Anti-mite test methods and evaluation standards_China Textile Fabric,Uniform Fabric,Cotton Fabric Supplier & Manufacturer & Factory

Repellent methods

1. Put a sponge with a thickness of 10mm and a side length of about 200mm into a covered container, and pour an appropriate amount of saturated salt water (the height of the water is just enough to submerge the sponge);

2. Take 7 Petri dishes, place one Petri dish in the center of the sticky plate as the center Petri dish, and place the remaining 6 Petri dishes evenly around the center Petri dish in the shape of petals, and use the same color on the edges between each Petri dish. Width of transparent tape (acting as a bridge), and then fix the 7 petri dishes on the adhesive board;

3. In the 6 peripheral petri dishes, place the test sample and control sample at intervals. Place the sample evenly, flatly and tightly on the bottom of the petri dish, and place 0.05g of mites in the center of the sample. Feed;

4. Place (2000±200) surviving mites on the central petri dish;

5. Place the adhesive plate assembly with sample mites and feed on the sponge, cover the upper cover of the container box, and place it in a constant temperature and humidity incubator with a temperature of (25±2)°C and a humidity of ( 75±5)%;

6. After 24 hours of culture, use a dissecting microscope or stereomicroscope to observe and use appropriate methods to count the number of surviving mite adults and nymphs in the sample culture dish and the control sample culture dish.

Suppression

2. Place 3 samples and 3 control samples in 6 petri dishes respectively. Place the samples evenly, flatly and tightly on the bottom of the petri dish, and evenly disperse 0.05g of mites on the samples. Feed;

3. Put 150 surviving mites into 6 petri dishes;

4. Place 6 petri dishes on the sponge in the container box, and the distance between the petri dishes should be greater than 10mm;

5. Close the upper cover of the container box and place the petri dish in an incubator with constant temperature and humidity. The temperature is (25±2)°C and the humidity is (75±5)%;

6. After culturing for 7 days, 14 days, 28 days and 42 days as needed, use a dissecting microscope to observe and record the number of surviving mite adults and nymphs in the petri dish;

7. If the number of surviving mites in the petri dish of the control sample is less than 150, retest all samples.

Calculate and evaluate

Repellency rate (Q) and inhibition rate (Y), expressed as percentage (%):

Q=(B-T)/B×100;

Y=(B-T)/B×100;

In the formula:

B–The average number of surviving mites in the three control samples

T–the average number of surviving mites in three samples

The calculated value of the repellent rate and inhibition rate is used as the result. When the calculated value is a negative number, it is expressed as “0”; when the calculated value is >99%, it is expressed as “>99%”;

Repellency	Description of anti-mite effect
≥95%	The sample has a strong anti-mite effect
≥80%	The sample has a strong anti-mite effect
≥60%	The sample has anti-mite effect

Inhibition rate	Description of anti-mite effect
≥95%	The sample has a strong anti-mite effect
≥80%	The sample has a strong anti-mite effect
≥60%	The sample has anti-mite effect