Study shows how insects breathe underwater

CAMBRIDGE, Ill., July 31 (UPI) -- Hundreds of insect species spend much of their time underwater looking for food and U.S. scientists have determined how such insects continue to breathe.

Massachusetts Institute of Technology mathematicians say such insects, by virtue of their rough, water-repellent coat, trap a thin layer of air on their bodies. Those bubbles not only serve as a finite oxygen store, but also allow the insects to absorb oxygen from the surrounding water.

"Some insects have adapted to life underwater by using this bubble as an external lung," said MIT Associate Professor John Bush, a co-author of the study.

He said the air bubbles allow insects to remain below the surface indefinitely and dive as deep as about 100 feet, said the study co-authored by Bush and Morris Flynn, a former MIT applied mathematics instructor. Some species, such as Neoplea striola, which are native to New England, hibernate underwater all winter.

The MIT researchers said they are the first to calculate the maximum dive depths and describe how the bubbles remain intact as insects go deeper underwater, where pressure threatens to burst them.

The research is reported in the Aug. 10 issue of the Journal of Fluid Mechanics.