As temperatures rise, so do insects' appetites for corn, rice and wheat

For each degree increase, the hungrier pests may do 10 to 25 percent more damage to the crops
BY SUSAN MILIUS 12:24PM, AUGUST 31, 2018

With temperatures creeping up as the climate warms, those very hungry caterpillars could get even hungrier, and more abundant. Crop losses to pests may grow.

Insects will be “eating more of our lunch,” says Curtis Deutsch of the University of Washington in Seattle. Based on how heat revs up insect metabolism and reproduction, he and his colleagues estimate that each degree Celsius of warming temperatures means an extra 10 to 25 percent of damage to wheat, maize and rice. Their prediction appears in the Aug. 31 Science.

Insects already munch their way through 8 percent of the world’s maize and wheat each year, and damage 14 percent of rice, Deutsch says. If Earth’s average global temperature rises just 2 degrees above preindustrial levels, annual crop losses could reach about 10 percent for maize, 12 percent for wheat and 17 percent for rice. That’s a total loss of about 213 million tons for the three grains combined.

Unlike mammals and birds, insects heat up or chill as their environment does. As an insect warms, its metabolism speeds up, too. The faster it burns energy, the more ravenously the insect feeds and the sooner it reproduces. The speed-up rates aren’t hugely different across kinds of insects, Deutsch says. So he and his colleagues developed a mathematical simulation of how much insects as a whole would rev up, reproduce and ravage grains in warmer times.

More:
https://www.sciencenews.org/article/temperatures-insects-appetites-crop-damage-global-warming?tgt=nr