Physical, mechanical, and biological pest control method are given below-
Physical Pest Control Methods
1. Application of heat- superheating empty godawn to a temperature of about 10-12 hours will kill the hibernating stored grain insect pests.
2. Application of refrigeration- At 5-10oC of all eatables, including dry fruits, will kill the insects.
3. Manipulation of moisture- By raising or lowering the moisture content of other materials, unfavorable conditions are created for insect pests.
- By draining away stagnant water, mosquitoes breeding there are killed.
- Reducing the moisture content of grains below 8% would save them the insect pest.
- By soaking the logs in water over an extended period (15 days), insects are drowned.
Mechanical Pest Control Methods
1. Hand-picking: Insects can be hand-picked and destroyed if they are easily accessible to the picker, large and conspicuous, and present in large numbers in clusters. E.g., 1st and 2nd inster of jute hairy caterpillar, rice hispa, etc.
2. Using nets: The use of hand nets for collecting adult insects.
3. Beating and hooking: Knocking down the house flies with fly-flappers & the locusts with brooms is effective. On coconut trees, the rhinoceros beetles can be picked out of holes with the help of hooks.
4. Shaking: Shaking small trees or shrubs, particularly early in the morning in the cold season & collecting them in an open dish containing kerosenized water.
5. Sieving and Winnowing: These are commonly practiced against insect pests of stored grain. A no. of them are removed with this operation.
6. Mechanical exclusion: It is the device by which insects arc physically prevented from reaching crops and province.
- Screening the windows, doors & ventilators of the house to keep away house flies, mosquitoes, bugs, etc.
- Wrapping individual fruits of pomegranate, guava, and citrus paper to save them from the attack of insect pests.
- Placing four legs of an insect in vessels containing water to prevent the ant from ascending.
- Scaring birds attacking fruits & grow crops by creating noisy sound.
7. The use of mechanical trap: Cricket trap, house fly trap, the light trap for collecting & killing various types of insect pests.
The Biological Pest Control Methods
Biological control plays an essential role in insect pest control programs. The principal methods employed in biological control include-
- Collecting parasites and predators from the places of their origin and releasing them in places where they are absent.
- Collecting and staring at the host insect in such a way as to kill them but permitting the parasites to escape.
- Rearing a great no. of parasites & predators under favorable conditions releasing them whenever needed.
- Importing parasites, predators, or disease-producing organisms from foreign countries. E.g., controlling the cottony cushion of a scale insect in citrus by ladybird beetle.
Parasites and predators where are to be diploid for efficient biological control must have the ability to outnumber the host by their high reproductive rates, a greater percentage of females, short life cycle, the ability to locate the host. It should be specific inhabit and exhibit minimum super parasitism.
Some vertebrates (tadpoles, frogs, toads, snakes), protozoa, arthropods (spiders, mites, insects), micro-organisms (fungus, bacteria, viruses) act as agents of biological control. So, 110 pests in 60 countries of the world have been controlled by using biological methods.