Insecticides Solved Questions With Explanations
This page includes answer key for the following post:
Table 01: MCQ on Insecticide
Table 02: Quiz on Insecticide
- Examples of inorganic compounds: Lead arsenate, sodium fluosilicate, zinc phosphide, Paris green, etc.
- Examples of organic compounds: Pyrethrum, nicotine, rotenone, etc.
- Examples of elemental compounds: Sulfur, phosphorus, thallium, mercury, etc.
- Examples of synthetic organic compounds: DDT, malathion, carbaryl, etc.
- Examples of poisonous gases: Hydrogen cyanide, ethylene dichloride, methyl bromide, phosphine, etc.
Stomach poisons are generally used against insects with chewing type of mouthparts, and under certain conditions against those with sponging, lapping or sucking mouthparts.
Systemic insecticides are applied to seeds, roots, stems or leaves of plants, and after the absorption they are translocated to various parts of the plant in amounts lethal to insects which feed on them.
Contact poisons are very common type of Insecticides. They are very efficive against the soft bodied insects. Examples of some contact poisons are as follows:
Fumigants are very effective in store houses. In a partial vacuum, longer exposure is necessary at a lower temperature than 21-37°C.
The following factors affect the effectiveness of insecticide:
- Physical properties.
- Penetration of insecticide through the cuticle.
- Weather conditions.
- Conditions in the field.
- Application of pesticides.
Oral LD50 (mg/kg) of some insecticides are as follows:
- DDT: 113.
- Monocrotophos: 21.
- Parathion: 13.
- Aldrin: 39.
- Pyrethrum: 470.
Dermal LD50 (mg/kg) of some insecticides are as follows:
- DDT: 2510.
- Monocrotophos: 112.
- Parathion: 21.
- Aldrin: 98.
- Pyrethrum: 1880.
- Endrin: 17.8.
- Mephosfolan: 14.
- Mevinphos: 6.1.
- Monocrotophos: 21
- Dicofol: 1100.
- Methoxychlor: 5000.
- Bromophos: 3750.
- MMenazon: 1200.
- Carbaryl: 4000.
- Phorate: 6.2.
- Carbocxin: 8000.
- DNOC: 600.
- Ethyl mercuric salt: 30.
- TEPP: 2.
- Carbofuran: 8.
- Schradan: 5.
Insecticide formulation is the commercial form of any insecticide.
Some formulations are as follows:
- WP or wettable powder.
- EC or Emulsifiable concentrate.
- Granules, etc.
- Nicotine sulphate: Source is tobacco.
- Pyrethrum: Source is chrysanthemum.
- Rotenone: Source is derris plant.
Endosulfan is off patent insecticide. DDT is banned in India.
Due to its highly toxic nature, it has been banned in mid-2012 in more than 80 countries. Endosulfan is banned in India.
In agriculture in India , chlorpyriphos is one of the most widely used organophosphate.