C (57.23). The optimum range of temperatures for R. rufiabdominalis population growth was 20–25°C.