Two-spotted awl runner

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Two-spotted awl runner
Two-spotted awl runner

Two-spotted awl runner

Systematics
Class : Insects (Insecta)
Order : Beetle (Coleoptera)
Family : Ground beetle (Carabidae)
Subfamily : Trechinae
Genre : Philochthus
Type : Two-spotted awl runner
Scientific name
Philochthus biguttatus
( Fabricius , 1779)

The two- spotted Ahlenläufer ( Philochthus biguttatus , Syn .: Bembidion biguttatum ), also called the Great Marsh Ahlenläufer , is a ground beetle from the subfamily Trechinae .

The species is classified as not endangered in the Red List of Endangered Species in Germany and in the states of Baden-Württemberg and Saxony-Anhalt .

Notes on the name

The species was first described by Fabricius in 1779 under the name Carabus biguttatus . The description contains the characterization macula apicis pallida ( lat. The spots at the end of the elytra are pale). The number of these spots is expressed in the species name biguttatus (Latin "with two drop spots") and in the addition "two spots" to the German name. However, there are several similar species that also have two points on the elytra, on the other hand the spots can also be missing.

The generic name Philochthus is from ancient Gr . φίλος phílos "friend" and ὄχθος óchthos "hill" derived and indicates that the species can be found on mountains under stones. However, this is less true of this species.

The genus Philochthus was not established until 1828. It contains eighteen species that are all found in Europe.

Front view
Fig. 1: Front view
shoulder
Fig. 2: shoulder
head
Fig. 3: Head Fig. 4: Pronotum
Pronotum
Wing cover
Fig. 5: Wing cover, base on the left
green: end of the seventh dot stripe
yellow arrow: missing edge
blue arrow: front bristle point in the third interval
bottom
Fig. 6: Bottom

Characteristics of the beetle

The black beetle grows to around four millimeters. The first link of the thread-shaped eleven-link feeler , the legs and some of the buttons are amber.

The mouthparts point forward, the end links of the jaw probes sit like a pin in the club-shaped thickened penultimate link. (Name Ahlenläufer, Fig. 1). This feature distinguishes all species of the Bembidiini tribe , which is why they were previously listed as the subfamily Bembidiinae. The forehead is furrowed lengthways next to the eye rims. The longitudinal furrows encompass two pore points above each eye , in which the two bristles above the eye (supraorbital ligament) arise (Fig. 3).

On the side edge of the slightly arched pronotum there are two bristle points on each side, the first in front of the half, the second near the base of the pronotum (Fig. 4, black arrowheads on the right). The side edges are evenly bent outwards up to the rear bristle point, and the two rear bristle points are about the same distance apart as the pronotum front edge is wide. Behind the second bristle point, the pronotum is tied off in a concave, neck-like manner. The posterior angles are obtuse but distinct (Fig. 2).

The wing covers have a short row of dots next to the label and seven further rows of dots that become indistinct towards the end. The outermost row of dots (Fig. 5, highlighted in green on the right) is only slightly weaker than the one next to it. Towards the end the wing covers are lightened brownish and each wing cover bears a yellowish spot (pre-apical spot) before the end. Of the two pore points in the third interval, the front one lies in front of the middle of the wing cover (Fig. 5, blue tinted arrow). At the end of the wing there is no keel in the eighth furrow (Fig. 5, yellow-tinted arrow). The side edge of the wing cover does not bend backwards at the base (Fig. 2 and 5).

biology

The moisture-loving species occurs regularly in Central Europe in muddy places in arable fields or grassland, mainly after heavy rainfall, which explains the name "Marsh Ahlenläufer". The beetles are most common in May and early June. It is counted among the river marsh types. and prefers shady spots in stagnant and slowly flowing water.

distribution

The species is mostly common in Central Europe. The distribution area extends from southern Europe to southern northern Europe and from there to western Siberia.

literature

  • 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 .

Individual evidence

  1. a b Philochthus biguttatus in Fauna Europaea. Retrieved March 14, 2011
  2. Red lists at BioNetworkX
  3. JCFabricius: Species insectorvm exhibentes eorvm differentias specificas, synonyma avctorvm, loca natalia, metamorphosin adiectis observationibvs, descriptionibvs, Bd.I Hamburg, Kiel 1781 first description p. 323, 68th genus, 83rd Art
  4. Sigmund Schenkling: Explanation of the scientific beetle names (species)
  5. Philochthus at Fauna Europaea. Retrieved March 20, 2013
  6. Species of the genus Philochthus at BioLib
  7. ^ Woog, Dieter. (2009) Investigation of the ground beetle fauna on the farm areas of an ecologically working farm in Northwest Mecklenburg Virgo, bulletin of the Entomological Association Mecklenburg 12th year, issue 1, pp. 47–53 as PDF
  8. Technical documents of the State Institute for the Environment, Measurements and Nature Conservation Baden-Württemberg: Soil as a habitat for soil organisms; Soil biological site classification (literature study) , online: PDF (22.3 MB)
  9. Polish koleopterologische page

Web links

Commons : Zweifleckiger Ahlenläufer  - Album with pictures, videos and audio files