Regulatory and Chemical method of pest control
a) Legislation for foreign quarantine to prevent the introduction new pest from abroad.
b) Legislation for domestic quarantine to prevent the spread of established pests within the country or within a particular zones/ states.
c) Legislation for notified campaigns to control insect pest.
d) Legislation to prevent the adulteration and mishandling of insecticides or other devices used for the control of pests.
Different types of chemicals are used for the control of insect pests. Insecticides can be grouped in various ways, such as; according to their chemical composition, according to their mode of entry, and according to the formulations in which they are to be applied.
Chemically, the types of insecticides are;
1. Elements such as s.p.
2. Inorganic compound such as lead, arsenate, zinc, phosphide.
3. Organic compounds.
a) Compounds or plant origin such as pyrethrum, nicotine, neem oil, fugenol.
b) Animals and mineral oils-such as fish oil, diesel oil.
c) Synthetic organic compounds- malathion, Diazinon.
d) Poisonous gases- Ethyl bromide, EIhylene dichloride(ED), Carbon Tetrachloride
According to their mode of entry insecticides can be grouped in to-
a) Stomach poison
b) Contact poison
Stomach poison: They are generally applied against insect with chewing type mouthpart. These are also mixed with food for killing higher animals like rodents, birds. Stomach poisons are applied as spray dust on baits.
Contact poison: A toxicants-which kills the insect by contact and enter into the insects through vulnerable sites, is said as contact poison which applied as dusts spray either directly to the body of the insects or the places frequented by them. This type of poison is particularly effective for the control of sucking insects.
Systemic poison: A systemic insecticide when applied to seeds, roots, stems, or leaves of plants is absorbed and translocated to various parts of the plants in amounts lethal to insects which feed on them. Most of the systemic insecticides act both as stomach & contact poisons.
Granular systemic insecticides are most effective and favourable to our farmers.
Fumigants: Poisonous gases are used as fumigants to kill insect pests of stored grain and products in ware houses, elevators, godawns etc. The toxicant enters the trachea of the insets through the spiracles in the form of gas and brings about its kill. Since all fumigants are deadly poisonous, great care is in their use. All phosphide, CH3Br.
Miscellaneous chemical having various types of action:
Now-a-days, in addition to the use of insecticides for controlling insect pests, a variety of chemicals having various types of action are also being used for controlling insect pests.
a) Chemo-sterillent: Apholate, tepa, metepa are feed to ne insects along with foods & through their physiological action, they cause sterility and ultimately the pest population declines.
b) Anti-feedants: Anti-feedants when spread on plants and mixed with foods, make them distasteful and the insect do not feed and ultimately starved death. Very recently a systemic anti-feedant called Baygon, (methyl carbamate) has been found to be an effective agent against the cotton ball weevil.
c) Alteractants: Attractants are used, when insects are to be poisoned through baits. Many attractants occur naturally either in the food or as pheromones which are secretion or released by other member of the same species, which promote aggregation, mating other types of behavior. The synthetic pheromone gyplare related to the natural compound of gypsy moth has become important in insect control work.