Red head beetle
| Red head beetle | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Fig. 1: Red ear beetle, autumn ear beetle |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Anthocomus rufus | ||||||||||||
| ( Autumn , 1786) |
The red flag beetle ( Anthocomus rufus , syn .: A. coccineus ) is a beetle from the family of the flag beetle . The beetle, which is just under five millimeters tall, can be found on flowering reeds in autumn . That is why it is also called the autumn tip beetle . You can also find the name of the red warthog beetle .
Notes on the name
The species was described under the name Malachius rufus in autumn 1786 . Schaller had already described the species under the name Cantharis coccineus in 1783 . Both coccineus ( Latin scarlet red) and rufus (Latin red) refer to the color of the elytra and the pronotum.
The genus Malachius, which was established by Fabricius in 1785 , Erichson separated into numerous genera in 1840, to which Anthocomus also belonged. The generic name Anthocomus ( old Greek ανθοκόμος anthokómos) means looking after flowers and stands for colorful beetles.
The genus Anthocomus is represented by ten species in Europe and around fourteen species worldwide.
Characteristics of the beetle
The elongated body has a weakly sclerotized exoskeleton . It is indistinctly hairy and reaches an average length of almost five millimeters.
The elongated black head is tilted slightly downwards. The mouthparts point forward (Fig. 2). The upper jaws have a two-tooth tip. The thread-like jaw probes are tripartite, the end link is spindle-shaped and ends with a point (Fig. 5). The lip buttons are short, the second and third links are the same length. The eleven-link antennae are thread-shaped. They arise in front of the eyes, not in between.
The pronotum is wider than it is long. At the base it is finely edged and tapers rounded. It is black and red or red on the sides with a wide black central stripe. Red and black are not sharply delimited against each other, but merge smoothly into one another.
In the female, the wing covers only incompletely cover the abdomen. They are only a little wider than the pronotum. The double hairs, which are common within the family, are missing: the elytra are only hairy, fluff-like. They are the same red as the edges of the pronotum. A fuzzy black spot usually appears around the tag . In the female the elytra are slightly widened to the rear, in the male they run almost parallel. At the tip of the elytra in the male there is a conspicuous structure called an excitator (Fig. 4). It consists of a black, intricately curved chitin strip, reminiscent of a clef, on each grand piano. The chitin strip ends in an upward or backward tuft of hair (whitish in Fig. 4), at the base of which a secretion emerges. The secretion that emerges in the head of hair is absorbed by capillary action. The head of hair is presented in front of the female's oral cavity when it is positioned behind the male. Additional pore fields on the outer edge and at the tips of the elytra correspond to the position of the jaw buttons and the lip buttons of the female in the same position.
The abdomen has six segments, the last ( pygidium ) is slightly bulged.
The legs are long and slender, the tarsi five-limbed. The claws enable a secure hold even on swaying plants
 Fig. 2: top |
 Fig. 4: Excitator at the end of the wing covers (shrunk dead material) |
 Fig. 3: side view |
|
 Fig. 5: Front view |
biology
The animals are diurnal and love the sun and the warmth. The beetles eat pollen from the reeds ( Phragmites communis ). Dead insects are also eaten, preferably prey of the reed spider .
The beetles can often be found en masse on the host plant and also mate there. The pairing is usually preceded by a so-called taste beating (gustatory courtship), as it can only be found in the group beetles .
The taste of the autumn flag beetle differs from that of other malachiids . When the animals are not busy eating, both males and females run around searching. A conspecific is only recognized as such at a short distance and its sex is registered. A female can run up against a male from behind on the stalks, a male can overtake a female, or both can meet head-on.
In the simplest case, the female runs towards the rear end of the male. Then it is not uncommon for this to simply sit still or to push backwards towards the mouthparts of the female. If, on the other hand, the male is behind the female, then the former touches the partner's abdomen with its feelers and both rotate 180 degrees so that the end of the male's body is in front of the female's head.
In contrast to related species, probe contacts are rare when they come face to face. Such a meeting is aggressive. If such probe contacts occur in kind, they are short. A subsequent turn of the male by 180 ° is not a jerk, but a slow U-turn.
In all three cases the so-called "nibbling position" is achieved in which the male rear end with the excitators is in front of the female mouthparts. The female's jaw and lip probes pick up the smell of the corresponding secretory fields on the male's wing covers, the tuft of hair reaches the female's mouth and is nibbled by it.
The female does not bite violently into the excitator as with related species, but the nibbling takes place "with relish" and sometimes takes longer than two minutes. Only in exceptional cases does the female caress the end of the male body with one or both front legs. The movements of the male's hind legs, presumably derived from defensive movements, also proceed without haste. The hind legs, which circle in a characteristic way, occasionally touch the head of the female. At the same time, the male abdomen swings leisurely up and down. Here, females and males get into copulation mood.
As a special feature, a role reversal can be observed in the autumn flag beetle. The male nibbles on the ends of the female's wing covers while doing circular movements with the hind legs. In this case, the irritation is only tactile.
During copulation, the male rides only incompletely by holding onto the edge of the wing of the females with its middle legs. After a while the male folds his front body backwards and the couple takes the position known from the cockchafer. The copulation time is a maximum of about 10 minutes. The animals break away from each other by pushing each other with their hind legs. The copulation can also take place without previous nibbling.
The type and location of the egg-laying are still unknown.
Distribution and occurrence
The species is only found to a limited extent in Europe. In the north they are found in Sweden , but not in Finland . In the west it occurs in England , France , Spain and Portugal , but is absent in the Benelux countries . In the east, the border of the distribution area runs through Poland , Slovakia , Hungary , Austria and Italy .
Even within its range, the occurrence of the species is not extensive, but is limited to swampy areas.
literature
- H. Joy, KW Harde, GA Lohse: Die Käfer Mitteleuropas , Vol. 6. Spectrum Academic Publishing House in Elsevier, Munich 1966, ISBN 3-827-40683-8
- Gustav Jäger (editor): CG Calwer 's Käferbuch . K. Thienemanns, Stuttgart 1876, 3rd edition
- Matthes, D., 1971: The sexual behavior of the Malachiid Anthocomus (Anthocomus) coccineus Schall. (Coleoptera, Malacodermata) Zeitschrift Tierpsychol. 9 (2): 113-120
Individual evidence
- ↑ a b Systematics, synonyms and distribution of the red flag beetle
- ↑ JFW Herbst: Critical Directory of my Insect Collection Archive of Insect History 4, 5 1783-1784 First description of the species, page 108
- ↑ WF Eichson: Entomographien, studies in the field of entomology Berlin in 1840 at BHL
- ↑ Sigmund Schenkling: Explanation of the scientific beetle names (genus)
- ↑ Anthocomus in Fauna Europaea. Retrieved March 20, 2013
- ↑ Species of the genus Anthocomus at BioLib
- ↑ a b Matthes, D., 1971: The sexual behavior of the Malachiid Anthocomus (Anthocomus) coccineus Schall. (Coleoptera, Malacodermata) Zeitschrift Tierpsychol. 9 (2): 113-120
- ↑ Pictures of the consumption of animal food, French page
- ↑ Picture with the inclusion of animal food, photo community
