This part of GB/T 31270 specifies the basic requirements for materials, conditions, operation, quality control, data processing, test reports, etc. for acute toxicity test of chemical pesticides on earthworm.
This part is applicable to earthworm acute toxicity test carried out for the registration of chemical pesticides. It may be used as reference for other types of pesticides.
This part is not applicable to volatile and insoluble chemical pesticides.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
clitellum
gland on the epidermis of the front of the earthworm, which is saddle-shaped or band-shaped and is usually separated from the rest of the body by color
2.2
adult worm
earthworm with clitellum in the front of the body
2.3
median lethal concentration
concentration of the test substance at which 50% of the test organisms are killed in the acute toxicity test, expressed by LC50
Note: The unit is in mg a.i./kg dry soil.
2.4
test substance
substance to be tested
2.5
chemical pesticide
pesticide made from chemical substances through artificial synthesis, some of which are synthetic bionic pesticides made through imitation, structural transformation and innovation by taking the active substances in natural products as the matrix
Synonym: synthetic organic pesticide.
[Definition 2.3.1, NY/T 1667.1-2008]
2.6
technical material
final product consisting of the active ingredients and impurities obtained during the manufacturing process, which shall not contain visible foreign substances or any additives, and if necessary, a small amount of stabilizer may be added
[Definition 2.5.1, NY/T 1667.2-2008]
2.7
formulation product
product stable in use and made from technical materials (or technical concentrate) of pesticides and auxiliaries
[Definition 2.4, NY/T 1667.2-2008]
2.8
active ingredient; a.i.
biologically active ingredient (with a specific chemical structure) in pesticide products
[Definition 3.1, NY/T 1667.2-2008]
2.9
reference substances
chemical substance or mixture used in a test to confirm or deny certain characteristics of a test substance or to judge the effectiveness of a test system
3 Test overview
Add the pesticide solution to an appropriate amount of artificial soil and mix well, and place 10 earthworms in each treatment group and cultivate them for two weeks under suitable conditions. Observe and record the toxicity symptom and number of dead earthworms at the 7d and the 14d, and then work out the median lethal concentration LC50 and 95% confidence limits of pesticides to earthworms.
