principle 3

3.      Control of pest activities

     Insects, rodents and birds have achieved pest status in most countries.

·      Insects

Insects cause destruction of food crops before harvesting including about 50% cereal crops. Insects attack in fields, processing plants, warehouses, supermarkets, as well as in the home where food is stored. Insects not only eat a quantity of food production but also damage it physically to create entry points for microorganisms. Food technologists use various chemicals to control pest attack on grains and dried food. They use chemicals like methyl bromide, ethylene oxide and phostoxin. Further foods are protected from insect attack by packing in insect proof containers.

A typical method to control destruction of food by insects is the use of insecticides and insect repellants to dress seeds or some other biological means.

Another programme is also employed which is used for curative control of pest attack. It includes physical, chemical and biological methods to exit insects and their eggs from already infested food. Physical method uses entolater to break the eggs of insects in wheat grains and in other dry foods. The food that is infected by eggs of insects is thrown in a revolving disc of entolater. When it revolved all the eggs will be destroyed. Eggs of insects can also be destroyed by heat disinfection in stored products. Infrared devices at 50℃ are used because insects cannot survive at this temperature and are of low cost.

·      Rodents

Major rodent contamination is discovered by the presence of burrows, dark oil and dirty stains on rodent runaways, odor of mice, filth deposits on food, as well as damaged food and other materials. Dry urine produces dark stains on food and containers. The presence of filth deposits in food processing and storage areas will alert food managers for prompt control measures. It is impossible to eradicate them completely however it can be reduced to some extent. Developing countries are mostly infected as they have poor environmental sanitization. Systematic control over mice and is practiced in most of developed countries using poison baits, rat traps and biological methods to kill mice and rats. Foods are packed properly to ensure food safety from rodents attack.

·      Birds

Birds eat a measurable quantity of crops before harvesting. In tropical regions, birds like weaverbirds, have been known to devastate whole corn crop in the field. This loss by bird invasion has traditionally been checked by installing noise-making dummies (shaped like humans or animals) at strategic point on the farm to scares birds away. Besides destruction of food crops birds also contaminate food and water. Bird screens can be erected over water supply sources and food handling areas to prevent water contamination by birds.

     Principle #4
Reduction in physical defects