Common Wasserflorfliege ( sialis lutaria )

The mud flies or Wasserflorfliegen ( Sialidae ) are a family of Big Wings ( Megaloptera ). They are widespread with about 60 species worldwide. The Holarctic is their main area of ​​distribution. Their larvae often come in large numbers before and therefore provide an important food for fish dar.


The animals have a relatively small and plump physique with forewing length 10-20 mm, while the females are usually larger than males. They are usually brown in color and do not have simple eyes ( ocelli ). Your pronotum is relatively broad and less long than it is wide. Her legs are strongly built and have five Tarsenglieder. The fourth element is widened lobed. Like the other Big Wings they have a very projecting Flügeladerung on their large wings that are placed in the position of rest roof-like over the body.

The larvae on the abdomen of seven pairs of characteristic feathery gills and a long, tapered rear body end. They have large mandibles.

Way of life

The adults are diurnal and fly sluggishly. They are found in Central Europe from May to June on the riverbank vegetation, but they live only briefly.

The females lay up to 2000 eggs in groups of about 200 pieces from the riparian vegetation of various types of waters. The resulting hatching larvae can fall into the water. Initially live in water, buried in the mud later. They occur in up to 18 meters depth. They feed on prey on insect larvae, worms and small clams. You need to usually two years to develop, overwinter as larvae and both times by live 10 larval stages. They pupate on the shore under the earth. The doll digs before hatching of the imago to the surface.

Systematics ( Europe)

The mud flies come in Europe with only 10 species of the genus sialis.

From Baltic amber ( Eocene ) ( Protosialis ) baltica are also the fossil species sialis sialis groehni and described. This is the so far oldest fossil record of this family.