| Summary: | 碩士 === 國立中興大學 === 昆蟲學系 === 87 === The intrinsic rate of increase (r), the net reproduction rate (R0), and the mean generation time (T) for Lipaphis erysimi (Kalt.) are 0.35 day-1, 61.3 offspring / female and 11.6 days at 26℃, respectively. The population growth of L. erysimi and it’s effect on the growth of common kale (Brassica alboglabra Bail var. acephala DC.) are observed by rearing L. erysimi on three different growth stages of common kale plants under three conditions. Using the result from life table of L. erysimi at 26 ℃ to simulate the population growth, the simulated population growth is faster than the observed ones in growth chamber. However, the population growth of L. erysimi in the field is faster than the simulated one. The results also showed that the population growth of L. erysimi on common kale of different stages is similar in growth chamber at 14℃, 26℃ and in the field. There is no significant difference between 14℃ and 26℃, too. But the population grows faster in the field than in growth chamber. The growth of common kale is inhibited and the plants have higher mortality in growth chamber. The growth of common kale in the field is not inhibited before the dispersal of aphids.
The effect of dispersal on the population growth of L. erysimi was studied in the screen house experiment. The population growth in screen house is faster than that of simulated one at the beginning period. After a few days, because of the mortality due to dispersal, the population growth becomes slower than the simulated one. The results also showed that the shorter the row distance, the lower the mortality due to dispersal.
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