Although N. glauca live in the water, they breathe atmosphere air and do not have gills.
When these insects are diving or resting under the water surface, they create a film of air that surrounds their body.
This air film is also known as a superhydrophobic coating or surface, and it prevents the insect from becoming wet.
It also reduces the drag (physics) that is created when diving.
To be able to create this air film around it, N. glauca is covered in hairy structures, except on its head and legs.
There are two types of hairs and air retention is maximized by having both types: setae and microtrichia.
The most important part in creating an air film is the density of the hairs.
Notonecta glauca has dense microtrichia and their air film can last up to 120 days.
The air film cannot last forever because as an insect respires (breathes), the oxygen partial pressure will decrease and nitrogen partial pressure will increase, causing the air bubble to decrease in size.
Although N. glauca live in the water, they breathe atmosphere air and do not have gills. When these insects are diving or resting under the water surface, they create a film of air that surrounds their body. This air film is also known as a superhydrophobic coating or surface, and it prevents the insect from becoming wet. It also reduces the drag (physics) that is created when diving. To be able to create this air film around it, N. glauca is covered in hairy structures, except on its head and legs. There are two types of hairs and air retention is maximized by having both types: setae and microtrichia. The most important part in creating an air film is the density of the hairs. Notonecta glauca has dense microtrichia and their air film can last up to 120 days. The air film cannot last forever because as an insect respires (breathes), the oxygen partial pressure will decrease and nitrogen partial pressure will increase, causing the air bubble to decrease in size.
Notonecta glauca