Unequal furrow hawk beetle
| Unequal furrow hawk beetle | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Unequal furrow hawk beetle |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Rhysodes sulcatus | ||||||||||||
| ( Fabricius , 1787) |
|
|
| Fig. 1: Top view | Fig. 2: Head from the front |
|
|
| Fig. 3: side view | Fig. 4: Head and breast shield |
|
|
| Fig. 5: Bottom |
Fig. 6: A: lower jaw B: upper lip C: upper jaw |
The unequal furrow beetle ( Rhysodes sulcatus ) is a beetle from the family of the wrinkle beetle (Rhysodidae). The worldwide widespread genus Rhysodes is only represented in Europe by the species Rhysodes sulcatus , since the former species Rhysodes germari is now known as Omoglymmius germari . Overall, the wrinkle beetles are represented in Europe with only three species, which differ significantly in the furrowing of the pronotum.
The generic name Rhysodes (from ancient Greek ρυσώδης “rhyssōdes” for “wrinkled”) and the species name sulcātus ( Latin for furrowed) refer to the noticeable furrows on the head and pronotum. The species is listed in Appendix II of Directive 92/43 / EEC (Fauna-Flora-Habitat Directive) .
Characteristics of the beetle
The elongated beetle becomes around seven millimeters long. The head and pronotum are distinctively grooved. The entire body is shiny reddish brown.
The triangular head points forward. At the widest point are the eyes on the side. They are composed of relatively few individual eyes and therefore appear roughly faceted. At the back the head is clearly constricted to a neck. The mouthparts are covered at the bottom by the three-toothed chin, only the tips of the yellowish buttons protrude above the outline of the head. The eleven-link antenna consists of spherical links of roughly the same size, only the end link is egg-shaped and pointed. They are turned on the side of the head. The top of the head is divided into a cheek-shaped elevation above the eyes and an elongated central callus by two deep furrows that are widened like a pit in the middle.
The bell-shaped pronotum (Fig. 4) is slightly wider at the front than the neck, at the back as wide as the base of the wing cover, the greatest width being about halfway up. The three European representatives of the wrinkle beetle can be clearly distinguished by its distinctive grooves. In the uneven furrow beetle, the middle furrow extends from the base to the front edge of the pronotum and widens there slightly. There is a parallel furrow on either side of the central furrow. In Rhysodes sulcatus this begins broadly at the base of the pronotum and tapers in the front half of the pronotum. In Omoglymmius germani, on the other hand, it is much longer, about as long as the central furrow. In Clinidium canaliculatum , the lateral furrows are short.
The sides of the elytra are mostly parallel, the shoulders are rounded. At the end, the wing-coverts are rounded together approximately in a semi-circle. They have seven rows of rough round dots , the spaces in between form ribs. At the end of the wing cover there is another shortened row of points above the seventh row of points from the beginning of the wing cover curve. The label is very small.
The hips of all three pairs of legs are widely separated (Fig. 5). The legs are short and strong, the narrow tarsi all five-limbed. The first four links are the same size and relatively small, the claw link is even weaker, the claws are imperforate. Six abdominal segments can be seen from below. The first is only partially visible between and next to the rear hips, the first to third abdominal sternite fused together and only separated from each other by an indistinct seam. The males' rear rails are serrated at the top.
biology
The species develops in old standing or lying dead deciduous and coniferous trees with high humidity, especially oak and beech . It is classified as a pointer species for a stable, original mixed forest with a high proportion of dead wood . The new adults can be found in Poland in late July and August. Then they crawl under bark or in the feeding passages of other wood insects.
Mating and oviposition take place in the following spring. The larvae feed on rotting wood (saproxylophag). Pupation takes place in July. The doll's cradle is lined with thin and short wood fibers. The moult to the imago takes place after two to three weeks. The development is probably two years.
Hazard and protection
The occurrence of the species is strongly declining. The reason one sees the extensive removal of old and dead wood from commercial forests. Accordingly, it is recommended to leave standing and lying dead wood in the forest, especially in areas where the beetle was found. In the core area, smaller trees should be temporarily removed to improve the light.
distribution
Of the three European species of the subfamily Rhysodinae, the unequal beetle is most widespread here. Most of the reports are old and the habitat of this jungle relic is becoming more and more restricted. The species is reported from Spain to the south of the European part of Russia, but is absent in Great Britain , the Benelux countries , Denmark , Norway , some Central European ( Switzerland , Austria ) and most of the southern European countries.
literature
- Edmund Reitter : Fauna Germanica, the beetles of the German Empire I. Volume, KGLutz 'Verlag, Stuttgart 1908
- Heinz Joy, Karl Wilhelm Harde, Gustav Adolf Lohse: The beetles of Central Europe . tape 2 . Adephaga 1. Elsevier, Spektrum, Akad. Verl., Munich 1976, ISBN 3-87263-025-3 .
- Wilhelm H. Lucht, Bernhard Klausnitzer: The beetles of Central Europe . Ed .: Heinz Freude (= Käfer Mitteleuropas . Volume 15 ; 4th supplement band). Gustav Fischer / Goecke & Evers, Jena / Krefeld 1998, ISBN 3-437-35366-7 .
- Gustav Jäger (Ed.): CG Calwer’s Käferbuch . K. Thienemanns, Stuttgart 1876, 3rd edition
Web links
Individual evidence
- ↑ Edmund Reitter : Fauna Germanica, the beetles of the German Empire, Volume I, KGLutz 'Verlag, Stuttgart 1908
- ↑ Rhysodes at Fauna Europaea. Retrieved September 9, 2012
- ↑ Omoglymmius germari in Fauna Europaea. Retrieved September 9, 2012
- ↑ Sigmund Schenkling: Explanation of the scientific beetle names (genera)
- ↑ Sigmund Schenkling: Explanation of the scientific beetle names (species)
- ↑ a b Paweł Sienkiewicz: Rhysodes sulcatus (Fabricius, 1787) Polska czerwona księga zwierząt as PDF
- ↑ M. Jurc, N. Ogris, R. Palvin D. Borkovic: Forest as a Habitat of saproxylic Beetles on Natura 2000 sites in Slovenia as PDF ( page no longer available , search in web archives ) Info: The link was automatically marked as defective . Please check the link according to the instructions and then remove this notice.
- ^ Official website of the Czech Ministry of Agriculture
- ↑ Rhysodes sulcatus in Fauna Europaea. Retrieved September 9, 2012
