Genetic Control
Genetic control involves manipulating the genetic makeup of pests to suppress or eradicate populations.
Main Approaches
|
Method |
Description |
Example |
|
1. Sterile Insect Technique (SIT) |
Large-scale rearing of target pest, sterilizing males (usually by γ-radiation or chemosterilants) and releasing them into the field → they mate with females → no offspring. |
Cochliomyia hominivorax (screw worm fly), Bactrocera dorsalis (fruit fly). |
|
2. Genetic Sexing |
Using chromosomal translocations to separate male/female lines for selective release. |
Mediterranean fruit fly programs. |
|
3. Transgenic Resistance |
Crops engineered with pest-resistant genes (Bt crops). |
Bt cotton, Bt corn. |
Chemical Control: Most commonly used method of pest management; involves using chemical insecticides to kill, repel, or inhibit pests.
Insecticide Classification (by Chemical Nature)
- Organochlorines
|
Example |
Trade Name |
Remarks |
|
DDT (Dichloro-Diphenyl-Trichloroethane) |
— |
Discovered by Paul Müller (1939); Nobel Prize 1948. First used in 1941; banned in US (1972), India (1989) due to persistence & bio-magnification. |
|
BHC / HCH (Hexa-Chloro-Cyclo-Hexane) |
— |
Effective contact poison. |
|
Endosulfan (35 EC) |
Thiodon |
Banned in India (2011) for toxicity. |
|
Dicofol (18.5 EC) |
Kelthane |
Acaricide. |
- Organophosphates
|
Example |
Trade Name |
Notes |
|
Dichlorvos (DDVP 76 EC) |
Vapona |
Fumigant & contact poison. |
|
Monocrotophos (36 SL) |
Nuvacron |
Systemic; highly toxic; banned on vegetables. |
|
Malathion (50 EC) |
Cythion |
Least toxic to mammals. |
|
Dimethoate (30 EC) |
Rogor |
Systemic. |
|
Methyl Parathion (2 % dust) |
Metacid |
Extremely toxic; banned for household use. |
|
Chlorpyriphos (20 EC) |
Dursban / Dermate |
Widely used soil insecticide. |
|
Quinolphos (25 EC) |
Ekalux |
Contact & stomach poison. |
|
Acephate (75 SP) |
Asataf |
Systemic. |
|
Phorate (10 G) |
Thimet |
Granular systemic. |
|
Ronnel |
— |
Excellent animal systemic insecticide. |
- Carbamates
|
Example |
Trade Name |
Use / Notes |
|
Carbaryl 75 WP |
Sevin |
Broad-spectrum contact insecticide. |
|
Carbofuran 3 G |
Furadan |
Systemic & nematicidal. |
|
Aldicarb 10 G |
Temik |
Highly toxic systemic. |
|
Methomyl 40 SP |
Lannate / Aprocarb |
Fast knock-down action. |
|
Propoxur |
Baygon |
Household cockroach control. |
- Insecticides of Plant Origin (Botanicals)
|
Compound |
Source |
Target / Notes |
|
Rotenone |
Roots of Derris elliptica, Lonchocarpus spp. |
Contact & respiratory poison. |
|
Pyrethrum |
Flowers of Chrysanthemum cinerariifolium |
Basis of synthetic pyrethroids. |
|
Azadirachtin |
Seeds/leaves of Azadirachta indica (Neem) |
Antifeedant, repellent, growth regulator. |
|
Nicotine |
Leaves of Nicotiana tabacum |
Acts on insect nervous system. |
- Newer Synthetic Groups
|
Group |
Example |
Trade / Features |
|
Neonicotinoids |
Imidacloprid (Confidor 17.8 SL) |
Systemic; effective against sucking pests. |
|
Ketoenols (Tetramic acid derivatives) |
Spirotetramat |
(Movento) – Bayer; systemic two-way translocation. |
|
Oxadiazine |
Indoxacarb (Avaunt 14.5 SC) |
Acts on sodium channels. |
|
Phenylpyrazole |
Fipronil (Regent 5 SC) |
Termiticide and broad-spectrum contact poison. |
|
Avermectins |
Abamectin (Vertimec) |
From Streptomyces avermitilis. |
|
Spinosyns |
Spinosad (Tracer) |
From Saccharopolyspora spinosa; stomach & contact poison. |
- Insecticides of Animal Origin
|
Compound |
Source / Note |
|
Neries Toxin |
From marine annelid Lumbrineris heteropoda (isolated 1934). |
|
Cartap Hydrochloride (Padan) |
Synthetic derivative of nereistoxin. |
Plant-Systemic Insecticides & Trade Names
|
Chemical |
Trade Name |
|
Dimethoate |
Rogor |
|
Oxydemeton-methyl |
Metasystox-R |
|
Phosphamidon |
Dimecron |
|
Monocrotophos |
Nuvacron |
|
Acephate |
Asataf |
|
Imidacloprid |
Confidor |
|
Thiamethoxam |
Actara |
|
Acetamiprid |
Pride |
Toxicity Order (Most → Least Toxic)
- Phorate > Dimethoate > Parathion > Aldicarb
- Safer (Selective) Insecticides Order
- Methoprene > Permethrin > Methoxychlor > Malathion
MRL – Maximum Residue Limit; The maximum permissible concentration of pesticide residue (or its degradation products) allowed in/on food or feed, expressed in mg kg⁻¹ body weight.
Pro-pesticides: Compounds that are inactive in their original form but become active after metabolism by plant, animal, or microorganism.
Examples: Acephate, Cartap hydrochloride.
Plant Protection Equipment
- Dusters
- Consist of a fan/blower and a hopper to distribute dry insecticide dust.
- Work on air-blast principle.
- Efficiency: Dusting can cover larger area faster but less precise than spraying.
- Sprayers
- Most common equipment for pesticide application.
- Deliver liquid formulations as droplets; classified by droplet size.
|
Spray Type |
Droplet Size (µm) |
Remarks |
|
Coarse Spray |
≥ 400 µm |
For herbicides / high-volume spraying. |
|
Fine Spray |
100 – 400 µm |
For insecticides & fungicides. |
|
Mist (ULV) |
50 – 150 µm |
Used in mist blowers & foggers. |
Microbial Control (Detailed Recap)
|
Definition |
“Control of pests by use of microorganisms (viruses, bacteria, protozoa, fungi, rickettsiae, nematodes) or their by-products.” |
|
Term given by: |
Stern & Hauns, 1949 |
|
Father of Insect Pathology: |
Agostino Bassi (proved Beauveria bassiana causes muscardine disease in silkworms) |
