Identification
Scientific Name:
Dytiscus sp.
Common Names:
dytiscids, water beetles, predaceous diving beetles, water bugs

Classification
Class: Insecta
Order: Coleoptera
Family: Dytiscidae
Genus: Dytiscus
Species: There are over 3 200 species of water beetle.

 

Habitat
Water beetles are found in most parts of the world. Since they are aquatic insects, they occur naturally near ponds, lake and streams. In the spring, we may even come across them in the murky green water of our swimming pools.

Profile
" Submarine " is probably the best word to describe the water beetle The bodies of these aquatic beetles are perfectly hydrodynamic. The females' backs are so smooth that males wanting to mate have to use adhesive suckers to stay on them. To dive or to resurface, water beetles compress or dilate their air reserves, based on the ballast-tank principle. They use the " frog kick " for swimming, using their long hind legs like oars.
 
To breathe under water, frogmen carry oxygen tanks on their backs. Water beetles wear theirs under their backs! They surface to take in air through the tip of their abdomen. At the same time, they slightly open the two rigid casings that cover their abdomen (the elytra) and trap an air bubble under them. These robust insects are very resistant and can live for two to five years.
 
Water beetles are the sharks of the insect world. They are formidable aquatic predators in both the larval and adult stages. They have been known to attack prey much larger than themselves, such as fish and crustacea. The water beetle larva is particularly rapacious and deserving of its nickname of " water tiger ".

While swimmers extraordinaire, water beetles are also perfectly capable of flying. Like moths, they are drawn to light.
  

During the winter, some dytiscids burrow into the mud and become dormant. Other species remain active, retrieving air bubbles trapped under the ice.
  

If a fish swallows a water beetle, it will immediately spit it out. This is because the water beetle has a unique defense system; it releases steroids that produce nausea. If only Jonah had known!