Definition and types of Repellents
Definition of Repellents
The chemical which causes insect to make oriented movements away from its source is known as repellents. Repellents usually substances with a strong smell, act in the opposite way by keeping pest away. Dethier (1947) has defined, repellents as those substance whose stimuli elicit avoiding reaction. Repellents are chemicals, prevent insect damage to plants or animal by rendering them unattractive, unpalatable or offensive.
Types of repellents
There are two group of repellents which are
A. Physical repellents
Physical repellents are water, dust, waxes, granular, oils, sound, smoke, heat, air current, movement of fan etc.
B. Chemical repellents
Oil of citronella and oil of camphor are widely used as mosquito repellents. Spraying of Bordeaux mixture comprising cupper sulphate and lime repels leaf hopper, fruit fly and some chewing insects. Dimethyl phthalate, βnaphthol, Benzyl benzoate etc. are used against mites. Diethyl toluidine provides protection against mosquitoes, ticks and fleas. Phenol is extremely used to drive bees from the hive. Besides, benzaldehyde, propionic anhydride, acetic acid etc. are also used to drive honey bees. Other cosmetically acceptable repellents in the form of cream, foam, lotions etc. are used to drive mosquitoes.
