Agabus undulatus 08 july 2012
Agabus undulatus

This Agabus species is easily recognisable by the wavy lines on it's back, as the suffix undulatus points out. The 7.5 mm long specimen on the picture above was caught in a little canalised stream. According to Foster & Friday (2011), Agabus undulatus is an inhabitant of permanent, well vegetated stagnant water in fenland, and there is a single record for a stream. Van Nieukerken (1992) mentions that the beetle is also found in canalised streams. The forementioned stream is never completely dry.

The pictures below show that the wavy line is attached to a bright sideline that finishes on the rear half of the wing cases (elytra). This feature causes the illusion that there are two separate light spots on that spot when viewed from above, and from that viewing position we may also see two pale dots on the rear, which are in effect two small vertical stripes as can be seen from aside. A closer look at the spot and lines reveals these are places where the darker colouring is not present, so it's the pale chitin we see there. Click on the "page 3 picture below to see that more clearly.

Agabus undulatus - sideview 08 july 2012
This side-view shows the yellow border
that is connected to the wave shaped lines.
Agabus undulatus - rear view 08-07-2012
vergroting The beetle appears to have several
separate bright spots on its back.

There aren't any pictures of this beetle's larvae on this site, Vainstein (1969) made drawings of the larvae. They have the general appearance of a medium sized Dytiscus larvae.

Click on one of the pictures below to see more of Agabus undulatus.

Agabus undulatus 08-07-2012
page 2
Agabus undulatus 08-07-2012
page 3: no colour on the spots
Agabus undulatus 08-07-2012
page 4: underside


Vainstein, B.V. (1969). "Larva of Agabus undulatus (Koch, 1837)". Original title: "Lichinka Agabus undulatus (Koch, 1837)". Biologiya Vnutrennikh yod, Informatsionne Byulleten, Akademiya Nauk SSSR, No. 3, p. 21-22, 1969. Retrieved july 2013 from

More sources on the Waterbeetles bibliography.

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All pictures on this site were made by Gerard Visser (Aadorp, Netherlands), unless stated otherwise. All rights remain with him. These pictures may not be used for purposes any other than private viewing or printing. Do NOT hardlink to these pictures or place them on other websites without the author's approval. Should you need them for purposes which include third parties, you must ask the author permission by e-mail. People, who want to use this pictures for exhibitions or publications or educative material are much encouraged to do so, after approval as mentioned and giving the normal credits.

© G.H. Visser 25-07-2013
rev. 14-04-2022

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