As the climate changes, and particularly as temperatures rise, insects will become one of the main causes of crop loss in the world's tropical countries. That is what a study in the United States indicates.

According to the researchers' calculations, for every degree of rise in global temperature, insects will destroy at least 10-25% more wheat, rice and maize.

Warmth will make these crop pests stronger and increase how much they eat. It will also increase their breeding.

That will affect the world's main food grains, in the view of Curtis Deutsch, a co-author of the paper.

"At present the amount insects eat is equivalent to 12 loaves of bread. But if overall temperatures keep rising at this rate to the end of this century, the insects will eat two more loaves," researchers at the University of Washington told the BBC.

Professor Deutsch, Joshua Tewksbury and their colleagues carried out the study in a fully global context, choosing the three main food grains eaten by people around the world.

In the study, published in the journal Science, they used data collected from around the world to make a mathematical calculation, which indicates that insects do more damage to crops as temperatures rise.

The team analysed data on 38 species of harmful insects through their mathematical model, to see how temperature affects the growth of these insects as well as their impact on food grains. The exercise was carried out to understand future crop losses.

Climate change alone has been found to cause crop losses of 5 per cent for each degree of temperature rise. When the effect of insects is added, that loss will reach 50%, according to Professor Tewksbury of the University of Colorado Boulder in the United States.

Source: BBC Bangla. First published in Bengali on The Agro News.