Nalassus laevioctostriatus
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Nalassus laevioctostriatus on oak |
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| Scientific name | ||||||||||||
| Nalassus laevioctostriatus | ||||||||||||
| ( Goeze , 1777) |
Nalassus laevioctostriatus is a beetle from the family of darkling beetles and the subfamily Tenebrioninae . The genus Nalassus is represented in Europe by around 50 species , the range of which is usually very limited. Previously, the species wasassigned tothe genus Cylindronotus .
Characteristics of the beetle
The beetle has a body that is arched lengthways and widthways with an oval outline, the rear end of which is not drawn out into a point. The body is inconspicuously brownish to black-brown in color and appears bald and shiny. It reaches a length of seven to eleven millimeters. Legs, antennae and usually the underside are red-brown.
The head falls forward. The cheeks are expanded so that the base of the antennae is covered when viewed from above. The eleven-limbed antennae are thread-shaped, about the same thickness everywhere, and red-brown; they reach the rear edge of the pronotum.
The pronotum is edged laterally and at the base, the lateral edge is smooth, but not the edge of the base. On the side, the pronotum is rounded outwards everywhere and broadest behind the middle. It is shinier than in the species Nalassus dermestoides because the microstructure is finer.
The wing covers have roughly right-angled shoulders and have clear stripes of dots . The part of the name "octostriatus" refers to the fact that there are eight point stripes on each wing cover (octo (lat.) = Eight, striatus (lat) = striped). Directly above the wing edge, however, a ninth dot stripe is at least indicated. The spaces between the strips are only slightly curved. The wing cover seam is edged, especially towards the tip. The puncture of the elytra is stronger than that of the pronotum, the individual points can be connected by horizontal wrinkles.
The tarsi are long, the first link is longer than the two following links together, the claw link is shorter than the sum of the first three tarsi. Fore and middle tarsi are five-limbed, the hind tarsi four-limbed (tarsi formula 5-5-4). The fore legs are imperforated, the front rails are not noticeably widened towards the end and have no serrated outer edge. Not only the front tarsi but also the middle tarsi of the male are clearly expanded.
biology
The beetle can be found under the loose bark of old oaks, but also other trees. The larvae dig in the damp forest floor in the presence of decaying wood. In addition to organic substances (wood residues, parenchymal tissue residues, pollen , algae , bacteria ), mineral soil particles are also found in the intestinal contents . In the intestinal excretions one always finds wood residues. The adult beetles eat green algae of the genus Pleurococcus , which they find on tree bark or perhaps indirectly in lichens.
distribution
The species is common in western and central Europe and becomes rare towards the east. Countries with occurrences are specified: France , Belgium , Luxembourg , Ireland , Germany , the Czech Republic , Slovakia and Poland .
literature
- Heinz joy , Karl Wilhelm Harde , Gustav Adolf Lohse (ed.): The beetles of Central Europe . tape 8 . Teredilia Heteromera Lamellicornia . Elsevier, Spektrum, Akademischer Verlag, Munich 1969, ISBN 3-8274-0682-X .
- Gustav Adolf Lohse, Wilhelm H. Lucht: The beetles of Central Europe . tape 13 , 2nd supplement volume with catalog section. Goecke & Evers, Krefeld 1992, ISBN 3-87263-043-1 .
Individual evidence
- ↑ a b Nalassus laevioctostriatus in Fauna Europaea. Retrieved January 5, 2011
- ^ Nalassus at Fauna Europaea. Retrieved December 5, 2011
- ↑ J. Green: The Food of Cylindronotus laevioctostriatus (Goeze) (Col., Tenebrionidae) and its larva Entomologist's Monthly Magazine (1951), 87: 19.
