A pest is any living organism (plant or animal) that can cause damage to cultivated crops, farm animals and humans.

Classification of Animal Pests

Animal pests can be classified as

Insect Pest- Insect pests are animals without backbones, and they belong to the group of animals called Arthropods. Arthropods are a very large group of animals which, in addition to insects, include crabs, shrimps, millipedes, spiders, centipedes and scorpions, mites, etc.
Non-insect pest- These are animals such as vertebrates like nematodes, snails, slug’s etc.. and vertebrates like rats, squirrels, monkeys, glasscutters, birds, jackals that can cause damage to the crop.

Classification of Insect Pests

Insects can be classified based on their mouthparts, which are different in different insect groups.

Biting and Chewing Pests: These insects possess very hard biting jaws called mandibles, a second pair of jaws called maxillae, a flat upper lip called the labrum, and a lower lip known as the labium. The mandibles are used to bite off and chew parts of crops, while the maxillae are used to push the parts of the crop into the mouth. Examples are grasshoppers, locusts, beetles and crickets, armyworms, termites, leafworms, mantids, etc.
Piercing and Sucking Pests: These insects have sharp needle-like mouth parts which can pierce into stems or fruits and seeds of crops and suck juices from them. Examples are mosquitoes, aphids, mealybugs, tsetse flies, white flies, cotton stainers, capsids, etc.
Boring insects: these pests form holes in crops and live inside, feeding on the internal parts of the crop. Examples are bean beetle, stem borer, weevil, etc.

Destruction of crop tissues.
Stunted growth in crops and animals.
Weakened crop plant.
Pierced holes can be infested with harmful organisms like fungi, bacteria and viruses
Transfer of a harmful organism from an infected crop to a healthy one.
It causes ill-health to man and livestock, e.g. sleeping sickness (tsetse fly), mange (mite), and babesia (tick).

Insect pest are animals without backbones and they belong to the group of animals called A. Chordates B. Arachnids C. Arthropods D. Annelids.
Possession of mandible and maxillae are special features of A. Piercing and sucking insect B. Biting and chewing insect B. Boring insect D. Piercing and chewing insect.
These insects have sharp needle-like mouth parts which suck juices from crop plant except A. aphids, B. beetle C. mealy-bugs D. tsetse flies.
Non-insect pest include the following except A. mites B. snails C. shrimps, and slugs.
Pierced holes of crop plant can be infested with the following except A.pest B. fungi C. bacteria viruses.