Onthophagus verticicornis

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Onthophagus verticicornis
Onthophagus verticicornis, female

Onthophagus verticicornis , female

Systematics
Order : Beetle (Coleoptera)
Subordination : Polyphaga
Family : Scarab beetle (Scarabaeidae)
Subfamily : Scarabaeinae
Genre : Onthophagus
Type : Onthophagus verticicornis
Scientific name
Onthophagus verticicornis
( Laicharting , 1781)
Onthophagus verticicornis male.jpg Onthophagus verticicornis female.jpg
Fig. 1: Head male,
forehead ridge weak,
crown ridge as horn 		Fig. 2: Female head,
forehead and crown-
shaped ridges
Onthophagus verticicornis detail.jpg
Onthophagus verticicornis under.jpg
Fig. 3: Rasp-like puncturing of
the pronotum
(left = front, bottom = side) 		Fig. 4: Underside,
partially colored on the right:
moving thorn green

Onthophagus verticicornis (also Nodding pill beetle ) is a beetle from the family of scarab beetles (Scarabaeidae) and the subfamily Scarabaeinae . The genus Onthophagus is represented in Europe with six subgenera . Inaddition to Onthophagus verticicornis , thesubgenus Palaeonthophagus containsanother 35 species . The name Onthophagus verticicornis was also given to another species by Fabricius in 1775. This was already described by Linné in 1758 as Onthophagus nuchicornis and is thereforealso calledthat today according to the priority rule . For Onthophagus verticicornis (Laicharting 1781) six synonyms are listed.

The scientific generic name Onthophagus means " dung eater" (from ancient Greek ὄνθος "ónthos", "(cow) dung" and φάγος "phágos", "eater"). The species name verticicornis ( lat. Vértex "top" and córnu "horn") can be explained by the fact that the males wear a horn on the top.

Characteristics of the beetle

The usually black beetle is seven to ten millimeters long. It has an oval shape, with the hind legs, which are turned far back, that stand out (Fig. 4).

The head is sparsely hairy and thus enables it to be differentiated from the very similar species Onthophagus sericatus . The head shield is almost trimmed. It completely covers the mouthparts . In the female (Fig. 2) it is slightly bent up at the front edge, in the male (Fig. 1) it is slightly pulled forward and more bent up. The thread-like jaw buttons are four-part (clearly visible in Fig. 1 and 2), the lip buttons are three-part. The head has two cross bars, the front bar and behind it the top bar. The forehead ridge is only weakly developed in the male. In the male, the apex bar is drawn out backwards into a triangular lamella, which protrudes over the rear edge of the head and the front edge of the pronotum and ends in an approximately vertical, slightly forward curved or undulating horn. In the female, the forehead ridge protrudes sharply upwards, the apex bar has the shape of a bar that is only moderately high and barely sloping backwards. The antennae are nine-parted and end in a three-leaved club. The majority of the eyes are on the underside of the head, the view upwards is only possible through a slit-shaped opening (Fig. 2 and 4).

The most forward raspelartig dotted pronotum (Fig. 3) bulges out the front edge hump-like and before that drops steeply. In the male, the hump is clearly hollowed out to accommodate the horn. In the female, it has two flat, forward-facing elevations at the highest point next to the middle (Fig. 2). In both sexes, the pronotum is bristly haired and laterally rimmed. Behind the anterior angles, the pronotum is flared, so that it appears to be lengthened to the front like a lobe.

The usually black wing-covers can have one or two red-brown spots in the shoulder area or they can also be completely red-brown in color. They are finer and darker hairy than the pronotum. You have eight point hoops, the eighth is close to the sidebar. A row of dots runs between the first dotted strip and the sash seam, and three each between the following dotted strips. The label is not visible. The wing covers release part of the pygidium . The base of the pygidium is finely edged like a strip.

The front legs are transformed into grave legs. The front rails have four strong teeth on the outer edge. The tip of the splint is truncated at an angle, so the foremost outer tooth is directed a little forward. There is a movable mandrel on the inside of the rail tip. The middle rails have two very unequal sized end pins, the rear rails a mighty end pin (Fig. 4, right tinted green or yellow). The middle and rear rails suddenly end widened towards the tip. The tarsi of all legs are five-limbed. The tarsi of the foreleg are particularly thin. The thighs, splints and tarsi of the hind legs are considerably longer than those of the middle pair of legs. The middle hips are widely separated and parallel to each other, the rear pair of legs is pivoted far back on the body (Fig. 4).

biology

The species can be found both on meadows and in the forest ( eurytop ). It feeds on manure and is classified as a generalist on nutrition. In a study in southern Germany, sheep dung was slightly preferred to cow dung, whereas in a collection in Spain five out of nine finds came from goat dung and four from horse dung. The beetle also likes to take on the solution of game and human excrement, and beetles have also been observed on tree sap

The onthophagus species belong to the feces-eaters, in which the female digs a species-specific system of main and secondary tunnels into the earth to lay eggs. The eggs are placed in brood chambers. Together with the male, manure is then introduced into the breeding chambers as food for the larvae.

In an investigation in southwest Germany ( Kaiserstuhl ) the beetle appeared in April and quickly reached its first frequency maximum. After that, its frequency decreased until mid-June, reaching a second maximum in late June and early July. Since the development of the examined species of the genus Onthophagus takes between 35 and 42 days, this could speak for two generations of the species per year.

distribution

The species is distributed from Portugal to the Caspian Sea , but is absent in northern and northeastern Europe.

literature

Individual evidence

  1. ↑ Heiko Bellmann: The new cosmos insect guide . Franckh-Kosmos Verlag GmbH & Co., Stuttgart 1999, pp. 174-175, ISBN 3-440-07682-2
  2. ↑ a b c Onthophagus verticicornis in Fauna Europaea. Retrieved September 20, 2012
  3. ^ Onthophagus in Fauna Europaea. Retrieved September 20, 2012
  4. ↑ Palaeonthophagus (subgenus) in Fauna Europaea. Retrieved September 20, 2012
  5. ↑ Onthophagus nuchicornis at Fauna Europaea. Retrieved September 21, 2012
  6. ↑ Sigmund Schenkling: Explanation of the scientific beetle names (genus).
  7. ↑ Sigmund Schenkling: Explanation of the scientific beetle names (kind).
  8. ↑ Thomas Wassmer: Selection of the spatial habitat of Coprophagus beetles in the Kaiserstuhl area near Freiburg (SW-Germany). In: Acta Oecologica. 16 (4), 1995, pp. 461-478 as PDF
  9. ↑ E. Galante, J. Rodríguez-Romo, M. García-Román: Distribución y actividad anual de los Onthophagini (Col. Scarabaeidae) en la provincia de Cáceres (España). In: Boletín Asoc. esp. Entom. Vol. 12, Salamanca, November 1989, pp. 333-352. as PDF
  10. ↑ Klaus Koch : Die Käfer Mitteleuropas Ökologie . 1st edition. tape  2 . Goecke & Evers, Krefeld 1989, ISBN 3-87263-040-7 .
  11. ↑ Heinz Freude , Karl Wilhelm Harde , Gustav Adolf Lohse (ed.): Die Käfer Mitteleuropas (=  Käfer Mitteleuropas . Volume  1 : Introduction to Beetle Science ). 1st edition. Goecke & Evers, Krefeld 1965, ISBN 3-8274-0675-7 .
  12. ^ Adolf Horion : Käferkunde for nature lovers . Vittorio Klostermann, Frankfurt am Main 1949.
  13. ↑ Thomas Waßmer: Seasonality of Coprophagus beetles in the Kaiserstuhl area near Freiburg (SW-Germany) including the winter months. In: Acta Oecologica. 15 (5), 1994, pp. 607-631. as PDF
  14. ↑ Carmen Huerta, Imelda Martínez, Mercedes García-Hernández: Preimaginal Development of Onthophagus incensus Say, 1835 (Coleoptera: Scarabaeidae: Scarabaeinae). In: The Coleopterists Bulletin. 64 (4), 2010, pp. 365-371. doi: 10.1649 / 0010-065X-64.4.365

Web links

Commons : Onthophagus verticicornis  - album with pictures, videos and audio files