Larval monitoring
1.Monitoring scope
The habitat of aquatic larvae (area and habitat type), larval density, larval species, etc. The methods include larval pipette method, larval spoon catching method and path method. Please select the corresponding monitoring method according to the monitoring purpose.
2.1 Monitoring method
2.1.1 Larval pipette method
2.1.1.1 Applicable scope
It is suitable for monitoring the density of mosquito larvae (pupae) in residential areas.
2.1.1.2 Utensils
Long straw, small eyedropper, white square plate, sampling tube, water net and so on.
2.1.1.3 Operation steps
When monitoring the density of mosquito larvae (pupae) in stagnant water in small containers, all the stagnant water shall be absorbed into a white square plate with a long straw. In addition, when monitoring the density of mosquito larvae (pupae) in stagnant water and in large containers landmark stagnant water, mosquito larvae (pupae) are caught with water netting, then turned over into a white square plate filled with water. In addition, absorb the mosquito larvae (pupae) into the numbered sampling tube with a small eyedropper. Record the location, site, container type and date. The collected mosquito larvae (pupae) are classified and counted.
2.1.1.4 Density calculation
A. Breteau Index, see Formula 4-10.
In the formula:
BI—Breteau Index
Np—Number of positive containers
Nh—Number of households surveyed
B. Container index, see(Formula 4-11)
In the formula:
CI—Container index
Np—Number of positive containers
Nc—Number of investigated containers
C. Density index, see Formula 4-12.
In the formula:
I—Larval density index
Nl—Number of larvae (pupae)
Nh—Number of households surveyed
D. Housing index, see Formula 4-13.
In the formula:(https://www.daowen.com)
HI—House index
Bh—Number of houses with larval (pupa) positive
Nh—Number of households surveyed
2.1.2 Larval spoon catching method
2.1.2.1 Applicable scope
It is suitable for monitoring mosquito larvae (pupae) in large and medium-sized water bodies.
2.1.2.2 Utensils
Long eyedropper, small eyedropper, sampling tube, 500 mL standard water spoon, etc.
2.1.2.3 Operation steps
Along the bank of large and medium-sized water bodies, select a sampling point every 10m, scoop up a spoon of water from the water body quickly, suck out the larvae (pupae) and put them into the numbered sampling tube, classify, count. In addition, record the date and place (Table 4-2).
2.1.2.4 For density calculation, see Formula 4-14.
In the formula:
I—Larval scoop index
Nl —The number of larvae (pupae) collected
Np—Number of positive spoons
2.1.3 Path method
2.1.3.1 Applicable scope
It is suitable for monitoring mosquito larvae (pupae) in small water bodies.
2.1.3.2 Utensils
Pedometer.
2.1.3.3 Operation steps
Set the step parameter according to the stride of the monitor himself, carry about the pedometer, and move forward at a uniform pace along the monitoring path. In addition, record the number of positive containers and positive small water bodies found along the way. Record the length of the path at the end.
2.1.3.4 For density calculation, see Formula 4-15.
In the formula:
I—Path index
Np—The number of positive containers and positive small water bodies
Nk—Monitoring walking distance(km)
Table 4-2 Monitoring Records of Larvae (Pupae)
Monitor: Auditor: Person in charge of monitoring: