Ennearthron cornutum

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Horned sponge beetle
Ennearthron cornutum, female

Ennearthron cornutum , female

Systematics
Class : Insects (Insecta)
Order : Beetle (Coleoptera)
Family : Sponge beetle (Ciidae)
Genre : Ennearthron
Type : Horned sponge beetle
Scientific name
Ennearthron cornutum
( Gyllenhaal , 1827)

Ennearthron cornutum is a beetle fromthe sponge beetle family . The genus Ennearthron is represented in Europe with 6 species. The German name Horned Sponge Beetle is usedoccasionally.

Notes on names and synonyms

The beetle was first described by Gyllenhaal in 1827 under the name Cis cornutus . The Latin short description contains the sub-sentence thorace capiteque maris antice bicornutus ( Latin for breast and head of the male with two horns in front ). This explains the species name cornutum from Latin horned .

The generic name Ennearthron is from Altgr. εννέα "ennéa" for "nine" and άρθρον "árthron" for "limb". The name refers to the antennae, because the genus Ennearthron was separated from the genus Cis by Mellié in 1847 because of the nine-segment antennae , in which the beetles with ten-segment antennae remained.

After the renaming of Cis cornutus in Ennearthron cornutum , the name Cis cornutus was reassigned by Blatchley in 1910 for a North American beetle.

Occasionally, Ptinus concinnus is given as a synonym for Ennearthron cornutum . The description of Ptinus concinnus by Marsham 1802 alone is too scanty to be able to understand that it is the same species of beetle.

Pictures of the male
Ennearthron cornutum up.jpgEnnearthron cornutum under.jpgEnnearthron cornutum front.jpg
Fig. 1: Males from above, below and in front
Ennearthron cornutum detail male.jpg Ennearthron cornutum antenna Fowler.png
Fig. 2: Side view of the front part, copy
colored on the left , green pronotum, blue head shield 		Fig. 3: Feeler,
after Fowler

Characteristics of the beetle

The beetle reaches a length of one and a half to almost two millimeters and is about 0.4 times as wide as it is long. The strongly arched body is cylindrical brownish to reddish brown and slightly shiny. The underside is darker, legs, buttons and feelers are yellow, the tip of the feeler is darker. The short hairs are gray to yellowish, scale-like and protruding.

The head is wider than it is long. It is strong but not densely punctured . It has a dimple on its forehead and is indented across the front. Before that, the head shield in the female is slightly bent up and cut almost straight, in the male the bent up head shield is cut out in the middle, next to it drawn out on both sides to a darker colored tooth (Fig. 2 left blue). The black eyes are clearly domed. The nine-segment antennae (Fig. 3) are deflected on the inner edge of the eyes. The three large, separate end links of the antennae form a loose club. The end link is noticeably longer than the two penultimate links. The base part of the antennae is large with a stalked end button, the second part is much smaller, short and egg-shaped. The third link is thin and as long as the three following combined. These are about the same size and wider than they are long. The upper jaw is thick, three-sided with a serrated tip. The lower jaw is bilobed. The jaws are four-part. The three-part lip switch end with a cylindrical link.

The pronotum narrows towards the front. It is about the same length as it is wide, in the male it is a bit wider. The sides and base of the pronotum are finely edged, the front angles are blunt, the back angles are rounded. The side edge is mostly visible from above in the female, but only near the rear corners of the male because of the larger pronotum. The pronotum towers over the head in front. In the female it is simply rounded there, in the male it is deeply cut out and pulled out into a croissant on each side (Fig. 2 left green). The horns of the pronotum run roughly parallel to the teeth of the head shield, but the cutout on the pronotum is deeper than the cutout on the head shield, the horns on the pronotum are more pointed and the teeth on the head shield are wider and less spaced than the horns on the pronotum. The dots are moderately strong and very dense, the gaps are smooth, in the female smaller than the dots themselves. The scaled hairs protrude in different directions, mostly they are directed backwards.

The label is small, rounded to triangular.

The elytra are more than twice as long as the pronotum and almost three-quarters times as long as together wide. They widen slightly towards the rear in the female, but hardly in the male. The puncture is a little denser than on the pronotum. The spaces between the points are slightly wrinkled and in both sexes smaller than the points themselves. The scaled hairs are indistinctly lined up. The wing covers are rounded to a point at the end.

The legs are yellow. The tarsi are four-part, the first part is hidden in the cutout of the splint, the end part is longer than the previous ones together. The outermost tip angle of the front splint is drawn out into a tooth in the male, but this is weaker and often barely developed in the female (taxobild).

larva

Fig. 5: Perris larva, partially colored. Fig. 290: Top view, Fig. 292: Mouth parts from below, tongue blue, lip probe green, lobe of the lower jaw light red, jaw probe dark red; 293: Upper jaw seen from the side; 294: sensor; 295: O cells of a page; 296: anal segment from above; Fig. 297: Anal segment from the side, anal wart red (much clearer in Saalas); Fig. 298: Leg, hip red, thigh blue, splint green

The elongated larva (Fig. 5, Fig. 290) becomes about three millimeters long in the last stage. It consists of the head, the three-part chest section and nine abdominal segments. The dimensions of the chest segments do not differ significantly from those of the abdomen. Except for the slightly flattened underside of the breast segments, head and anal segment, the larva is cylindrical. Except for the head and end of the body, it is white or very pale reddish and of a fleshy consistency.

The rounded head is smooth, it has a short longitudinal furrow on the vertex and a transverse dimple is indicated on the forehead. The head has fine hair of different lengths. It is reddish, darker at the front edge. The reddish upper lip has the shape of a half disk and is very finely haired. The strong and hardened upper jaws (Fig. 5, Fig. 293) are black in the front third and hardly touch each other. Viewed from below, they appear beveled and seen from the side, a tooth can be seen opposite the bevel. The lobe of the lower jaw (Fig. 5, Fig. 292 light red) is elongated, rounded at the tip and bordered with bristle-like cilia, which form a kind of rake. The maxillary palps (Fig. 5, Fig. 292 dark red) hardly protrude beyond the lobe. They are slightly curved inward and tripartite, the limbs about the same length and tapering towards the front. The lower lip (Fig. 5, Fig. 292 blue) is narrowed and elongated between the two short, two-part lip buttons (Fig. 5, Fig. 292 green). The sensors are shown in Fig. 5, Fig. 294. The penultimate link is cut off diagonally at the top and is surmounted on the inside by a small outgrowth that ends in a long hair. The last link is very slender and turned slightly outwards. On each side of the head there are three black ocells, not quite in a row, of which two are brought closer together (fig. 5, fig. 295).

The chest section is slightly wider than the head and has some stiff hair on the sides and top. The first link is longer and slightly narrower than the following two, it is slightly rounded at the front. Each of the three segments of the chest section has a pair of short, laterally protruding legs (Fig. 5, Fig. 298). The strong hips (Fig. 298 red) are conical. Legs (Fig. 298 blue) and splints (Fig. 298 green) are hairy long and about the same length. The reddish claws are slightly curved.

The abdomen is hairy above, below, and scattered to the sides. The first two segments are slightly smaller than the following. The seventh segment of the abdomen is very slightly reddish on top, the eighth is reddish except for the front and rear edges, the last segment (anal segment) is red, more densely hairy and more chitinized. This segment (Fig. 5, Fig. 296 from above and Fig. 297 from the side) ends in two parallel, approximate, short, slightly curved, pointed and hard body appendages. On the underside of this segment there is a retractable anal wart (colored reddish in Fig. 296). The top of the anal segment is flattened and has a spoon-like depression. In this four triangular, pointed teeth arise, which are far apart; the front ones are significantly smaller than the rear ones.

The first pair of spiracles is located at the front edge of the middle chest section, the others are in the first third of the first eight abdominal segments.

Doll

The pupa already clearly resembles the imago , the extensions of the pronotum can already be seen in the male. The pupa is soft-skinned and only sparsely hairy. On the side of the front chest you can find some very fine white hairs, on the back of the front, middle and rear chest you can see two rows of six or eight such hairs each. There are eight longitudinal rows of such hairs on the back of the abdomen. The abdomen ends in two slightly bent back warts with slightly horny tips. They make it possible for the doll to be supported and thus for curvatures of the abdomen to change its position.

biology

The beetle feeds on fungi as a larva and as an imago. The beetle is found on dry and fungal branches of trees that are infected by tree sponges with hard fruiting bodies, but mainly on and in the fruiting bodies of these fungi, in which the larvae also develop. Depending on the occurrence of these fungi, the beetles are found in deciduous and mixed forests, less often in coniferous forests, but also in parks on hedges and single trees. In Central Europe, species of the genus Phellinus (fire sponges) as well as Shaggy Schillerporling , Burnt Smoke Porling , Oak Tangled , Birkenporling , Red-edged Tree Sponge and Tinder Sponge are often mentioned as host fungi . The presence of the beetle on twenty species of sponges is reported from the Moscow area . Reibnitz gives the number of hosts as thirty. In Ennearthron cornutum, the range of colonized host fungi is not determined by the degree of relationship of the host fungi, as is the case with many oligophagous mycetophages, but rather by the hardness of the host's fruiting body. Ennearthron cornutum colonizes species with hard fruiting bodies. The pronounced polyphagy of the beetle is an exception within the sponge beetle. According to the host trees of the host fungi, the beetles are reported by various deciduous and coniferous trees ( beeches , oaks , ash trees , willows , birches , more rarely firs and pines ). In southwest Germany the beetle accounts for almost a tenth of all finds of the forty or so sponge beetle species found there. The beetle can be found there from the plain to the high altitudes of the Black Forest . In Finland it has been shown that the beetle becomes rarer as its habitat becomes smaller and more isolated.

Experiments with scent traps in Finland show that among the beetle hosts there are both species whose scents clearly attract the beetle (red-rimmed tree sponge), but also other host species (tinder sponge) whose scents do not have a statistically proven attraction on the beetle. A study in Northern Europe showed that the beetles do not choose fruiting bodies near the ground for reproduction. Presumably this is due to the increased moisture close to the ground. So - at least in the north of the distribution area - warmer locations with dry soil and in a south-westerly position are preferred for oviposition.

The eggs are only laid on the hosts when they have already aged. This indirectly confirms the rule that monophagous insects that develop in tree sponges colonize the host plant at an early stage of development of the fruiting bodies. Often, Ennearthron cornutum is still the only species to be found in old fruiting bodies . Beetle larvae are only found in fungi in an advanced stage of decomposition, in which vegetative reproduction by spores has already been completed and the fruiting body has largely died, but the external and internal structures are still clearly visible. It is assumed that after the spores have matured, the possibly toxic defense substances of the host fungi lose their effectiveness and the beetle does not need to develop any resistance to them. However, the possibility is also discussed that polyphagous mycetophages relatively easily develop a multi-resistance to the chemical defense substances of the fungi, which enables them to develop in a broad spectrum of host fungi. The preferred location of the larvae in the fruiting body varies according to the host fungus (only in the Trama or between the hymenophore and the Trama) and the choice of the fungus part seems to depend on its hardness.

Investigations in the Kampinos National Park in Poland caught the beetle all year round. 43% of all catches were in April and May, a second, much flatter maximum was between September and November with around 33% of the catches. The only catches below 1% were in December. For southwest Germany it has been proven that from spring to autumn not only beetles but also newly hatched beetles are found. Both larvae of various stages and beetles overwinter. The development cycle of Ennearthron cornutum is therefore not strictly linked to the course of the year. It is generally known about the development that it usually takes longer in polyphagous mycetophages than in oligo- or monophageous.

distribution

The beetle occurrence is limited to Eurasia . The distribution area is mainly in Europe, where the species is distributed everywhere except in peripheral areas. The beetle is absent in southern Europe in Portugal and on all islands except Corsica , and it is also absent in large parts of south-eastern Europe ( Greece , European Turkey , Slovenia , Macedonia , Serbia , Montenegro , Albania , Moldova and Bulgaria ). In the east, the species is reported from the Caucasus, the Middle East and Belarus , but it is absent in southern, northwestern and eastern European Russia. In the north, the occurrence in the Baltic states is unclear, according to one source the beetle occurs at most in Estonia , where the occurrence is questionable, according to another source it occurs in both Estonia and Latvia . Furthermore, the species is missing in the Kaliningrad region , on Iceland and the more northern archipelagos, and there are no reports of finds from the small states of Andorra , Gibraltar , Vatican City , San Marino and Monaco .

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 , p. 294 .
  • Klaus Koch : The Beetles of Central Europe . Ed .: Heinz Freude . tape 3 : ecology . Goecke & Evers, Krefeld 1992, ISBN 3-87263-042-3 , pp. 261 .
  • Edmund Reitter : Fauna Germanica, the beetles of the German Empire V. Volume, KGLutz 'Verlag, Stuttgart 1916, p. 104.
  • Gustav Jäger (Ed.): CG Calwer's Käferbuch. K. Thienemanns, Stuttgart 1876, 3rd edition, p. 399.

Web links

Commons : Ennearthron cornutum  - album with pictures, videos and audio files

Individual evidence

  1. ↑ a b c Fauna Europaea systematics and distribution of Ennearthron cornutum , accessed on October 19, 2017.
  2. ↑ Theodor CH Cole: Dictionary of invertebrates = Dictionary of invertebrates . Springer Spectrum, Berlin / Heidelberg 2017, ISBN 978-3-662-52868-6 , p. 370 (Latin, German, English, limited preview in Google Book Search).
  3. ^ Leonhard Gyllenhaal: Insecta Svecica - Classis I Coleoptera. Volume I, Part IV: Lipsiae. Leipzig 1827 Description Cis cornutus in the Google book search.
  4. ↑ Sigmund Schenkling: Explanation of the scientific beetle names (species)
  5. ↑ Sigmund Schenkling: Explanation of the scientific beetle names (genus).
  6. ^ Under Mélanges et Nouvelles ( Miscellaneous and News ) by Guérin-Méneville presented draft of Mellié for the monograph of the genus Cis in Revue Zoologique par la Société Cuvierienne. Volume 10, Paris 1847 p. 110 Ennearthron
  7. ↑ WS Blatchley: An illustrated descriptive catalog of the Coleoptera or beetles (exclusive of the Rhynchophora) known to occur in Indiana with bibliography and descriptions of new species. Indianapolis 1912 p. 898 Cis cornutus n. Sp.
  8. ↑ synonym in BioLib (Czech).
  9. ↑ a b Olivier Rose: Les Ciidae de la faune de France continentale et de Corse mise à jour de la clé des genres et du catalog des espèces (Coleoptera, Tenebrionoidea). In: Bulletin de la Société Entomologique de France. 117, No. 3, 2012, pp. 339-362, here p. 352 ( researchgate.net PDF).
  10. ↑ Thomas Marsham: Entomologia britannica sistens insecta Bretanniae indigena…. Volume 1: Coleoptera. P. 87, No. 19
  11. ^ A b Canon Fowler: The Coleoptera of the British Islands. Volume 4, London 1890 Description of Ennearthron cornutum , plate 119, Fig. 11a antennae of Ennearthron cornutum.
  12. ↑ Ciidae determination table in the Coleonet.
  13. ↑ a b c d Édouard Perris: Histoire des Insectes du Pin maritime (Suite 1) In: Annales de la Société Éntomologique de France 3rd series, 12th volume, Paris 1854 Description of the larva of Ennarthron cornutum p. 639 , fig Larva plate 18 in the annals (plate 6 after Perris) Fig. No. 290-298, lettering of the figures
  14. ↑ HC Küster, Kraatz, Schilsky: Europe's beetles - described from nature. 37th issue, Nuremberg 1900, p. 129 ( biodiversitylibrary.org ).
  15. ^ WF Erichson et al .: Natural history of the insects of Germany 5th volume, part 1, Berlin 1877 p. 189 Ennearthron cornutum.
  16. ^ Ludwig Redtenbacher: Fauna Austriaca - Die Käfer 3rd edition, 2nd volume, Vienna 1874 p. 72
  17. ^ Elzéar Abeille de Perrin: Essai monographique sur les Cesides européens & circaméditerranéens. Marseille 1874 p. 83 in the Google book search.
  18. ↑ a b Uunio Saalas: The spruce beetles of Finland 2nd volume, Helsinki 1923 Identification key of the larva , plate 1 Fig. 23 Anal segment from the side .
  19. ↑ Protocol to the post by Mellie in the meeting of the Entomological Society of 25 April 1849 the larvae of Ropalodontus perforatus and Ennearthron cornutum in Annales de la Société Entomologique de France. 2nd series, 7th volume, Paris 1849 p. XL
  20. ↑ a b Nikolay B. Nikitsky, Dmitry S. Schigel: Beetles in polypores of the Moskow region. In: Entomologica Fennica. April 29, 2004, (polyphagous in 20 species p. 14 hard fruiting bodies p. 15 entomologicafennica.org PDF).
  21. ↑ a b Johannes Reibnitz, Roman Graf, Armin Coray: Directory of the Ciidae (Coleoptera) of Switzerland with information on nomenclature and ecology in communications from the Swiss Entomological Society 86, p. 63–88, 2013 ( p. 82 No. 40 PDF) .
  22. ↑ a b Johannes Reibnitz: Distribution and habitats of tree sponge eaters in southern Germany (Coleoptera, Cisidae). In: Communications of the Entomological Association Stuttgart. P. 13 Tab. 5, PDF on ZOBODAT
  23. ↑ Bjørn Arne Rukke: Effects of habitat fragmentation: increased isolation and reduced habitat size, reduces the incidence of dead wood fungi beetles in a fragmented forest landscape . In: Ecography . tape 23 , no. 4 , August 2000, ISSN  1600-0587 , p. 492–502 , doi : 10.1111 / j.1600-0587.2000.tb00305.x .
  24. ↑ Mats Jonsell, Göran Nordlander: Field attraction of Coleoptera to odors of the wood-decaying polypores Fomitopsis pinicola and Fomes fomentarius in Ann. Zool. Fennici. 32, Helsinki, Dec. 8, 1995, ISSN  0003-455X , pp. 391-402 here p. 396 ( annzool.net PDF).
  25. ↑ Bjørn Arne Rukke: Fungivorous beetles in basidiocarps of Fomes fomentarius respond differently to microhabitat variables. In: Eur. J. Entomol. 99, pp. 43–52, 2002 ISSN  1210-5759 Height above ground, p. 45 ( eje.cz PDF).
  26. ↑ T.-E. Fossli, J. Anderson: Host preference of Cisidae (Coleooptera) on tree-inhabiting fungi in Northern Norway. In: Entomol Fennica. 9, pp. 65-78. Abstract
  27. ↑ Mats Jonsell, Göran Nordlander: Host selection patterns in insects breeding in bracket fungi . In: Ecological Entomology . tape 29 , no. 6 , 2004, ISSN  1365-2311 , p. 697-705 , doi : 10.1111 / j.0307-6946.2004.00654.x / abstract .
  28. ↑ Mats Jonsell, Clara González Alonso, Mattias Forshage, Cees van Achterberg, Atte Komonen: Structure of insect community in the fungus Inonotus radiatus in riparian boreal forests . In: Journal of Natural History . tape 50 , no. 25–26 , 2016, ISSN  0022-2933 , pp. 1613–1631 , here p. 11 , doi : 10.1080 / 00222933.2016.1145273 ( researchgate.net [PDF]).
  29. ↑ I. Hanski: Fungivori-Fungi, Insects and Ecology. In: N. Wildling, NM Collins, PM Hammond, JF Webber (Eds.): Insect-Fungus interactions. Academic Press 1989, ISBN 0-12-751800-2 , pp. 40 f. ( limited preview in Google Book search).
  30. ↑ Dmitry S. Schigel et al .: Polypores and associated beetles of the north Karelian Biosphere Reserve, eastern Finland. In: Karstenia. 44, pp. 35–56, 2004 Abstract, here pp. 54/55 (PDF).
  31. ↑ Michał Sawoniewicz: Seasonal dynamics of saproxylic beetles (Coleoptera) occurring in decaying birch (Betula spp.) Wood in the Kampinos National Park . In: Leśne Prace Badawcze (ed.): Forest Research Papers . tape 76 , no. 3 . De Gruyter Open, September 2015, ISSN  2082-8926 , p. 213-220 , here 215 , doi : 10.1515 / rp-2015-0020 ( degruyter.com [PDF]).