Small brush foot
| Small brush foot | ||||||||||||
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Small brush foot ( Polyxenus lagurus ) |
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| Polyxenus lagurus | ||||||||||||
| ( Linnaeus , 1758) |
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The Small Pinselfüßer ( Polyxenus lagurus ), often just as the associated family and order Pinselfüßer called, is a holarctic widespread nature of the millipedes belonging Pinselfüßer . It is the only Central European brush-footed species and is very different from all other domestic double-footed species.
features
The body length of the tiny species is 2-3 mm, there are 13 pairs of legs on the 11 body rings. The antennas are eight-limbed and relatively short. In contrast to the body of all other domestic bipedes, Polyxenus lagurus has a soft-skinned body without calcium deposits, since the order Polyxenida has separated from the other bipedes in evolution, even before the reinforcement of the cuticle (outer skin) by calcium has developed. Likewise, they have no gonopods and no defensive glands, since these structures were only formed after the evolutionary separation of the pipods into the subclasses Penicillata and Chilognatha . The hair formations are a noticeable feature of the species. The hair stands in tufts like a paintbrush and is provided with barbs and branched and lobed structures. These hairs can break off easily and serve, among other things - especially in the case of the tail bristles - to ward off predators such as ants or spiders . The locomotion of the species is jerky, almost jumping. In addition, Polyxenus lagurus is an excellent climber and can also climb smooth, vertical surfaces such as glass.
Confusion is not possible in Central Europe with any other double pods. However, every now and then it is confused with the larvae of various bacon beetles , such as the cabbage beetle , carpet beetle or cabinet beetle , which, in contrast to the small brush- footed beetle , are considered pests in the house.
distribution
The species is distributed holarctic in Europe , Western Asia and North America . On mainland Europe it occurs from the Pyrenees to the Caucasus , but does not live on the Apennine peninsula . The southernmost occurrences are in Western Europe in southern France and in Eastern Europe in Greece . In the north, the species lives in the central areas of Sweden . In western Asia it is widespread as far as Israel . In addition to the mainland, the British Isles and Azores are settled. In North America, the species is known from the United States and Canada .
In Germany the species is very widespread and known from all federal states except Saarland . There is less evidence from northwest Lower Saxony , west Schleswig-Holstein , north from Saxony-Anhalt to southwest Mecklenburg-Western Pomerania and western Brandenburg and parts of southern Bavaria .
habitat
Due to their small size, the animals cannot dig and have evolved into tree dwellers. The species lives especially under the bark of many different tree species, up to a tree height of 20 m, also in moss cushions, ants and wasp nests. For trees, pine , other conifers, oaks or beeches with cracked bark are preferred. The dwarfism of the species suggests an ecological strategy, as it can find a hiding place almost anywhere where it is protected from bad weather. In addition to tree bark, stone walls are also settled.
The species prefers natural habitats and is rarely found synanthropic . Like the anthropods Proteroiulus fuscus and Nemasoma varicorne, it is one of the native forest species whose habitat is bark. The species is sensitive to high temperatures and drought, so cooler and more humid locations are preferred. When the humidity is high, the species can also cover its fluid needs from the water vapor contained in the air. The species is rarely found in houses because it does not get along well with the low humidity that prevails here.
Way of life
The animals are usually found in large groups of different ages under tree bark. The nutrition takes place mainly through green algae , which grow as growth on bark or stones also at lofty heights. But lichens and dead leaves are also eaten.
Reproduction and development
Reproduction also differs from that of other domestic double-pods, as there is no pairing. Since no running legs have been converted into organs of copulation, the males lack a tool for the direct transfer of the semen into the body of the female. So there is no mating in this species. Instead, the seeds pass via an indirect Spermatophoren transmission to females. With the help of various spinneret glands, the male creates a complex web of threads. First it creates a zigzag mesh of double threads with the spinning pens on the second pair of legs by pivoting the front body back and forth, on which it deposits two sperm droplets. Then it turns around, moves away from the zigzag mesh at a right angle and creates a thread line consisting of 4 threads. A secretion from the glandular pockets of the 8th and 9th pair of legs is used for this purpose. The street threads can reach five times the body length of the male (1.5 cm). They are thicker than the zigzag threads and resemble a pearl necklace due to additional, regularly spaced thickenings. These thickenings are interpreted as fragrance packages. As soon as a female encounters such a thread road, she begins to trill excitedly with the antennae, erect her sexual orifices (vulva) and follow the road. If it gets directly to the zigzag mesh, it immediately picks up the sperm droplets with the vulva at the base of the second pair of legs. However, if it runs in the wrong direction, it turns around at the end of the thread road, runs it back and now reaches the zigzag network with the sperm drop on the second attempt. If the female immediately encounters the zigzag pattern without having “experienced” the thread road beforehand, it ignores the sperm. This observation shows that the thread road not only shows the way, but also stimulates the ingestion of sperm.
The females lay eggs by laying the eggs in a circle like a string of pearls. Then the tail brush is pressed against the eggs again and again so that the prickly and barbed tail bristles attach to the eggs and thus prevent smaller predators, e.g. B. Repel predatory mites such as barbed wire. The hairy protective cover also has a ventilation function and ensures the most uniform possible small climatic conditions. Immediately after hatching, the young animals, equipped with three pairs of legs and a pair of four-limbed antennae, are able to run around and eat independently - a characteristic that distinguishes brush-feet and bores-pods from other domestic double-pods. After several moults, during which further body rings develop, the young animals develop into adults . The development from egg to adult animal takes about 6–8 months.
Danger
The species is considered endangered neither in Germany nor globally. In Germany it is described as being moderately frequent.
Taxonomy
The species was first described in 1758 by Carl von Linné under the name Scolopendra lagura . Other synonyms are Iulus lagurus ( Linnaeus , 1758), Julus lagurus Linnaeus , 1758, Pollyxenus lagurus ( Linnaeus , 1758), Iulus penicillatus DeGeer and Julus penicillatus DeGeer .
literature
- Harald Hauser & Karin Voigtländer: Doppelfüßer (Diplopoda) of Germany . DJN - German Youth Association for Nature Observation, 1st edition, Göttingen 2019, ISBN 978–3–923376–26 – X.
Web links
- The brush foot (Polyxenus lagurus). In: Institute for Pest Management. Retrieved June 15, 2021 .
- Polyxenus lagurus . In:Bodentier⁴ - Senckenberg, World of Biodiversity. Retrieved June 17, 2021.
Individual evidence
- ↑ Reip, HS, Spelda, J., Voigtländer, K., Decker, P. & N. Lindner (2016): Red list and list of total species of double-pods (Myriapoda: Diplopoda) of Germany. - In: BfN (ed): Red List of Endangered Animals, Plants and Fungi in Germany. Volume 4: Invertebrates (Part 2). - Conservation and biodiversity 70 (4): 301–324.
- ↑ Polyxenus lagurus (Linnaeus, 1758) in GBIF Secretariat (2021). GBIF backbone taxonomy. Checklist dataset [1] accessed via GBIF.org on June 15, 2021.