(a) Insecticide: An insecticide is defined as a chemical preparation used to control insect pests.
(b) Group of insecticides: (i) Powder (ii) Liquid (iii) Granules (iv) Tablets (v) Aerosol
(c) Class of Pesticide that Kills Specific Insect Pests:

Pest killed	Pesticide	Pest killed	Pesticide
(i) Grasshoppers	Insecticide	(iii) Weaver birds Rodenticides	Avicides
(ii) Rats	Rodenticides	(iv) Eelworms Avicides	Nematicides

(d)(i) Effects of Chemical Control on the Environment: (i) Beneficial organism insects like earthworms, bees may be destroyed. (ii) Some chemicals may be toxic to man, domestic animals and plants. (iii) It may lead to pollution of the environment. (iv) It destroys aquatic life.
(ii) Effects of Cultural Control on the Environment: (i) Fire that kills harmful insects may also kill beneficial insects. (ii) Bush burning spreads within a twinkle of an eye to other places and causing excessive damage to structures, crops and animals. (iii) Fire destroys organic matter in the soil. (iv) Tillage operation destroys soil structure and causes erosion.
(d)(iii) Effects of Biological Control on the Environment: (i) Natural enemy (organism) introduced to control pest may abandon the pest and start to attack other crops in the environment originally free from attack. (ii) Predators may feed on other beneficial insects other than the ones intended to control. (iii) Newly introduced organism may cause imbalance in the ecosystem. (iv) Breeding for increased yield may alter genetic resistance of crops to pest and diseases thereby leading to increased pest/disease population in the environment.