Mention three different ways in which insect pests can attack the crop plant.

The ways by which the insects attack the crop plants are:

(i) The chewing insects destroy all sorts of crop plants. They cut the root, stem and leaf of the crop plants by the help of their chewing mouthparts.

(ii) Sucking insects suck the cell sap from various parts of the plant. They make fine punctures in the skin of plants with their needle - like, hollow beaks, suck the sap and leave the crop damaged.

(iii) The internal feeders live inside the plant parts. They make holes in the developing grains and eat it completely or partially.