ON GROWTH AND PRODUCTION OF SIMOCEPHALUS VETULOIDES SARS

The growth and reproduction of the Simocephalus vetuloides Sars at 12-23℃, 20℃ and 30℃ has been studied in the laboratory. The growth rate varies with the number of instars. Most of growth curves show an initial high rate in the juveniles, an intermediate rate in the young adults and a low rate in the older adults. The total life span on a decrescent basis varies with the increasing of temperature.This species produces about 205. 12 yaungs in 45.80± 20.54 days of its life span at 12--23℃, 205-21 youngs in 50.20±9.86 days of its life span at 20℃ and 97.79 yaungs in 29.20±2.15 days of its life span at 30℃. This species has a higher rate of young production (a=11.96,10.22) at 12-23℃ and 20℃ than at 30℃ (a=8.21). The results of these experiments show a appropriate temperature in 15-20℃.The culture of S'.vetuloides are divided into 2 groups at 20℃. one is in original medium, and the another is in new medium by changing every 5 days. Rich food can promote it's life Span. The sum of young and the sum of broods are increased,and interval of praduations are shortened.