Two-point oak splendor beetle
| Two-point oak splendor beetle | ||||||||||||
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Two-spotted oak splendor beetle ( Agrilus biguttatus ) |
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| Scientific name | ||||||||||||
| Agrilus biguttatus | ||||||||||||
| ( Fabricius , 1777) |
| Pictures of the two-spotted oak jewel beetle | |
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| Image 1: Double side edge of the pronotum; the area enclosed by this appears a little brighter due to the lighting. |
Image 2: green: the chin process of the front chest orange: the prosternal process blue: the middle chest ocher: the back chest |
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| Photo 3: top view | |
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| Figure 4: side view. The rear hip appears club-shaped in front of the hind legs | |
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| Photo 5: bottom | |
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| Image 6: Larva (according to Reitter ) | Fig. 7: front view |
The Two Punk term oak borer ( Agrilus biguttatus ) is a beetle of the family of jewel beetle and the subfamily of Agrilinae . The slim beetle, shiny metallic green, blue or coppery, can be easily recognized by the two white dots on the wing covers. It is between eight and thirteen millimeters long.
In contrast to almost all jewel beetle species, the two-point oak jewel beetle is not specially protected by law according to the Federal Species Protection Ordinance. He is also not on any red list.
Notes on the name
A jewel beetle named Buprestis biguttata was described by both Scopoli in 1763 and Fabricius in 1776. However, the species described by Scopoli is a different beetle. The first description of Agrilus biguttatus done by Fabricius in 1776. It contains the formulation Elytra linearia, viridia terms parvo albo ad suturam ( lat. For: stretched wing covers, green with a small white dot near the elytra seam). This explains the species name biguttātus (Latin for: with two drop spots).
The genus Agrilus was established by the Englishman Curtis in 1825. He takes the name from Megerle. The explanation of the generic name Agrīlus is uncertain. Schenkling provides his explanation (from ancient Greek άγρα ágra, hunting, prey, and είλω ēīlo, to gather) with a question mark. A reference to properties of the species of the genus is not discernible.
The genus Agrilus is represented in Europe with over seventy species. Worldwide there are 36 subgenera with about three thousand species.
Description of the beetle
The head of the two-spotted oak splendor beetle is short, about three times as wide as it is long when viewed from above. The upper lip is rectangular. The upper jaws are strong, curved, pointed, cut out on the inner side with a blunt tooth. The jaw palpation has four limbs, the first limb very small, the second long and the last thickened. The lip button end link is large and club-shaped. The eleven-link antennae are short, cut inwards from the fourth link and deflected above the level of the lower edge of the eyes (Fig. 7). The eyes are large, their rear edge runs parallel and at a small distance from the lateral front edge of the pronotum. The vertical expansion is much larger than the horizontal (Fig. 1, Fig. 7).
The pronotum is much wider than it is long. As a characteristic of the species , it has a double side border. The distance between the actual lateral edge and the keel-like elevation below it is very small near the base of the pronotum and increases considerably towards the front (Fig. 1). In contrast to most species of the genus, there is no keel-like elevation above the side edge at the rear corners of the pronotum. The pronotum is deeply outlined in front of each wing cover, and shallow in front of the shield . The label is triangular, tapering at the back and has a clear transverse keel in the front third.
The front chest is slightly bent up towards the front (prosternal lobe), the front edge is not incised at an acute angle, but just outlined (Fig. 2). The extension of the front chest to the rear (Prosternal process) runs parallel between the front hips, then it tapers to a triangle. It covers the mid-breast so that it appears to be divided (Fig. 2).
The tarsi of the legs are all five-limbed, the first four tarsi are lobed. The first link of the hind tarsi is longer than the following three combined. The claws each have a tooth at the base, which is blunt and wide in the female and long and pointed in the male, so that the claws appear split. The rear hips lie broadly on the rear chest and widen outwards (image 4)
The first two of the five visible belly rings (sternites) are fused together. The abdomen is widest at about the level of the adhesions, after which it tapers uniformly. The fifth sternite is rounded at the back and has a simple edge furrow that does not bulge inwards (Fig. 5).
The elytra are long, slightly wider in front than the pronotum, then slightly inwardly outlined. In the last third they narrow evenly and at the rear end they are individually rounded and finely toothed. They are indented next to the shoulder bump and may have a rounded spot with white hair there. In the back third, near the seam at which the elytronics meet, there is an elongated rectangular field with white hairs, which is usually very clear, but can also be absent. Light hair spots can also be found on the outside of the rear hip, outside on the third to fifth sternite and on the sides of the abdomen (pleurite) except for the second and usually the fifth (Figure 4, Figure 5). Since the wing covers leave part of the abdomen uncovered at the sides, the clear white spot of the first pleuritis is particularly noticeable when viewed from above.
The male is monochrome gold-green, green or blue, the female's head and pronotum are gold-green.
Occurrence
The species occurs in deciduous forests, mainly oak forests , on forest edges, on clear-cuts and in parks. The beetles can be found on sun-exposed sticks, stumps, stored tree trunks and cordwood.
Way of life
The larvae (Fig. 6) of the two-point oak splendor beetle live in the bark of dead branches of old oaks and in their stumps. The adults also live on young oak trees.
distribution
The species is native to most of Europe. The distribution area extends in the north to southern Norway and central Sweden . It rarely appears in England . Further distribution areas are in the Caucasus , North Africa and in the anterior Asia Minor .
Natural enemies
The larvae of the two- spotted oak jewel beetle are parasitized by the parasitic wasp species Deuteroxorides elevator and the brackish wasp species Spathius erythrocephalus .
swell
Individual evidence
- ↑ Fritz Brechtel, Hans Kostenbader (ed.): The splendor and stag beetles of Baden-Württemberg . Ulmer, Stuttgart (Hohenheim) 2002, ISBN 3-8001-3526-4 .
- ↑ Red lists at BioNetworkX
- ↑ JA Scopoli: Entomologia Carniolica exhibens insecta Carnioliæ indigena et distributa in ordines, genera, species, varietates. Methodo Linnæana Vindobonae 1763 Original description on p. 103: 65 as No. 201 at GDZ
- ↑ a b JCFabricius: Genera insectorum eorumque characteres naturales secundum numerum, figuram, situm et proportionem omnium partium oris adiecta mantissa specierum nuper detectarum p. 257: 237 Description of the new species
- ↑ Sigmund Schenkling: Nomenclator coleopterologus 2nd edition Jena 1922 Explanation of the scientific beetle names (species) in short form
- ↑ John Curtis: British Entomology ... The Genera of Insects ... Vol. II Coleoptera Part II, London 1823-1840 Description of the genus Agrilus in text on Plate [50 corresponds to plate 67]
- ↑ Sigmund Schenkling: Nomenclator coleopterologus 2nd edition Jena 1922 Explanation of the scientific beetle names (genus) in short form
- ^ Agrilus at Fauna Europaea. Retrieved March 23, 2013
- ↑ Genus Agrilus at BioLib
- Jump up ↑ Jiři Zahradnik, Irmgard Jung, Dieter Jung, Jarmila Hoberlandtova, Ivan Zpevak: Beetles of Central and Northwestern Europe . Parey, Berlin 1985, ISBN 3-490-27118-1
- ↑ Nathan Brown, Daegan JG Inward, Mike Jeger, Sandra Denman: A review of Agrilus biguttatus in UK forests and its relationship with acute oak decline . Forestry. 2014. Accessed January 12, 2018.
literature
- Fritz Brechtel, Hans Kostenbader (ed.): The splendor and stag beetles of Baden-Württemberg. Eugen Ulmer Verlag, Stuttgart 2002, ISBN 3-8001-3526-4
- Wolfgang Schwenke (Hrsg.) Among others: The forest pests of Europe. A manual in 5 volumes. Volume 2: Beetles. Parey, Hamburg and Berlin 1974, ISBN 3-490-11016-1
- Fritz Schwerdtfeger : The forest diseases. Textbook of forest pathology and forest protection. 4th revised edition. Parey, Hamburg and Berlin 1981, ISBN 3-490-09116-7
- Carl Gustav Calwer and Gustav Jäger (eds.): CG Calwer's Käferbuch . K. Thienemanns, Stuttgart 1876, 3rd edition
- Heinz Joy, Karl Wilhelm Harde, Gustav Adolf Lohse: The beetles of Central Europe . tape 6 : Diversicornia . Spectrum, Heidelberg 1979, ISBN 3-87263-027-X .
- Klaus Koch : The Beetles of Central Europe Ecology . 1st edition. tape 2 . Goecke & Evers, Krefeld 1989, ISBN 3-87263-040-7 . P. 101
