Resistance Mechanisms To Organophosphorus Insecticides In Pardosa Pseudoannulata

The present paper has first made the researches on the effects of pesticide for a long time on acetylcholinesterase (AChE), carboxylesterase (CarE) and glutathione S-transferase (GSTs) in.Pardosa pseudoannulata applying methods of biochemistry. The aim is to determine the resistance mechanisms to organophosphorus insecticides in Pardosa pseudoannulate .The main results are as follows:1. Body distributions of AChE in Pardosa pseudoannulataThe AChE in the cephalothorax had the highest specific activity of in the spiderling and the adult for the susceptible and resistant Pardosa pseudoannulata , higher in the limb and the lowest in the abdomen .The percentages of AChE specific activity in the cephalothorax were 50.49% and 42. 37% of total activity in the susceptible spiderling and the resistant spiderling of Pardosa pseudoannulata , while 43. 89% and 39. 78 % in the female , 46. 47% and 42. 38% in the male, respectively. These results are related to the distributions of nervous system and the different physiological division in different bodies of the spider.2. The relationship between AChE and the pe'sticide resistance for Pardosa pseudoannulata in the different stages of developmentThe results of AChE activities indicated that the activities of AChE in the susceptible strain were higher than the resistant strain' s in the sac egg , the spiderling and the adult for Pardosa pseudoannulata . The kinetis parameters showed that the data of Michael is constant Km was higher in the resistant strain than the susceptible strain. The ratio of Michaelis constant Km of AChE was 1.56 ,1.94 ,1.85 and 2. 78 in the sac egg , the spiderling , the female and the male for Pardosa pseudoannulata , respectively. The pesticide resistance of Par-dosa pseudoannulata to organophosphorus insecticides probably had something to do with insensitivity of AChE.3. Body distributions of CarE in Pardosa pseudoannulataThe CarE in the abdomen had the highest specific activity in the spiderling and the adult for the susceptible and the resistant Pardosa pseudoannulata, higher in the cephalothorax and the lowest in the limb . The percentages of CarE specific activity in the abdomen were 75. 21 % and 72.17 % of total activity in the susceptible and the resistant spiderling of Pardosa pseudoannulata .while 72. 67 % and 73.43% in the female, 71.02% and 71.90% in the male, respectively . These results are related to the distributions of CarE in hemolymph for spider. The mixocoel is the biggest in the abdomen , where blood is in abundance and the abdomen is the center of metabolism.4. The relationship between CarE and the pesticide resistance for Pardosa pseudoannulata in the different stages of developmentThe results of enzymic activity showed that the activities of CarE in the resistant strain were higher than the susceptible strain' s for Pardosa pseudoannulata. The ratio of CarE activities was 5. 63 , 2. 58 ,1. 84 and 1. 27 in the sac egg , the spiderling , the female and the male, respectively. The kinetis parameters indicated the data of Km was lower in the resistant strain than the susceptible strain for Pardosa pseudoannulata . The mean CarE activities were 30.023 nmoL/mg ? min and 16.500 nmoL/mg ? min in the resistant strain and the susceptible strain .respectively,which were very significant difference (P<0. 01). Frequency of individuals with high, carboxylesterase in the susceptible strain was 12.5% , while 42.5% in the resistant strain for Pardosa pseudoannulata . The test for inhibition of methamidophos to the activity of CarE indicated that CarE activity decreased correlated with the concentration of methamidophos increasing .The inhibition to CarE activity...