Question

How do insects, pests attack the plant and affect it?

Answer 1

Insects and pests can attack the plants mainly in three ways which include:
(i) They can directly attack and cut the root, stem, and leaf of the plants.
(ii) They can suck on the cell-sap from various parts of the whole plant.
(iii) They sometimes even bore into the stem and fruits of the plant. This way they can affect the health of the crop and reduce yields.

Complete answer:
Insect damage in the plants can vary in ranges from reduced plant vigour to plant death and heavy crop losses that occur. Insects injury plants by chewing foliages, sucking juices, laying eggs and transmitting diseases.
Insects can be held responsible for two major types of damage to the growing crops. The first kind is when a direct question is done to the plants by the act of feeding by insects. In this, these insects eat leaves or burrows into the stems, fruits, or roots. There are around a hundred pest species of such type that are present and can affect the plants. They can affect both in larvae and adults, among orthopterans, homopterans, heteropterans, coleopterans, lepidopterans, and dipterans
The second type of damage is a kind of indirect damage as in this the insect itself does little or no harm but instead transmits a bacterial, viral, or fungal infection straightaway into a crop. Some of the examples include the viral diseases of sugar beets and potatoes which are carried from plant to plant by aphids.

Note: When the plants come in contact with insects pests then we can call it the victim plant. A victim is a crop or food source that is affected by insects and pests. We call these insects ‘pests’ because they are the ones capable of significantly reducing crop yields, which can later cause a lot of problems for agriculture that can even be threatening food security.