Page 2 - 2. Lesson_notes_-Crop_protection_management

2. Insect pests and their control

Insects which destroy or damage crop plants are called insect pests. All crops are
attacked by insect pests.

Insect pests attack the plants in three ways:
1. They cut the root, stem and leaves (Chewing insects).

2. They suck the cell sap from various parts of the plants (Sucking insects).

3. They bore into the stem and fruits (Internal feeders).
Thus, they affect overall health of the crop and reduce yield.

Preventive measures for insect pests:
• Clean cultivation

• Optimum time of sowing the crops

• Use of pest resistant varieties
• Crop rotation and multiple cropping

• Cultural practices
Control of insect pests:

By using pesticides
The chemical used to eliminate pests are called pesticides. Pesticides include

insecticides (for killing the insects), weedicides (for killing the weeds), rodenticides

(for killing rats), and fungicides (for killing the fungi).
By using natural insecticides

Like neem, nicotine, pyrethrum, etc.
Storage of grains

Most crops are harvested only once a year. Thus, they are available in plenty during

a selective time. For getting seasonal foods regularly throughout the year, they are
stored in safe storage. During storage, grains and seeds are subjected to spoilage and

wastage by various means. This loss has been estimated to be 9.3% annually.
Factors affecting stored food:

There are two main factors responsible for losses during storage. These are:

1. Biotic factors: The living organisms which influence the stored grains are
called biotic factors. These are insects, rodents (e.g., house rat, house mouse,

etc.), birds (e.g., sparrow, bulbul, crow etc.), mites and bacteria.
2. Abiotic factors: The non-living environmental factors are called abiotic factors.

These are moisture contents, humidity of air, improper temperature etc.