Abstract: The objective of this study was to clarify the effects of rifampicin (antibiotics) on the growth, development and population parameters of two color morphs (red and green) of Acyrthosiphon pisum Harris. In laboratory, four treatments were set up: control (CK), spraying rifampicin on plant surface and aphid body at the same time (Ⅰ), spraying rifampicin on aphid body (Ⅱ) and spraying rifampicin on plant surface (Ⅲ). Biological parameters (the average weight, weight difference, mean relative daily weight growth rate during the developmental period, and the mean fecundity per female) were measured. The results showed that: 1) nymph and generation durations of the two color morphs in the three rifampicin treatments were significantly longer than those of the same color type in the control (P<0.05). Adult longevity of either treatment Ⅰ or treatment Ⅲ was obviously longer than that of the same color type in the control (P<0.05), while the adult longevity of treatment Ⅱ showed no significant difference compared to the same color type in the control (P<0.05). In treatment Ⅰ, the development durations, adult longevity and generation durations of the red and green morphs were 9.46, 19.40 and 28.22, and 9.84, 18.47 and 28.29 days, respectively. 2) The average weight, weight difference and relative growth rate of the two color morphs in the three rifampicin treatments were all significantly reduced compared with the same color morph in the control (P<0.05), while the reproductive rate of each of the two color morphs was lower than that of the same color type in the control (P<0.05). 3) The net reproductive rate, mean generation duration, intrinsic rate of increase, finite rate of increase and double population time of the two color morphs in the three rifampicin treatments were significantly different from the same color morph in the control (P<0.05). However, all the population parameters were not significant between the two color morphs (P>0.05).

Key words: soil carbon cycling, plant photosynthesis, stable isotope tracing technique, elevated atmospheric CO₂ concentration