Scarlet flat beetle

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Scarlet flat beetle
Scarlet beetle on a poplar

Scarlet beetle on a poplar

Systematics
Class : Insects (Insecta)
Order : Beetle (Coleoptera)
Subordination : Polyphaga
Family : Flat beetle (Cucujidae)
Genre : Cucujus
Type : Scarlet flat beetle
Scientific name
Cucujus cinnaberinus
( Scopoli , 1763)

The scarlet flat beetle or scarlet beetle ( Cucujus cinnaberinus ) is a beetle from the flat beetle family . The genus Cucujus is represented in Central Europe with only two species that are very similar to each other.

The genus Cucujus is named after the Brazilian Cúcujo, which means "shining beetle". The species name cinnaberīnus is a wrong spelling for cinnabarīnus, a, um ( Latin ) and means "vermilion". The name refers to the beetle's intense red color.

The hidden beetle is quite rare and is listed in Appendices II and IV to Natura 2000 .

Characteristics of the beetle

Because of its striking color, the species can be confused with the scarlet fire beetle when viewed superficially , but with a length of eleven to fifteen millimeters it is smaller than the scarlet fire beetle and much more flattened (Fig. 3).

The head and pronotum are colored red and slightly shiny, the wing covers are also red, but matt. The red color disappears quickly with dead material (Fig. 2 to 3). The tarsi are brown, the rest of the legs , antennae and underside black.

The flattened, triangular head points forward. It is strongly punctured (Fig. 6). The upper jaws are clearly visible from above. They are black and end in three asymmetrical teeth that interlock when the upper jaw closes (Fig. 3). The upper jaws of the very similar Cucujus haematodes are red. The four-part jaw probe and the three-part lip probe have a trimmed end link (Fig. 7). The eyes sit to the side and are oriented slightly forward. Behind the eyes, the temples are strongly widened like a cheek (Fig. 3 and 6). The eleven-link antennae are thread-shaped and deflected in front of the eyes. They are about half the length of the body. The first link is stronger but not distinctly shaft-shaped.

The pronotum is narrower than the temples and the elytra. It is dotted like the head. Its back and front corners are clearly developed, from the front to the back corners it narrows almost uniformly. Its side edge is irregularly serrated and, in contrast to Cucujus haematodes, blackened.

The wing covers are strongly flattened and dull. They only have a fine row of dots next to the raised seam , otherwise they are without rows of dots. The shoulders are well developed. The side edges of the wing covers are bent downwards at right angles to the disk and run parallel to each other. The disc is pressed down slightly towards the seam. The elytra are rounded apically in a semicircle. A clear keel runs around the shoulders and on the side of the wing covers (Fig. 2, green in the copy below). The triangular label is clearly visible, shiny and dotted.

The front and rear hips are small, spherical and clearly separated from each other (Fig. 5). The rear hips are also separated from each other. The first tarsal segment is quite small and hidden in the end of the splint , so if you look at it superficially you count one tarsal segment less (Fig. 4). In the female all tarsi are five-limbed, in the male only the front and middle tarsi consist of five limbs, the hind tarsi are four-limbed (Fig. 8). The legs are usually oriented to the side.

Characteristics of the larva

The amber-colored larva is similar to that of the fire beetle that is common in the same biotope . It is flat, the exoskeleton is well chitinized and hardened. The last segment of the body has two pairs of straight appendages (picture). The segments are, however, all wider than long, in contrast to the larva of the fire beetle. In the last larval stage, the larvae reach a length of up to 26 millimeters.

Cucujus cinnaberinus couple.JPG
Cucujus cinnaberinus detail.jpg
Green copy keel
Fig. 1: Mating Fig. 2: Shoulder, wing cover
Cucujus cinnaberinus front.jpg Cucujus cinnaberinus tarsus.jpg
Fig. 3: Front view Fig. 4: Five limbs of the tarsus,
colored copy below
Cucujus cinnaberinus under.jpg Cucujus cinnaberinus part.jpg
Fig. 5: Bottom
Cucujus cinnaberinus Reitter1.png
A: Upper lip B: Upper jaw
C: Lower jaw with jaw buttons
D: Lower lip with lip buttons 		Fig. 6: Front part
Cucujus cinnaberinus Reitter2.png
A: female B: male
Fig. 7: Mouth parts
according to ( Reitter ) 		Fig. 8: Hind tarsus
according to (Reitter)

biology

The beetle can be found under the bark of dying or dead deciduous trees, only in exceptional cases under conifer bark (rotten wood dwellers). The larvae also develop there. It takes two years or more to develop. The larvae pupate in summer. The doll's cradle is similar to that of the shotgun and is surrounded by wood chips. The adults hatch about ten days after pupation at the end of summer or in early autumn, but remain in the pupal chamber for a few more days. They hibernate under the bark and reproduce in spring.

Adults are most common in early spring. A second maximum of occurrence is in autumn. They only get outside or under the bark again through cracks in the bark; they cannot gnaw a hole like most wood-dwelling beetles. In April and May the beetles swarm towards evening. Copulation takes place under the bark at the beginning of the growing season. During copulation, one can observe how the males nibble on the females' antennae (Fig. 1).

The females lay their eggs under the bark of suitable trees, whereby the degree of decomposition of the bast layer is important. The host plants are mainly poplar ( Populus ), maple ( Acer ), beech ( Fagus ), horse chestnut ( Aesculus hippocastanum ) and oak ( Quercus ). The larvae are found in moist bast which has become brown due to decomposition. In the laboratory experiment, six larval stages were counted in the year of pupation; the total number of molts is not known. The larvae ate plenty of already severely decomposed bast and the small organisms adhering to it, but development is clearly hindered without additional animal food.

The adult animals were predatory in the experiment. The prey animals were held with the mandibles , squeezed and the soft tissues that emerged were eaten.

Beetles kept at least in captivity are nocturnal and very shy during the day. After being uncovered, they often freeze in a posture with their heads bent and legs drawn up, after which they quickly crawl into cracks (Fig. 6). The larvae live gregariously and react to contact by bending over in rapid alternation to the left and right.

distribution

The distribution area extends from France through Switzerland and Austria to Eastern Europe ( Poland , Ukraine , Czech Republic , Slovakia , Hungary , Romania and Serbia with Montenegro ). In Germany , the beetle is only known from southeast Bavaria and recently also from Baden-Württemberg and Hesse . The species is also reported from Norway , Sweden and Finland .

The reports are, however, declining in the peripheral areas of the distribution area. There are only historical reports from Spain and in Italy , too , the species was considered extinct for a long time. On the other hand, the beetle also seems to be reestablishing itself in certain areas, for example in newly created poplar avenues.

The sites are mainly along the floodplains of larger rivers. The beetle is also found more frequently in mountain regions near naturally managed forests. It is discussed whether there are two ecological races or whether it is a question of the fragmentation of a formerly contiguous area of ​​distribution.

Hazard and protection

The scarlet beetle is listed in Annexes II and IV of the Fauna-Flora-Habitat Directive ( Directive 92/43 / EEC ). He thus enjoys international protection. In the Red List of Threatened Species of IUCN is it "at risk" and classified as listed in the Red Lists of many countries. In the Red List of Threatened Species in Germany, the species is under category 1 (threatened with extinction).

The species prefers locations with relatively high humidity. The number of finds is declining in terms of distribution. This is due on the one hand to the declining supply of suitable breeding trees, and possibly also to the shading of dead wood in the commercial forest. Riparian forest locations and mixed deciduous mountain forests should be preserved and developed and old and dead wood structures should not be destroyed during thinning. The exchange of isolated populations should be made possible.

literature

  • Heinz joy, Karl Wilhelm Harde, Gustav Adolf Lohse (ed.): The beetles of Central Europe . tape 7 . Clavicornia. Spektrum Akademischer Verlag, Munich 1967, ISBN 3-8274-0681-1 .
  • Svatopluk Bily: Coléoptères, adaptation française. Verlag Gründ, 1990, ISBN 2-7000-1824-9 . (French)
  • Edm. Reitter: Fauna Germanica, the beetles of the German Empire. Volume III. KG Lutz 'Verlag, Stuttgart 1911.
  • Ulrich Straka: On the biology of the scarlet beetle Cucujus cinnaberinus (SCOPOLI, 1763). In: Contributions to entomofaunistics. 8 (2007), pp. 11-26. (as PDF; 419 kB)

Individual evidence

  1. ↑ a b Cucujus cinnaberinus in Fauna Europaea. Retrieved December 5, 2011
  2. ↑ Cucujus at Fauna Europaea. Retrieved December 5, 2011
  3. ↑ Sigmund Schenkling: Explanation of the scientific beetle names.
  4. ↑ Appendix II of Natura 2000
  5. ↑ Appendix IV of Natura 2000
  6. ↑ Bild Larve ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.entomologie-stuttgart.de
  7. ↑ a b c d J. Horak, K. Chobot: Phenology and notes on the behavior of Cucujus cinnaberinus : points for understanding the conservation of the saproxylic beetle. In: North-Western Journal of Zoology. 7 (2) 2011, pp. 352-355. Article No .: 111215 as PDF
  8. ↑ a b c Ulrich Straka: On the biology of the scarlet beetle Cucujus cinnaberinus (SCOPOLI, 1763). In: Contributions to entomofaunistics. 8 (2007), pp. 11–26 (as PDF; 419 kB)
  9. ^ ARGE SWD coleopterologists
  10. ^ Scarlet beetle occurrence found near Ginsheim-Gustavsburg. Retrieved September 1, 2014 .
  11. ↑ Distribution maps with historical and new finds
  12. ↑ J. Horak, E. Vavrova, K. Chobot: Habitat preferences influencing populations, distribution and conservation of the endangered saproxylic beetle Cucujus cinnaberinus (Coleoptera: Cucujidae) at the landscape level. In: Eur. J. Entomol. 107 (1) 2010, ISSN  1210-5759 , pp. 81-88. (as PDF)
  13. ↑ Jiří Schlaghamerský, V. Manak, P. Cechovsky: On the mass occurrence of two rare saproxylic beetles, Cucujus cinnaberinus (Cucujidae) and Dircea australis (Melandryidae), in South Moravian floodplain forests. In: Revue d'Écologie (La Terre et la Vie). Société nat. de protection de la nature, Paris 10/2008, ISSN  0249-7395 , pp. 115-121.
  14. ↑ A. Mazzeia, T. Bonaccia, E. Contarinib, T. Zettoa, P. Brandmayra: Rediscovering the 'umbrella species' candidate Cucujus cinnaberinus (Scopoli, 1763) in Southern Italy (Coleoptera Cucujidae), and notes on bionomy. In: Italian Journal of Zoology. Volume 78, Issue 2 (2011), pp. 264–270, doi: 10.1080 / 11250003.2010.485210
  15. ↑ Jakub Horak, Karel Chobot, Alexander Kohutka, Roman Gebauer: Possible factors influencing the distribution of a threatened saproxylic beetle Cucujus cinnaberinus . In: The Coleopterists Bulletin. 62 (3) 2008, pp. 437-440. doi: 10.1649 / 1119.1
  16. ↑ Red lists at BioNetworkX
  17. ^ Cucujus cinnaberinus (Scopoli, 1763). Insects (FFH species - Appendix II). Retrieved March 14, 2017.

Web links

Commons : Scarlet Beetle  - Album with pictures, videos and audio files