Physical and Mechanical Biological Pest Control
Mechanical Method of Pest Control
a) Hand picking: Insects can be hand-picked and destroyed, if they are easily accessible to the picker, large and conspicuous and present in large number in clusters.
E.g. 1stand 2nd inster of jute hairy caterpillar, rice hispa etc.
b) The use of hand nets for collecting the adult insects.
c) 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.
d) Shaking: Shaking small trees or shrubs particularly early in the morning in the cold season & collecting them in open dish, containing kerosenized water.
c) Sieving and Winnowing: These are commonly practiced against insect pest of stored grain. A no. of them are removed with this operation.
f) Mechanical exclusion: It is the device by which insects arc physically prevented from reaching crops and province.
1. Screening the, windows, doors & ventilator’s of house to keep away house flies, mosquitoes, bugs etc.
2. Wrapping individual fruits of pomegranate, guava and citrus paper to save them from the attack of insect pest.
3. Placing four legs of an insect in vessels containing water, so as to prevent the ant from ascending.
4. Scaring birds attacking fruits & grow crops by creating noisy sound.
g) The use of mechanical trap: Cricket trap, house fly trap, light trap for collecting
& killing various types of insect pest.
Physical method of Pest Control
a) Application of heat- super heating empty godawn to a temperature about
10-12 hours will kill the hibernating stored grain insect pests.
b) Application of refrigeration- At 5-10oC of all eatables including dry fruits will kill the insects.
c) Manipulation of moisture- By raising or lowering the moisture content of and other materials; unfavourable conditions are created for insect pest.
1. By draining away stagnant water mosquitoes breeding there in are killed.
2. Reducing the moisture content of grains below 8% would save them the insect pest.
3. By soaking the logs in water over extended period (15 days) bring insects are drowned.
Biological method of Pest Control
Biological control plays an important role in insect pest control programme. The principal methods employed in Biological control include-
a) Collecting parasites and predators from the places of their origin and releasing them in places where they are absent.
b) Collecting and staring the host insect in such a way so as to kill them but permitting the parasites to escape.
c) Rearing a great no. of parasite & predators under favourable condition releasing them whenever needed.
d) Importing parasites, predators or disease producing organisms from the foreign countries.
E.g. controlling of cottony cushion of scale insect in citrus by lady bird 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, greater percentage females, short life cycle, the ability to locate the host. It should be specific in habit and exhibit minimum super parasitism.
Some vertebrates (todpoles, frogs, toads, snalees), protozoa, arthropods (spiders, mites, insects), micro-organisms (fungus, bacteria, viruses) act as agents of biological control. So, far 110 pests in 60 countries of the world have been controlled by using biological methods.