Effects of constant temperatures on development, survival and reproductionof apterous Lipaphis erysimi (Homoptera : Aphididae) on cabbage

The development, survival, and reproduction of the turnip aphid, Lipaphis e rysimi (Kaltenbach) (Homoptera: Aphididae), were determined at eight consta nt temperatures (5, 10, 15, 20, 25, 27, 30 and 35 degrees C) on cabbage, Br assica oleracea var. capitata L. var 'Grand Slam' in the laboratory. Develo pment and reproduction oft. erysimi were significantly different under diff erent temperatures. No nymphs developed to fourth instars, and no adults pr oduced any nymphs at 5 and 35 degrees C. Nymphal development to the adult s tage required 19.4 d at 10 degrees C, 4.9 d at 27 degrees C and 5.0 d at 30 degrees C. The longevity of apterous adults was greatest (25.3 d) at 15 de grees C, but it was significantly reduced at higher temperatures. Among the life table parameters, intrinsic rate of natural increase (r(m)) and finit e rate of increase (lambda) were maximal at 27 degrees C and then declined at 30 degrees C. Generation time (T) and doubling time (DT) decreased to th e shortest time at 27 degrees C, and then increased at 30 degrees C. The ne t reproduction rate (R-o) values were 89.32 and 83.58 nymphs per female at 20 and 25 degrees C, respectively. The greatest r(m) (0.438) was obtained a t 27 degrees C, followed by 0.3339, 0.3454, and 0.3620 at 20, 30, and 25 de grees C, respectively, 0.1621 at 15 degrees C, and the lowest, 0.1155 at 10 degrees C. L. erysimi population could be doubled in as short as1.6 d at 2 7 degrees C compared with 6.0 d at 10 degrees C.