Four-spotted pine beetle

Four-spotted pine beetle
Four-spotted pine beetle under spruce bark
Systematics
Class : Insects (Insecta) Order : Beetle (Coleoptera) Family : Gloss beetle (Nitidulidae) Subfamily : Cryptarchinae Genre : Glischrochilus Type : Four-spotted pine beetle
Scientific name
Glischrochilus quadripunctatus
( Linnaeus , 1758)

The Vierfleckige Kiefernglanzkäfer ( Glischrochilus quadripunctatus ) is a beetle from the species-rich family of the gloss beetle . The genus Glischrochilus is represented in Europe with six species , all of which are black and have four yellowish to white spots.

The beetle is insignificant in terms of forestry and is not under nature protection.

Notes on names, synonyms and homonyms

The beetle was already described by Linnaeus in 1758 in the famous 10th edition of his Systema Naturae , which was defined as the starting point of the binomial nomenclature , as the 4th species of the genus Silpha under the name Silpha quadripunctata . The short description is: an elongated black silpha, with two rust-colored dots on the wing cover ( S. oblonga nigra, elytris punctis duobus ferrugineis ). Linnaeus quotes two earlier descriptions of the beetle. Among them is the description from 1746 by Linné in Fauna Svecica (1st edition): a black Dermestes with four red dots on the wings ( Dermestes niger, coleoptris punctis rubris quaternis ). This explains the species name quadripunctatus (from Latin "quattuor", in compounds "quádri-" for "four-" and "punctātus" for "dotted"), which names the four blemishes on the two wing covers. However, there are two other species native to Central Europe, Glischrochilus quadriguttatus and Glischrochilus quadrisignatus , as well as the synonym quadripustulatus whose name also refers to four blemishes on the elytra.

In the second edition of Fauna Svecica in 1761 Linnaeus changes the name and describes the species with the same text and with the same two earlier citations as the 446th species under the name Silpha quadripustulata . He also goes into the more precise form of the four blemishes. The need to rename quadripunctata to quadripustulata results from the fact that the name Silpha quadripunctata is used for the 453rd species, which describes the four-point carrion beetle and whose name also goes back to older descriptions. Some authors kept the older species name quadripunctatus , which was possible in combination with another generic name without risk of confusion, while others adopted the more recent name quadripustulatus .

In 1790, Olivier gave the genus Nitidula, introduced by Fabricius, number 9 in his multi-volume coloepterological work, and the eighth species of this genus was the four-spotted pine beetle under the name Nitidula quadripustulata , referring to the 446th species in Linné's 2nd edition of Fauna Svecica relates. Unfortunately, he gives the following, in his opinion new, species the name Nitidula quadripunctata . So there is the same species name quadripunctata , one quadripunctata by Linné and one by Olivier for two different but closely related beetle species . In order to avoid confusion, Bedel renamed the latter to Oliveri (Olivier's) in 1891 , and is now called hortensis after the older description by Geoffroy in Fourcroux 1785 .

In summary, it can be stated that the beetle, which is now called Glischrochilus quadripunctatus , bears the specific epithet quadripustulatus, a in most of the older German-language works on beetles , while the species called quadripunctatus, a is now listed as Glischrochilus hortensis .

The genus name Ips is now reserved for a genus of bark beetles Ips , which De Geer described in 1775. Regardless of this, Fabricius named his 19th genus Ips in 1776 and marked it as new with an * as was customary at the time. Fabricius thus characterizes a group of gloss beetles , which also includes the four-spotted pine beetle. The name Ips , which is derived from the ancient Greek word ips ιπς for a worm that eats horn or wood, was used in different ways by different authors in the following years, both in the male and in the female sex. The description of the larva of the four-spotted pine beetle by Perris in 1877 was under the name Ips quadripunctata .

In 1873 Reitter separated the genus Ips described by Fabricius into three subgenus and placed the four-spotted pine beetle in the subgenus Glischrochilus with the name Glischrochilus quadripustulatus . The subgenus later becomes the genus. Of the Central European species now belonging to the genus Glischrochilus , Reitter later placed all except quadripustulatus in the genus Librodor established by him in 1884 . However, this division is no longer used today.

Reitter takes the generic name Glischrochilus from the Englishman Murray , whose unfinished work on gloss beetles he finishes. Glischrochilus is from old Gr. γλίσχρος “glis-chrós” for “sticky” and χῦλός “chilós” for “juice” and indicates the use of flowing tree sap as a source of food.

Since the word dot is (also) used in insects for small punctures in the skeleton, and the word blemish for spot has become uncommon, the species is called Vierfleckig in German . The part of the name Glanzkäfer alludes to family affiliation, the part of the name pine to its occurrence under the bark of pine trees. However, this is misleading as it is also common under spruce and fir bark.

Characteristics of the beetle

Fig. 1: different views
Fig. 2: Prosternal process (head left)	Fig. 3: Lower lip (left) and lower jaw with feeler

The black beetle with the four orange-yellow spots measures about half a centimeter, but can be up to eight millimeters long. On the head, pronotum and elytra, it is equally moderately fine and fairly widely dotted . It can be best distinguished from the similar Central European species by the proportions of the pronotum and the shape of the prosternal process (Fig. 2). This extension of the front chest, which runs backwards between the front hips, does not end rounded, but almost trimmed with an almost straight line of hair, while this line of hair is strongly arched or angled in the other species. In addition, the body is less rounded than the other species. For this reason, Reitter separates the other species as the Librodor genus from the Glischrochilus genus .

The triangular to semicircular head is significantly larger in the male than in the female. The mouthparts point forward. The bilobed upper lip is fused with the head shield . The lower lip with the three-part lip probe and the lower jaw with the four-part jaw probe are shown in Fig. 3. The antennae arise in front of the lateral flat eyes and can partially be inserted into a antenna groove that runs downwards in front of the eyes and then backwards (recognizable in side view and on the underside in Fig. 1 by the darker color). The antennae are eleven-limbed and end in an oval, three-limbed, flattened club. The club and the basal phalanx are black, the whiplash pods are dark red-brown. On the forehead there is a shallow transverse impression and usually a shallow central dimple.

The pronotum is only slightly wider than the head, in the female it is slightly narrower in front than the elytra, in the male it reaches the width of the elytra. The sides are set off broadly and slightly curved upwards, the side edge throat narrows in front of the middle. The sides of the pronotum are roughly parallel, the pronotum narrows slightly towards the back. In front of the sharply right-angled posterior corners, the pronotum is slightly drawn in and is narrower at the base than the elytra. The latter does not apply to the other Central European species.

The glossy elytra are over three times as long as they are wide and two and a half times as long as the pronotum. Behind the base, next to the shoulder bulge, you have a large blemish that spares the shoulder itself, and a large transverse blemish close to the center. At the rear, the elytra in the male are truncated transversely, while in the female they are truncated very diagonally with an extended seam angle. The sides are more parallel than in the other species.

The legs are short and strong. The yellowish brown tarsi are all five-limbed, but appear four-limbed because the fourth limb is very small.

larva

Details of the larva according to Perris
Fig. 4: Sensor	Fig. 5: 9th abdominal segment from above, colored on the right : pseudocercia green, bristled red tooth	Fig. 6: Pseudo Cercié (green) of laterally inside red: beborstetes Zähn- chen

The larva was first described by Perris in 1877, the description was made more precise in 1917 by Saalas, and in 1923 by Verhoeff, through more precise drawings and additional consideration of the tracheal system, it was substantially expanded.

The yellowish white larva becomes up to eleven millimeters long in the last stage. The body is flat and almost the same width almost everywhere, only it narrows slightly at both ends. Each of the middle body segments is more than twice as wide as it is long. The body is leathery and very fine and briefly tomented so that it appears frosted with gold shimmer. Individual longer tactile bristles are only sparsely found.

The flat head is much wider than it is long. It is smooth, bare, shiny, and rust-red due to the chitinization. On the forehead he has two diagonally running furrows, which are connected at the back by a transverse impression. In the middle it shows a clear dimple. There are four individual eyes on each side . The feelers (Fig. 4) are four-part. The base link is short, thick, and retractable. The two following links are about the same length, longer and thinner than the base link. The end link is the same length as the previous link, but much thinner. At its tip there is a long hair and some very short hair. Next to the base of the distal phalanx rises an appendix that is about half the length of the distal phalanx.
The upper lip is much wider than it is long, not pinched on the sides, indented in the middle and ciliate extremely short on the front edge. The red-brown upper jaw ends with a strong end tooth, in front of which there are three front teeth on the inside. The grinding plates carry around twenty rows of files that are curved in parallel and become increasingly finer towards the bottom. Between the grinding plate and the tip there are 12 to 13 combs arranged one behind the other, the fine structure of which changes gradually. The ark of the lower jaw is short and rounded and covered with very fine and short golden shimmering hairs. Inwardly, it has two short cones opposite the root of the jaw palpable. In addition to the jaw probe, the lower jaw is thickened like a knot. The four-part jaw probes are short and protrude only a little over the lower jaw. Your limbs are about the same length and increasingly slimmer. The base segment is incomplete, the terminal segment very finely haired. The chin is remarkably small and clearly set off from the adjacent parts. The so-called syncoxit of the labiopods, which divides into three branches at the front, attaches to the front edge of the chin. In the side branches sit the undivided cone-shaped lip probes, in front of the middle the small heart-shaped lower lip.

The prothorax is one and a half times as long as the mesothorax. Except for the center line, the front and rear edges, it is reddish-yellow, with faint impressions and two to three short hairs on each side. Meso- and metathorax are of the same length and yellowish white. They each have a hair on either side.

The hips of the three pairs of legs are set wide apart. The legs only slightly protrude from the side of the body.

The first abdominal segment is slightly larger than the metathorax and shorter than the following seven. All eight are bulging on the sides and have two very fine hairs there. They have eight hairs on the top and four or six on the bottom in a horizontal row. The ninth abdomen segment is already somewhat narrower in front than the eighth, but narrows sharply towards the rear and ends in two hook-shaped appendages curved upwards. Inside the projections under the tip are reinforced with a small black tooth with a long bristle (Fig. 6). When viewed from above (Fig. 5), the ninth segment appears semicircular, only the appendages protrude backwards, separated by a semicircular bay, the bristled tooth appears as a little cusp protruding into the bay. In front of the hook processes there are two horny rust-red cusps with two or three hairs at the base. Other hairs are sparsely distributed around the hook processes and one hair is found at the tip of the tooth on the inside of the hook process. The last and tenth abdomen segments, the anal segment, will be visible in the center of the underside of the ninth segment. It forms a diagonally drawn ring and encloses two finely haired anal valves.

The pair of spiracles of the first abdominal segment lies laterally near the front edge and is slightly larger. In the following segments, the spiracles are shifted a little further back and are located on the eighth abdominal segment near the rear edge.

biology

The larvae develop mainly in coniferous trees (pines, spruces, firs), but also in deciduous trees ( beech , alder , robinia ). The beetles can be found in coniferous and mixed forests and pine heather , and they have been seen licking up sap from robinia and birch trees . The adults are particularly strongly attracted by freshly felled and stacked spruce wood and can be found there under still damp chips or cut surfaces. They colonize ailing and dead trees. The larvae can be found in the tunnels of Tomicus , Ips and other bark beetle species in damp to wet surroundings.

On the spruce, the beetle is found on standing and lying trunks, but most often on stumps. The species lives under the bark in places where the underside of the bark is covered with slimy sap. The larvae are often found gregarious. In the experiment it is sufficient for the beetle to develop if the larvae are fed this juice. The larvae also fall on live prey and suck them up, but they mainly feed on sludge mixed with tree sap. Experiments with hormone traps suggest that they play a subordinate role as antagonists of bark beetles, at least in beech forests.

As experiments show, the larvae are quite insensitive to flooding. They can also survive underwater for a long time (two to three days). Larvae move much more agile on moist ground than on dry ground. For pupation, the larvae dig into the ground and make a pupa cradle. The dolls are provided with movable spiky appendages that prevent them from lying completely in the water.

Usually the eggs are laid in spring, the new generation appears in August, overwinters and lays the eggs in the coming spring. However, if the eggs are laid late, the pupae can also overwinter and the adults do not hatch until next spring.

distribution

The species is widespread in almost all of Europe, it is only absent on Gibraltar San Marino , the city-states Monaco and Vatican City and almost all islands ( Azores , Balearic Islands , Canaries , Madeira , Malta , Crete , Cyclades , Cyprus , the Dodecanese archipelago , the North Aegean) Islands , the channel Islands , Iceland , the Faroe Islands, Franz Josef land , Novaya Zemlya , the Selvagens and the archipelago of Svalbard ). The occurrence has been proven in Sicily , but doubtful in Sardinia . The species is becoming rarer in Northern Europe. To the south it reaches the distribution area North Africa, to the east the beetle can be found in the Middle East and into the Eastern Palaearctic.

literature

• Heinz joy, Karl Wilhelm Harde, Gustav Adolf Lohse (ed.): The beetles of Central Europe . tape 7 . Clavicornia. Spektrum Akademischer Verlag, Munich 1967, ISBN 3-8274-0681-1 , p. 74 .
• Klaus Koch : The Beetles of Central Europe Ecology . 1st edition. tape 2 . Goecke & Evers, Krefeld 1989, ISBN 3-87263-040-7 , pp. 164 .
• Edmund Reitter : Fauna Germanica, the beetles of the German Empire III. Volume, KGLutz 'Verlag, Stuttgart 1911 p. 38 as Glischrochilus quadripustulatus

Individual evidence

1. ↑ ^{a b} Glischrochilus quadripunctatus in Fauna Europaea. Retrieved October 22, 2015
2. ↑ Glischrochilus at Fauna Europaea. Retrieved October 9, 2015
3. ↑ Carolus Linnaeus: Systema Naturae .... 1st volume, 10th edition, Stockholm 1758 p. 363: 359 No. 4 4-punctata
4. ↑ Carolus Linnaeus: Fauna Svecica .... Stockholm 1746 p. 136 No. 364 Dermestes ...
5. ↑ ^{a b} Sigmund Schenkling: Explanation of the scientific beetle names (species)
6. ↑ Carolus Linnaeus: Fauna Svecica .... Editio altera augmenta (2nd enlarged edition), Stockholm 1761 p. 197: 148 No. 446 Silpha quadripustulata , No. 453 Four-point carrion beetle
7. ↑ M. Olivier: Entomologie ou Histoire Naturelle des Insectes Coleoptères Tome II Paris 1790 as the 9th species of the 12th genus Nitidula quadripustulata and as the 10th species of the 12th genus Nitidula quadripunctata
8. ↑ Glischrochilus hortensis in Fauna Europaea. Retrieved October 29, 2015
9. ^ Heyden, Reitter, Weise: Catalogus Coleopterorum Europae, Caucasi et Armeniae rossicae 2nd edition Berlin, Paskau, Caen 1906, p. 325
10. ↑ ^{a b c} Ludwig Ganglbauer : The Beetles of Central Europe III. Volume, 1st half 2nd part, Vienna 1899, p. 554 as Glischrochilus quadripustulatus with a detailed list of the names of quadripustulatus and quadripunctatus by different authors
11. ↑ Ips at Fauna Europaea. Retrieved October 25, 2015
12. ^ Johann Chr. Fabricius: Genera Insectorum Kiel 1776: p. 23
13. ↑ ^{a b c d} Édouard Perris: Larves de Coléoptères Paris 1877, p. 43 as Ips quadripunctata and illustrations, panel 1, Fig. 29-32
14. ↑ ^{a b} Edmund Reitter : Systematic division of the nitidularia in negotiations of the natural research association Brünn , XII. Volume, 1st issue, 1873 Glischrochilus p. 162, reference to Murray in the introduction
15. ↑ ^{a b c d} Edmund Reitter : Fauna Germanica, the beetles of the German Empire III. Volume, KGLutz 'Verlag, Stuttgart 1911, synonyms p. 38, illustrations panel 85, figure 15, a, b
16. ↑ Edmund Reitter : Die Nitiduliden Japans in Wiener Entomologische Zeitung Vol. 3 Vienna 1884 p. 257, description p. 270
17. ↑ Sigmund Schenkling: Explanation of the scientific beetle names (genus)
18. ↑ ^{a b c} Uunio Saalas: The Spruce Beetles of Finland 1. Volume Helsinki 1917 Description and ill. To panel VIII Fig 104-107
19. ↑ ^{a b c} K.W. Verhoeff : Contributions to the knowledge of the Coleopterenlarva in Archiv der Naturgeschichte 1923 Volume 89, Issue 1 Description of the larva and description of the drawings and drawings on panel II, Fig. 22 - 24
20. ↑ Åke Lindelöw, Birger Risberg, Kristina Sjödin: Attraction during flight of scolytids and other bark- and wood-dwelling beetles to volatiles from fresh and stored spruce wood Canadian Journal of Forest Research Volume 22, Number 2, February 1992
21. ↑ ^{a b} Ralf Petercord: Bark beetles and their antagonists in Rhineland-Palatinate beech forests in messages from the German Society of General Applied Entomology 16. Giessen 2008 as PDF
22. ↑ Distribution in Finland , on world map in Norway Occurrence in Europe by FE  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.  

Web links

Commons : Vierfleckiger Kieferglanzkäfer ( Glischrochilus quadripunctatus )  - album with pictures, videos and audio files