Patent ID: 11969481
Assignee: ZHEJIANG ACADEMY OF AGRICULTURAL SCIENCES
Field: Pharmaceuticals (Chemistry)
Classification: CPC A  C  Y | IPC A  C

Claim 6:
7. A method for evaluating combined toxicity of thiamethoxam and tetraconazole using the device for collecting and culturing fish embryos according to claim 1, comprising the following steps:
S1: collecting embryos of fertilized fish;
S2: after collecting the embryos for 3 hours, selecting and loading divided embryos into a plurality of culture wells in an amount of 10 embryos per well, adding a pesticide solution containing thiamethoxam to a first subset of culture wells to submerge the embryos, adding a pesticide solution containing tetraconazole to a second subset of culture wells to submerge the embryos, and adding a pesticide solution containing thiamethoxam and tetraconazole to a third subset of culture wells to submerge the embryos, wherein each subset of the culture wells contains 5 to 7 different concentrations of pesticide solution, and for the pesticide solution containing both thiamethoxam and tetraconazole, a concentration ratio of the thiamethoxam and the tetraconazole ranges from 81:1 to 1:81; and an environment temperature ranges from 26° C. to 28° C. for conducting a toxicity exposure;
S3: replacing the pesticide solutions in the plurality of culture wells with fresh pesticide solutions every 24 hours, and removing dead embryos in time;
S4: finishing exposure of fish to the pesticide solutions after 96 hours, and calculating a mortality M according to formula (I) for each culture well,, M
     =
     
      
       
        (
        
         D
         /
         N
        
        )
       
       ×
       100
      
      ⁢
      %
     
    
   
   
    
     (
     I
     )
    
   
  
 

in formula (I), D is a number of dead embryos and N is a total number of embryos;
S5: calculating a 50% lethal concentration LC 50 and 95% confidence limits of the fish embryos according to the mortality M for each subset of culture wells; then calculating a sum S of biotoxicity of the pesticide solution according to formula (II),, S
     =
     
      
       
        A
        m
       
       /
       
        A
        i
       
      
      +
      
       
        B
        m
       
       /
       
        B
        i
       
      
     
    
   
   
    
     (
     II
     )
    
   
  
 

in formula (II), Am and Bm are 50% lethal concentration LC50s of the thiamethoxam and the tetraconazole respectively when used in combination, and Ai and Bi are LC50s of the thiamethoxam and the tetraconazole respectively when used alone;
S6: converting the sum S of biotoxicity of the pesticide solutions into an additive index AI according to formula (III),, AI
     =
     
      {
      
       
        
         
          
           
            1
            /
            S
           
           -
           1
          
          ,
         
        
        
         
          S
          ≤
          1
         
        
       
       
        
         
          
           1
           -
           S
          
          ,
         
        
        
         
          S
          >
          1
         
        
       
      
     
    
   
   
    
     (
     III
     )
    
   
  
 

judging the combined effect of the two thiamethoxam and the tetraconazole according to the value of the additive index AI; when AI≥25, a synergistic effect is judged, when −0.2<AI<0.25, an additive effect is judged, and when AI≤−0.2, an antagonistic effect is judged; and
wherein step S1 comprises the following steps: placing adult female brood fish and adult male brood fish into the left culture cavity and the right culture cavity of the culture cavity respectively one night in advance, with a ratio of a number of the female brood fish to a number of the male brood fish of 1:2; then pulling out the partition at dawn of a next morning, and then collecting the fish embryos 30 minutes later.