Write the modes by which insects affect the crop yield.
Answer:
Crops are affected by insects in three ways:
1. Insect pests cut the parts of the plants such as root, leaf and stem affecting the plants processes such as photosynthesis leading to a decreased production of food for plant and decreased growth.
2. Insect pests attack the cell sap of a plant at various parts and feed on the nutrients of the plant resulting in poor yield of the crop.
3. Insect pests bore into fruits and stems of a plant. This leads to a decreased yield of the crop.