Akis elongata

Akis elongata
Akis elongata male on a rock face
Systematics
Class : Insects (Insecta) Order : Beetle (Coleoptera) Family : Black beetle (Tenebrionidae) Subfamily : Pimeliinae Genre : Akis Type : Akis elongata
Scientific name
Akis elongata
Brullé , 1832

Akis elongata is a beetle from the family of the black beetle (Tenebrionidae) and the subfamily of the Pimeliinae . It occurs only in south-east Europe. The genus Akis is represented in Europe with twelve species .

Comment on the name

The genus Akis was separated from the genus Pimelia by Herbst in 1799 . Herbst does not comment directly on the naming, and the name Akis is not mentioned in Schenkling's explanations of the beetle names . But Herbst formulates the description of the genus: The breastplate distinguishes this genus most clearly, ... hence (why) the side corners protrude sharply pointed . And ancient Greek άκις (akis, grammatical gender female) means arrow or spearhead. The corners of the breast shield and especially the back corners of the males of Akis elongata are quite comparable to the point of a throwing weapon.

The species Akis elongata is one of the numerous insect species that were first described by Brullé in 1832 as a result of the Morea expedition . The Latin description begins with the words elongata, nigra ( Latin for elongated, black). The species name elongata refers to the body shape of the black beetle, which is more elongated than other species of the genus.

The species Akis elongata was described by Waltl in 1838 as Akis deplanata (from Latin deplanātus, flattened, named after the flat wing-coverts ). The forms opaca (from Latin opācus, dark, matt, because of its different body color) and taygetana (named after its occurrence in the Taygetos mountains ) were at times regarded as subspecies of Akis elongata , but today they are only classified as synonyms because there is between gives the shapes flowing transitions.

Properties of the beetle

Fig. 1: Male (♂)
Fig. 2: Females (♀) eating
Fig. 3: base of pronotum ♂
Fig. 4: Left anterior tarsus from outside	Fig. 5: Sensor tip from below
Fig. 6: Puncture on the head (C), pronotum (P) and wing covers (E)
A. B.
C.	Fig. 7: Head A from the front B from below C partially colored on the side (right side)
yellow: front corner of the pronotum, green: antennae, dark blue: upper lip, red: upper jaw, blue: jaw button, pink: lip button, ocher: chin, white arrowhead: eye keel

The robustly built beetle is usually twenty to twenty-two millimeters long and nine to ten millimeters wide. It is black, slightly shiny to matt.

The head is directed forward and retracted into the pronotum. It is noticeably uneven. It is a little longer than it is wide. The upper lip (Fig. 7A, right half, dark blue) is significantly wider than it is long, the strongly chitinized part at the front slightly cut out, very finely dotted with rounded corners. The mighty upper jaws (Figs. 7A, B, C outlined in red and tinted) end with two tips (clearly visible in Fig. 7B). The eleven-part antennae are not round, but rather slightly compressed across the width. They are smooth, with a few deep points on each antenna link and with a few short bristle hairs at the tip. The second link is hardly longer than wide, the third link is almost two and a half times as long as the fourth. After that, the feeler links become increasingly shorter, especially the last three links are short. The last antenna segment is pointed at an oblique angle, the tip is densely covered with sensory cells and thus appears brownish and matt (Fig. 5). The antennae do not reach the elytra. The head shield is deeply edged and extended and bent up on the sides above the antennae roots (Figs. 7A and 7C). The eyes are very shallow and very short, but a good three times as wide as they are long. The folding of the head skeleton in the area above the eyes (eye keel), which is characteristic of the genus, is only weakly developed in Akis elongata (Fig. 7C, white arrowhead). The chin (Figs. 7A and 7B ocher-colored) is heart-shaped, relatively flat and hides the lower lip. Only the tips of the three-part lip stylus are visible (Fig. 7 pink). The black four-part jaw buttons (Fig. 7 blue) are reddish at the tip like the lip buttons. The chin does not completely fill the neckline of the head, and there is a clear gap on the sides of the chin.

The puncture of the head and the pronotum is fine and relatively dense (Fig. 6, head C and pronotum P). The pronotum is approximately heart-shaped. It is strongly cut out in front, enclosing the head up to the eyes. At the base, however, it is only very slightly concave. The side edges are broadly bent up, rounded and broadened, narrowing towards the rear. The front angles in the male (Fig. 1) are slightly more acute than in the female (Fig. 2), and in both sexes are bluntly rounded. The rear angles are pointed, thorn-shaped in the male. The base of the pronotum in the male is marked by an indented transverse line between the posterior angles (Fig. 3). Halfway along the pronotum is slightly arched transversely, several shallow and finely dotted impressions run along its length, and near the side edges there are irregular, transverse to radiant wrinkles. The pronotum does not close closely to the elytra.

The label is triangular, smooth and protruding slightly upwards at the tip.

The elytra are oval and significantly wider than the pronotum. At the base and at the end the wing covers are steeply sloping, at the end they are pointed and rounded off together. The back of the wing covers is very flattened and without ribs. The part of the elytra, viewed from above, appears as the outer edge, however, is characterized by a clear, fine rib (lateral rib). This can be more or less notched. In females, the lateral rib is often unnotched, but the intensity of the indentation does not give a reliable indication of the sex of the animal. The wide, vertically sloping false epipleures run directly to the outside of the lateral rib. Narrow real epipleurs, which reach up to the wing tip, close off the wing covers laterally.

The elytra are scattered and far less dense than the head and breast shield, irregularly distributed, and very flat points (Fig. 6E), also isolated flat wrinkles that run in different directions.

The front legs are not noticeably thickened. With the exception of the claw segment, the tarsi are narrow, the segments higher than they are wide (Fig. 4). The hind tarsi are four-limbed, the remaining tarsi five-limbed.

The beetle is very finely dotted underneath.

biology

The beetles live in warm and humid locations. A source mentions the preference for dark places, a find report names a small dry cave as the location. The animals feed on decomposing organic substances, Figure 2 shows a beetle eating bird droppings, Brullé mentions the occurrence on human excrement.

In a standard work on stored food pests, the occurrence of the beetle in grain mills is mentioned and wheat , wheat flour, barley , maize and hay are listed as affected commodities . However, the species is classified in the category of insects, which can only be found in the stores, damage is not mentioned and no information on the biology of the beetle is given.

distribution

The species shows an Eastern Mediterranean distribution ( Albania , Greece with the Greek islands, Cyprus , Macedonia , Bulgaria and European Turkey ). It is unclear how far the species penetrates eastward in Turkey.

literature

Gustav Jäger (Ed.): CG Calwer's Käferbuch. K. Thienemanns, Stuttgart 1876, 3rd edition, p. 636

Individual evidence

1. ↑ ^{a b} Akis elongata from Fauna Europaea, accessed on September 16, 2018
2. ^ Friedrich Wilhelm Herbst: Natural system of all domestic and foreign insects of the beetles VIII. Theil, Berlin 1799 p. 125, 85. Akis genus in the Google book search
3. ↑ Sigmund Schenkling: Explanation of the scientific beetle names (genus)
4. ↑ Edward Maltbe: A new and complete Greek Gradus ... London 1830 Ἄκις page 28 in the Google Book Search
5. ^ ^{A b} M. Brullé: Expédition scientifique de Morée Tome 3, Zoologie, 2nd Section Paris 1832 p. 194, no. 339 in the Google book search
6. ↑ ^{a b c} Sigmund Schenkling: Explanation of the scientific beetle names (species)
7. ↑ Waltl: Additions to the knowledge of the Coleoptera of the Turkey in Isis - Encyklopädische Zeitschrift Heft VI. Leipzig 1838 Akis deplanata p. 461
8. ↑ ^{a b c} Wolfgang Schawaller: Revision Westpaläarkticher Tenebrionidae (Coleoptera) Part 1: The species of the genus Akis Herbst. in Stuttgart Contributions to Natural History Series A (Biology) No. 403, Stuttgart December 1, 1987 Akis elongata p. 7
9. ^ G. Kraatz: Revision of the Tenebrioniden of the old world .... Berlin 1865 Akis elongata p. 251
10. ↑ HC Küster: The Beetles of Europe - described from nature 14th issue, Nuremberg 1848 Akis elanongata without page number
11. ^ M. Solier: Essai sur les Colaptérides in Annales de la Société entomologique de la France 5th volume Paris 1836 Akis elongata p. 659
12. ↑ ^{a b} Chronica - Annales de l'Institut phytopathologique Benaki, Volumes 13-15, Athens 1981
13. ↑ Victor Apfelbeck: Report on an entomological research trip to Turkey and Greece in 1900 in Scientific reports from Bosnia and Hercegovina VIII: Volume, Vienna 1902 p. 457 Site in cave
14. ↑ David W. Hagstrum, Bhadriraju Subramanyam: Stored-Product Insect Resource Elsevier, June 20, 2016, Chapter 1, p. 8

Web links

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