Opatrum riparium
| Opatrum riparium | ||||||||||||
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Opatrum riparium |
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| Scientific name | ||||||||||||
| Opatrum riparium | ||||||||||||
| Scriba , 1865 |
Opatrum riparium is a beetle from the species-rich family of black beetles (Tenebrionidae), the subfamily Tenebrioninae and the tribe of Opatrini. The genus Opatrum occurs in almost seventy species worldwide. In Europe the genus is represented with twenty species , mostly with a small distribution area.
Comment on the name
The beetle was first briefly described by Scriba in 1865 as a distinction to the common dust beetle ( Opatrum sabulosum ), and in the two following years Gerhardt published two detailed descriptions. Scriba states that the beetle was already named Opatrum riparium by Klingelhöfer . Klingelhöfer found the beetle in the Rheingenist , that is, in the plant material washed up on the bank by the Rhine . This explains the name riparius from Latin ripārius, living on the bank, rīpa.
The genus Opátrum was established by Fabricius in 1775 and placed as the 23rd genus behind the genus Silpha . The name Opatrum has no meaning.
Properties of the beetle
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| Fig. 1: Left wing cover, red: part of the fifth wing cover interval, green: tubercle at the 5th wing cover interval |
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| Fig. 2: pronotum , dark reflective spots only clearly recognizable at higher resolution |
Fig. 3: left anterior ridge top view, left O. riparium , right O. sabulosum |
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| Fig. 4: Top view of the head, e.g. Partly colored green: left jaw palpation yellow: upper lip, left half red: head shield, left half blue: left eye, upper part |
Fig. 5: Head on the side blue: Eye brown: base links feeler gray: jaw button Arrow: transverse impression |
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Fig. 6: Head from below blue: lower part of left eye gray: left jaw button red: chin yellow: lower jaw base left dark green: lower lip light green: lip button left |
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| Fig. 7: Antenna from below, 3rd antenna section the same length as 4th + 5th combined |
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| Fig. 8: Detail of abdominal segments, left riparium , right sabulosum , white 1,2,3: 1st to 3rd abdominal sternite , white arrowhead on synovium between 3rd and 4th segment |
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The beetle, about seven millimeters in size, is black, but mostly heavily soiled and therefore mostly gray to brownish in appearance. The beetle is rather arched transversely (stronger than the species of the similar genus Gonocephalum ) and almost twice as long as it is wide.
The head is wider than it is long and widest above the protruding cheeks. The mouthparts point forward. The head shield (half tinted red in Fig. 4) is set off from the forehead by a transverse impression (black arrowhead in Fig. 5). It is rounded to triangular in front, but the incision does not extend to the side edge of the head shield and is more obtuse than in Opatrum sabulosum . The eleven-link antennae (Fig. 7) are like a string of pearls and become thicker towards the tip. Its root is covered by an upward widening of the cheeks. The antennae reach over the middle of the pronotum and are therefore relatively long. The third antenna segment is as long as the fourth and fifth together (and not shorter). The eyes (blue in Figs. 4, 5 and 6) are almost divided into two parts. As with many black beetles, the chin (red in Fig. 6) does not fill the throat, a wide slit remains at the side, which leaves the root of the jaw palpation (yellow in Fig. 6) free. The lower lip (dark green in Fig. 6) and lip button (light green in Fig. 6) are also exposed. The jaw probes are four-part with a very thick, obliquely truncated end member. The lip buttons are tripartite with a short egg-shaped end link. The short, strong upper jaws end in a two-tooth point.
The pronotum (Fig. 2) is hardly wider than the elytra on the shoulders. Towards the front it does not narrow to the middle, before that it is convexly rounded. It is not evenly grained, but has three smooth spots (mirror spots). The two front spots are symmetrical to a slightly raised and smooth longitudinal center line in the front third of the pronotum. Near the base, the midline widens to a third spot. This is smaller than the anterior spots and often divided lengthways. The base of the pronotum is moderately bulged on both sides. The deepest point of the bulge is opposite the 5th wing cover interval (position marked in red in Fig. 1). The side edges of the pronotum are bent up, especially at the front corners, while the pronotum is flattened in a narrow area in front of the side edges. The front edge of the pronotum is concave.
In Opatrum riparium the label is less dotted and less densely dotted. It is largely hairless and therefore more shiny than the label on Opatrum sabulosum .
The wing covers (Fig. 1) are barely broadened in the middle and end together round. They are extremely short haired. The wing cover seam and the uneven spaces between the wing covers (the 5th in Fig. 1 indicated in red) are raised like ribs. The ribs shine clearly near the seam, becoming increasingly matt on the outside. In addition to the rib-shaped raised intervals, there are rows of tubercles on each side (in Fig. 1 a single tubercle tinted green). The tubercles are more oval and less round, and per row clearly less numerous than in Opatrum sabulosum , often only six to seven. They can merge with the ribs or also bridge them so that the ribs appear zigzag. In between, the wing covers are evenly fine-grained. The folded part of the wing-coverts forms fake epipleurs that end at the shoulder angle.
The front splints widen towards the tarsi , the outer corner is drawn out into a terminal mandrel (black arrow in Fig. 3 left). This is much more strongly developed than in Opatrum sabulosum (Fig. 3 right), in which the enlargement forms a triangular shape. The rails of the middle pair of legs are slightly widened towards the tip on both sides, the inner tip of the male is much more enlarged than that of the female. The tarsi of the rear legs are four-limbed, those of the other five-limbed. The tarsi are bristled with spines. The front tarsi in the male are not expanded compared to the females and are not brushed below.
The underside of the fore chest is less widened behind the front hips than in Opatrum sabulosum . Between the third and fourth abdominal segment (also between the fourth and fifth segment) there is a difference in height that is bridged by a shiny synovial membrane (white arrow in Fig. 8, left). On the underside, the first three abdominal segments (abdominal sternite) are irregularly and finely wrinkled lengthways (Fig. 8 left). The wrinkles are relatively long and sometimes extend from the anterior to the posterior edge of the segment, while they are significantly shorter in Opatrum nebulosum (Fig. 8 right). In the male, the first two abdominal segments are traversed in the middle by a shallow longitudinal impression. This reduces the risk that the males slip sideways when riding on the females.
biology
The beetle can be found on the sandy banks of large rivers, also on sandy meadows and fields near the banks and on dry bog areas. They can be found there under stones, on washed up things, between the grass and often on freshly raised molehills.
distribution
The species is only known from Central Europe ( Denmark , Germany , Austria , Czech Republic ) and parts of Northern Europe ( Norway , Sweden , Finland , Estonia , Lithuania ) and Eastern Europe ( Hungary , Poland , Slovakia , northwestern Russia ). The beetle is also reported from France ( Alsace ).
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 . P. 243
- Klaus Koch : The Beetles of Central Europe Ecology . 1st edition. tape 2 . Goecke & Evers, Krefeld 1989, ISBN 3-87263-040-7 . P. 337
- Gustav Jäger (Ed.): CG Calwer’s Käferbuch . K. Thienemanns, Stuttgart 1876, 3rd edition p. 623
Individual evidence
- ↑ a b Opatrum riparium and Opatrum at Fauna Europaea, accessed on April 5, 2019
- ↑ a b W. Scriba: The beetles in the Grand Duchy of Hesse and its immediate surroundings . In the eleventh report of the Upper Hessian Society for Nature and Medicine, Giessen 1865, page 1-59 Opatrum riparium, p. 50 in the Google book search
- ^ A b J. Gerhardt: Opatrum riparium (Klingelh.) Scriba . In German Entomological Journal 1896, Issue II pp. 383-511 [1] and even more detailed in 1897 in Zeitschrift für Entomologie [2]
- ↑ Sigmund Schenkling: Explanation of the scientific beetle names (species)
- ^ Johann Christian Fabricius: Systema entomologiae, sistens insectorvm classes, ordines, genera, species, adiectis synonymis, locis, descriptionibvs, observationibvs Flensburg, Leipzig 1775, p. 76
- ↑ Sigmund Schenkling: Explanation of the scientific beetle names (genus)
- ↑ G. Vorbringer: Collective report from East Prussia for the year 1906 (Col) in German entomological journal, year 1907, 4th issue, p. 418 f. Pp. 818/819
- ^ Henry Callot, José Matter: Opatrum riparium Scriba 1865 nouvelle espèce pour la faune de France (Coloeptera Tenebrionidae) . In L, Emntomologiste tome 62, No 1-2 [3]
