[Acute toxicity of DDT and its effects on life table demography of Moina macrocopa].

The 48 h LC50 of DDT to Moina macrocopa was determined by acute toxicity test, and the effects of different concentrations (1, 8, 16, 24, 32 and 40 microg x L(-1)) of DDT on the life table demography of M. macrocopa was studied by life table demography. The results showed that the 48 h LC50 of DDT to M. macrocopa was 324 microg x L(-1). 1-40 microg x L(-1) of DDT had no significant effects on the life expectancy at birth, generation time, net reproductive rate, and gross productive rate of M. macrocopa (P > 0.05), but significantly affected the intrinsic rate of population increase (rm) (P < 0.05). The rm of M. macrocopa increased markedly at 8, 16 and 40 microg x L(-1) of DDT, compared with the blank control, indicating that when the life table demography of M. macrocopa was used to monitor the ecological effects of sublethal concentrations of DDT, rm could be a sensitive indicator.