Have you seen Dytiscus marginalis swimming?

Have you ever found unwelcomed pests in your garden pool? Sure you did. A huge amount of mosquito larvae and other insects are most common, but here and there you may see a frog or other animals. We saw and recorded a little bug known as the “little diver” in our pool. This happened now after the winter, when the pool was winterized. This year we decided to change the foil, so we did not cover the pool and this little creature found our pool interesting.

Watching little diver

Little divers obviously like our pool and began to multiply. We found a big one and a small one. We also found lot of mosquito larvae there, so they have plenty to eat. Watching the little creature swim and dive is quite entertaining. You can check our short video below but before you watch it, you should learn some facts about this little predator.

Photo: Radek Štěpán

Predatory aquatic insects

Dytiscus marginalis, also known as the great diving beetle, lives in fresh water. You do not want larvae of this predator in your fish tank for example. You may find the great diving beetle in other water bodies as well, especially, if there are mosquitoes. It loves mosquito larvae, but it also eats fry, small fish or small amphibians. The great diving beetle mates in the spring, when a female lays up to 1 000 eggs.

Photo: Radek Štěpán

Great flying insect

These creatures can fly too! but before they do they release a special liquid that makes them heavier and keeps them underwater. When they return back to the water, they suck it up again and can go diving. And how can you tell females from males? Males have smooth elytra and females have serrated elytra. Another interesting fact is that they have to hold the breath so, they emerge to breathe about seven times in an hour.

Preview photo: Radek Štěpán