Health Hygiene & Sanitation

Lesson 18 : Vector Management

Anti larval Measures

1. Anti-larval Measure – Environmental Modification

1. Drainage- stagnant water: urban or rural drainage of infested water.
2. Filling: by filling water collection area
3. Land leveling by transformation of impounding margins.
4. Velocity alteration in the streams and drainage
5. Solid waste management: destruction or alteration of containers – breeding places of vectors

They are as follows;

1. Stream flushing
2. Regulation of water level in reservoirs
3. Vegetation removal etc.

2. Anti-larval Measure – Chemical Control

1. Oils


• Mineral oils: oldest known mosquito control measures.


• Widely used oils are: diesel oil, fuel oil, kerosene and various fractions of crude oils.

The mechanism of killing of larvae and pupae is by forming thin layer of film on the surface of water which obstructs the air supply.

2. Paris Green:


• Paris green or copper aceto-arsenite is an emerald green, micro-crystalline powder practically insoluble in water.
• Paris green is a stomach poison.
• Surface feeding larvae like Anopheles larvae, Culex larvae and Aedes larvae feed on powder and die.
• Bottom feeding larvae of Mansonides will die, when the Paris-green applied as a special granular form.


3. Synthetic Insecticides like


• Fenthion
• Malathion
• Chlorpyrifos, and
• Abate

Are most effective. These Organo-phosphorous compounds hydrolyze quickly in water

Toxicant	Dosage in grams
Abate	56-112
Malathion	224-672
Fenthion	22-112
Cloropyrifos	11-16

3. Anti-larval Measure – Biological Control

Mosquitoes can be controlled by employing their natural enemies such as fishes, nematodes, bacteria and fungi.

1. Fish: Guppies and Gambusia
2. Fungi: Culicinomyces clavosporus, Lagenidium gigantium, Cylindrosporum etc..
3. Bacteria: Bacillus thuringienses, Bacillus spericus etc
4. Nematodes: Romanomermis culicivorax,