What measures must be taken to prevent spoilage and insectattack of harvested grains.

To prevent spoilage and insect attack of harvested grains, the following measures should be taken:

1. Proper Drying: After harvesting, grains should be properly dried before storage. This reduces the moisture content, making it less attractive to insects and less likely to spoil.

2. Clean Storage: The storage area should be thoroughly cleaned to remove any insects or their eggs before storing the new crop.

3. Use of Insecticides: If the infestation is high, appropriate insecticides can be used. However, they should be used judiciously and in recommended quantities to avoid any harmful effects.

4. Regular Inspection: Stored grains should be regularly inspected for any signs of spoilage or insect attack. Early detection can prevent the spread to the entire stock.

5. Proper Storage Conditions: Grains should be stored in a cool and dry place. High temperature and humidity can lead to the growth of moulds and increase insect activity.

6. Use of Hermetic Bags: These are airtight bags that can protect the grains from insects and pests.

7. Fumigation: In case of severe infestation, fumigation of the storage area can be done.

8. Rotation of Stock: Older stocks should be used first. This prevents the grains from being stored for too long, which can lead to spoilage.

9. Use of Traditional Methods: Certain traditional methods like the use of neem leaves, ash, etc. can also help in preventing insect attack.

10. Proper Handling: Rough handling can lead to cracks in the grains which can attract insects. Therefore, proper handling is necessary.

By following these steps, one can significantly reduce the chances of spoilage and insect attack on harvested grains.