Springtails

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Springtails
Springtail (Isotoma anglicana), enlarged about 40 times. The ventral tube (between the legs) and furca are visible under the abdomen

Springtail ( Isotoma anglicana ), enlarged about 40 times. The ventral tube (between the legs) and furca are visible under the abdomen

Systematics
Over trunk : Molting animals (Ecdysozoa)
Over trunk : Molting animals (Ecdysozoa)
Trunk : Arthropod (arthropoda)
Superclass : Six-footed (Hexapoda)
Class : Sackkiefler (Entognatha)
Order : Springtails
Scientific name
Collembola
Lubbock , 1870
Submissions
(Euedaphic) springtails living in the pores of the soil are slightly pigmented or completely white. Protaphorura armata is often found in human-influenced soils
Springtails ( Anurida maritima , Neanuridae) on the water surface near the coast

The springtails (Collembola) are one of the Sackkieflern (Entognatha) belonging order of the hexapods (Hexapoda). They reach a body length of 0.1 mm to 17 mm and are found mainly in layers of humus that are not too dry, in the soil pores up to a depth of a few meters and on rotting plant material. They also colonize such diverse habitats as rainforests, coastal areas, sand dunes, deserts or areas of snow in the high mountains. Around 9,000 species are known worldwide in 2020.

features

Springtails show the three-part division of the body, typical of the Hexapoda, into the head, the thorax (chest) and the abdomen (abdomen). Insects normally have eleven abdominal segments, whereas the Collembola only have six, which are already created during embryonic development. Most species are between 1 and 5 mm long. Above-ground ( epedaphic ) species tend to be darkly pigmented, sometimes with species-specific coloring patterns, thick hairs and large body appendages. Euedaphic species living predominantly or exclusively in the soil are slightly colored to completely white in the pore structure of the soil as an adaptation to their way of life, of compact physique, with short antennae, partially or completely reduced ankle fork and reduced number of eyes. The body is only slightly sclerotized in all species , its surface ( epicuticle ) is covered with numerous microtubercles , which on average measure about 0.3 micrometers and are water-repellent. Only a few groups of the ball jumpers have a tracheal system; most Collembola breathe exclusively through their thin-walled cuticula.

Orchesella flavescens belongs to the Entomobryidae family, in which species-specific coloring patterns often occur

Collembola are counted as Entognatha because their mouthparts are in an oral pocket and outside are not visible.Most of these wingless animals are characterized by their ankle fork (furca, sometimes also furcula), which is located on the fourth abdominal segment. It consists of three parts: the basal manubrium, the long paired dentes and, at the end of each, a short hook structure, the mucro. There are cutinized “teeth” between the manubrium and dentes , which fit exactly into the hooks of the retinaculum, a structure on the third abdominal segment, and thus hold the furca ventrally on the abdomen under tension. If the animal is irritated, it loosens this connection, the mucrones drill into the ground and the collembole performs an undirected jump out of the danger zone. The jump distance is a multiple of his own body length. In many species living in the ground, the furca has regressed; some instead give up defense secretions in case of danger, which act as a deterrent to their predators.

The iridescent scales that often appear on the body surface of the Entomobryomorpha serve not only to protect against radiation but also to protect against predators by making it difficult for them to hold onto their prey

Common to all species is the ventral tube (collophor) located behind the legs, which is located on the first abdominal segment and probably plays an important role in the water and electrolyte balance. With the help of the ventral tube, springtails can also hold onto smooth surfaces and move around. The English natural scientist John Lubbock derived the scientific name Collembola from this structure , after the Greek kolla “glue” and embolon “wedge, cone”.

The complex eyes of springtails consist of a maximum of eight ommatidia , which are often reduced or completely regressed. In most species, the postantennal organ is found between the antenna base and the ommen field, a sensory organ in a recess in the skin that serves for chemoreception and represents the remainder of a receding second antenna. Springtails usually reach an age between six and twelve months, the age record in the laboratory is five and a half years. During this period they molt about four to over fifty times. Depending on age and fitness, a female lays several hundred eggs, singly or in several clumps of clutch. The young resemble the adult; they differ from these in size, lower pigmentation, proportions of the body segments and the lack of genital opening and individual body features (e.g. sensillae). A reliable determination is therefore only possible in the presence of fully grown specimens. The young animals reach sexual maturity after about five to eight moults.

Habitat, distribution and abundance

Springtails live on the ground, in the leaf litter and in the pore structure of the ground to a depth of about 20 centimeters, but also on tree bark, in dead wood, on the surface of the water, on the coast of the sea, on glaciers and in nests of ants and termites . They prefer high humidity, some species are attracted by carbon dioxide.

Due to their water-repellent cuticula , they can withstand flooding of the soil pore system, for example in floodplain soils , in an air bubble or maneuver on the water surface. Some species such as the black diver graze there specifically on algae, bacteria and protozoa. Springtails can survive floating on the open sea for up to 14 days, covering several hundred kilometers. As a result, they gain importance as the first colonizers of new, sterile areas (see also Surtsey ). Species such as snow and glacier fleas live in the system of gaps in scree, in moss cushions and crevices in the high mountains and feed on the conifer pollen and fungal spores that are blown onto the ice. These species are still active at temperatures around -5 ° C. Arctic Collembola can survive frozen at −20 ° C for at least four years.

Several species are known to be able to absorb and immobilize heavy metals from the soil . Among other things, these abilities make Collembola important first-time and resettlers of disturbed or contaminated soils, such as flooded floodplain soils or spoil heaps.

The oldest known fossil finds of Collembola are around 400 million years old. Springtails are among the oldest land-living animals at all, which explains their worldwide distribution in almost all terrestrial habitats. They prefer cool, humid and rather low-light ambient conditions.

Dicyrtomina ornata is one of the species that actively move on surfaces of litter and vegetation in daylight

Springtails are considered to be the most common hexapods; In one square meter of forest floor in temperate latitudes, between 10,000 and over 100,000 individuals live in the top 30 centimeters. After the mites , they are the most individual group of animals in the mesofauna in the soil. Their frequency is based on factors such as light conditions, moisture, humus shape, soil pH and nutrient availability. Accordingly, they are not evenly distributed, but rather concentrated in “hotspot” patterns wherever they find optimal living conditions. Here they can build up mass populations at short notice and show conspicuous swarming behavior on warm winter days or in early spring.

Swarming springtails in the compost

food

Most species of springtails are polyphagous detritus eaters . In addition to these 'omnivores', there are also specialists who primarily eat algae , fungi , carrion, excrement or pollen or graze on soil microorganisms. The predators of the Collembola include, in particular, mites, spiders, harvestmen, pseudoscorpions, double tails, centipedes, ground beetles, raven beetles, two-winged beetles, ants and bugs.

Ecological and economic importance

The Lucerne Flea ( Sminthurus viridis ) belongs to the ball divers

By breaking down their food, they play a key role in the formation of humus . They remove organic residues and thus promote soil fertility and thus the growth of plants. Since they turn the remains of plants into natural fertilizers, they are of considerable benefit to agriculture .

Only a few species, such as B. the lucerne flea ( Sminthurus viridis ) are considered pests for agricultural systems. Springtails can occasionally be harmful to monocultures in the open air as well as to house plants if their actual food source, vegetable detritus , is running out and they eat the living fine roots. On the other hand, through targeted grazing of fungal mycelia, they reduce the risk of fungal attack in seeds and seedlings and thus contribute to plant protection in agro-ecosystems. Some springtail species are sensitive to anthropogenic disturbances in the soil and are therefore used in the laboratory in standard tests to detect soil contamination . In particular, the flowerpot springtail Folsomia candida (Isotomidae), which is easy to keep in the laboratory, provides information on the presence of interfering substances and harmful substances by changing its feeding and reproductive behavior or by avoiding experiments.
Humans have given only a few springtail species a common name . In addition to some agricultural pests (e.g. alfalfa flea), these include above all species with conspicuous mass occurrences at certain times of the year ( snow flea ) or in certain habitats ( glacier flea , black diver , flowerpot springtail).

Systematics

Isotomurus maculatus (Isotomidae) is a common species in anthropogenically influenced habitats

The springtails (Collembola) were traditionally counted among the insects and placed here with other wingless taxa as "urine insects" ( Apterygota ) at the base of the insecta. Meanwhile, the Apterygota are seen as paraphyletic and the springtails as a separate order within the hexapods (Hexapoda). Since they share several common characteristics, the leg taster (Protura) are considered to be their sister group. After one of these characteristics, the absence of abdominal attachments , both groups together are referred to as Ellipura designated (Greek έλλειψις elleipsis "absence" and ουρά Oura "tail"). This classification goes back to Willi Hennig, as well as the assignment of the double tails as sister group of the Ellipura. Protura, Collembola and Diplura are summarized as orders of the Entognatha , because only in these three groups the mouthparts are in the head capsule instead of outside as in most insects. New fossil discoveries and molecular genetic studies call this traditional view into question. On the basis of mitochondrial gene sequences, a closer relationship between the Collembola and the gill pods or the jaw pods is postulated. According to these models, the segmented physique of the Hexapoda would have developed independently of one another several times. Investigations of ribosomal protein sequences , however, support a closer relationship between the Collembola and the winged insects , followed by the gill pods and the higher crustaceans as the closest related taxa, which would be more in line with the morphologically based family trees. A more recent study on the basis of ribosomal sequences, an increased number of examined taxa and an optimized feature weighting partially supports the position of the Collembola as a monophyletic taxon within the Hexapoda and places the Protura and Diplura as a common sister group ("Nonoculata") alongside them, but without to be able to confirm this division in all investigated calculation models. Until further RNA-independent characteristics are included in the pedigree analysis, the actual position of the Collembola within the arthropod remains unclear.

Allacma fusca (Sminthuridae) on rotting wood (video, 1m 28s)

Originally, the Collembola was divided into the elongated Arthropleona and the more rounded Symphypleona (spherical diver) with their typical fused abdominal segments. The newer systematics replaces the subclass Arthropleona with Poduromorpha and Entomobryomorpha, which are placed as separate orders next to the Neelipleona and Symphypleona. Other systematists see the Neelipleona as belonging to the Sminthuroidea. The proportions of the thoracic and abdominal segments are still used to subdivide the large groups: in the Entomobryomorpha the tergite of the first thoracic segment is shortened, largely disappears between the head and the second thoracic segment and does not have bristle hairs (Chaetae or Setae), which is Poduromorpha it develops normally and bears at least a number of chaetae. Within the Entomobryomorpha, the fourth abdominal tergite of the Entomobryidae is significantly longer than the third, while in Isotomidae both are about the same length. In the Symphypleona, the spherical abdomen structure is mainly formed by the abdominal segments, in the Neelipleona (or Neelida) mainly by the thorax segments.

The flowerpot springtail Folsomia candida can often be found in potting soil or compost. As a frugal, easy to keep species with rapid reproduction ( parthenogenetic ), this species is also a standard test organism in laboratory tests, for example on ecotoxicology

The number of collembola species actually present on the planet has been estimated at 50,000, around 9,000 species have been described worldwide to date. Information on the number of species described fluctuates greatly, which is not least due to the fact that many species and groups of species are very difficult to identify and distinguish. Complex genital structures, as used in many other Hexapoda for appraisal, are not present in the Collembola. In the case of species of some Collembol genera (e.g. Isotomurus , Orchesella ), the color pattern can be used for species identification, while the corresponding patterns vary greatly even in closely related genera. In the palearctic widespread families of the Hypogastruridae and Isotomidae, ecomorphoses are observed, i. H. Unfavorable environmental conditions, especially drought and heat, can influence the morphological design of the body appendages, the bristling of individual body segments and the mouthparts. In isotomids that inhabit cold climates, such ecomorphoses occur regularly as cyclomorphoses, winter and summer forms differ in shape and form, v. a. the furca and the legs. Since the expression and proportions of such features are often used to diagnose species, the number of species that actually exist remains subject to uncertainties. For example, the species Tullbergia (Mesaphorura) krausbaueri (Börner, 1901) was regarded as a well-demarcated species as late as 1960, after which it was recognized as a group of difficult-to-distinguish varieties or cryptic species and initially referred to as the " Tullbergia krausbaueri group". More precise methodological approaches now divide this group into eight genera and 43 valid species in the Palearctic alone. The similarly problematic Protaphorura armata complex includes, depending on the author, one, thirteen or up to 44 species along with various subspecies.

The white water ball divers ( Sminthurides aquaticus ) can hardly be seen with the naked eye; Similar to the larger black diver , they can be found on the surface of still waters

As before, both new species are described and, for those already described, the species status is determined more precisely by applying more precise methods in order to identify valid biological species from the previously imprecisely defined transition area between species complex, species, color morph, subspecies and variety. The introduction of new taxonomic features facilitates the necessary distinction between intra- and inter-species variability. While color patterns are becoming less important due to their high variability, chaetotaxia , i.e. the presence or absence of certain bristles in defined positions of a body segment, is being used more and more to successfully differentiate between species. The chaetotaxia of the first molting stages also serves to clarify the relationships of the higher collembolic taxa. The fine structure of the mouthparts also provides important defining characteristics, but requires careful preparation. Molecular biological methods have been used successfully to dissolve cryptic species complexes since the 1970s, but they also led to an ongoing dispute about the actual position of the Collembola inside or outside the Hexapoda.

Types (selection)

Trivia

The dark brown spherical diver ( Allacma fusca ) was named “Insect of the Year 2016” in Germany , Austria and Switzerland . Strictly speaking, the dark brown puffer is not an insect.

See also

swell

Individual evidence

  1. ↑ McMeechan, FK; Manica, A .; Foster, ovg.A. (2000). Rhythms of activity and foraging in the intertidal insect Anurida maritima : Coping with the tide. Journal of the Marine Biological Association of the United Kingdom, 80, 189-190.
  2. ↑ Suhardjono, YR; Greenslade, P. (1994). Folsomides arnoldi n.sp. (Isotomidae): A new Collembolan abundant in arid Australia, with a redescription of Folsomides denisi (Womersley). Proceedings of the Linnean Society of New South Wales, 114, 21-27.
  3. ↑ Yosii, R. (1966). Snow Collembola of the Siachen Glacier in Karakoram. Results of the Kyoto University Scientific Expedition to the Karakoram and Hindukush, 8, 407-410.
  4. ↑ Wolfgang Hemmer: Onychiurus (Protaphorura) kolenatii n.sp. (Collembola), an optionally red-colored onychurid species from high alpine snowfields in the Eastern Alps. In: Vorarlberger Naturschau. 8, Dornbirn 2000, pp. 145–152 ( PDF on ZOBODAT ).
  5. ↑ Dettner, K., Scheuerlein, A., Fabian, P., Schulz, S. & Francke, W. (1996). Chemical defense of giant springtail Tetrodontophora bielanensis (Waga) (Insecta: Collembola). Journal of Chemical Ecology, 22, 1051-1074.
  6. ↑ Messner, C., Walther, J., Dettner, K. & Schulz, S. (2000). Chemical deterrents in podurid Collembola. Pedobiologia, 44, 210-220.
  7. ^ Lubbock, J. (1873). Monograph of the Collembola and Thysanura. London: The Ray Society.
  8. ↑ Lawrence, PN (1999). From whence and whither the Collembola? Crustaceana, 72, 1110-1122.
  9. ↑ Barra, JA (1976). Le developpement postembryonnaire de Pseudosinella decipiens et P. impediens sous certaines conditions expérimentales. Revue d'Ecologie et de Biologie du Sol, 13: 385–397
  10. ^ Mari Mutt, JAM & Soto-Adames, FN (1987). Moulting, fecundity, and longevity in Willowsia jacobsoni (Collembola: Entomobryidae). Caribbean Journal od Science, 23: 298-304
  11. ^ Christiansen, KA in Dindal (1990). Insecta: Collembola. Soil biology guide. John Wiley & Sons, New York etc .: 965-995
  12. ^ Waldorf, ES (1971). The reproductive biology of Sinella curviseta (Collembola: Entomobryidae) in laboratory culture. Revue d'Ecologie et de Biologie du Sol, 8: 451–463
  13. ↑ Sharma, GD (1967). Bionomics of Tomocerus vulgaris Tullberg (Collembola, Entomobryidae). Proceedings of the Royal Entomological Society of London, 42A: 30-34
  14. ^ Dunger, W. & Fiedler, HJ (1989). Methods of soil biology. Jena: Gustav Fischer Verlag.
  15. ↑ Coulson, SJ, Hodkinson, ID, Webb, NR & Harrison, JA (2002). Survival of terrestrial soil-dwelling arthropods on and in seawater: implications for trans-oceanic dispersal. Functional Ecology, 16 (3): 353-356.
  16. ↑ Coulson, SJ & Birkemoe, T. (2000). Long-term cold tolerance in Arctic invertebrates: recovery after 4 years at below -20 ° C. Canadian Journal of Zoology, 78 (11): 2055-2058.
  17. ↑ Russell, D., Hauth, A. & Fox, O. (2004). Community dynamics of soil Collembola in floodplains of the Upper Rhine Valley. Pedobiologia, 48 (5-6): 527-536.
  18. ↑ Rusek, J. (2004). Collembola succession on deposits from a chemical factory. Pedobiologia, 48 (5-6): 519-524.
  19. ↑ Petersen; H. & Luxton; M. (1982). A comparative analysis of soil fauna populations and their role in decomposition processes. Oikos 39: 287-388.
  20. ↑ ponge; Jean-François; Arpin; Pierre; Sondag; Francis & Delecour; Ferdinand (1997). Soil fauna and site assessment in beech stands of the Belgian Ardennes. Canadian Journal of Forest Research. 27: 2053-2064.
  21. ^ Zettel, J. & Zettel, U. (2008). Some like it cold: the biology of the “snow flea ” Ceratophysella sigillata (Uzel, 1891), a winter-active springtail species (Collembola: Hypogastruridae). Announcements from the Natural Research Society in Bern, 65, 79–110.
  22. ^ Thibaud, JM (1970). Biologie et écologie des Collemboles Hypogastruridae édaphiques et cavernicoles. Mémoires du Muséum National d'Histoire Naturelle, NS, Série A, LXI, 83-201.
  23. ^ Bishop, AL, Harris, AM & McKenzie, HJ (2001). Distribution and ecology of the lucerne flea, Sminthurus viridis (L.) (Collembola: Sminthuridae), in irrigated lucerne in the Hunter dairying region of New South Wales. Australian Journal of Entomology, 40, 49-55.
  24. ↑ Sabatini, MA & Innocenti, G. (2001). Effects of Collembola on plant-pathogenic fungus interactions in simple experimental systems. Biology and Fertility of Soils, 33, 62-66.
  25. ^ Fountain, MT & Hopkin, SP (2005). Folsomia candida (Collembola): A "Standard" Soil Arthropod. Annual Review of Entomology, 50, 201-222.
  26. ↑ Hennig, W. (1969). The tribal history of the insects. Waldemar Kramer, Frankfurt am Main.
  27. ^ A b Nardi, F. Spinsanti, G., Boore, JL, Carapelli, A., Dallai, R., Frati, F. (2003). Hexapod Origins: Monophyletic or Paraphyletic? Science, 299 (5614), 1887-1889.
  28. ^ Cook, CE, Yue, Q., Akam, M. (2005). Mitochondrial genomes suggest that hexapods and crustaceans are mutually paraphyletic. Proceedings of the royal Society of London Series B, 272, 1295-1304
  29. ↑ Timmermans, MJTN, Roelofs, D., Mariën, J., van Straalen, NM (2008). Revealing pancrustacean relationships: Phylogenetic analysis of ribosomal protein genes places Collembola (springtails) in a monophyletic Hexapoda and reinforces the discrepancy between mitochondrial and nuclear DNA markers. BMC Evolutionary Biology, 8 (83).
  30. ↑ von Reumont, BM, Meusemann, K., Szucsich, NU, Dell'Ampio, E., Gowri-Shankar, V., Bartel, D., Simon, S., Letsch, HO, Stocsits, RR, Luan, YX , Wägele, JW, Pass, G., Hadrys, H. & Misof, B. (2009). Can comprehensive background knowledge be incorporated into substitution models to improve phylogenetic analyzes? A case study on major arthropod relationships. BMC Evolutionary Biology, 9 (119).
  31. ↑ Börner, C. (1901). To the knowledge of the apterygote fauna of Bremen and the neighboring districts. Treatises of the Natural Science Association in Bremen, 17, 1–141.
  32. ↑ a b Deharveng, L. (2004). Recent advances in Collembola systematics. Pedobiologia, 48, 415-433.
  33. ↑ Hopkin, SP (1997). Biology of the Springtails (Insecta: Collembola). Oxford: Oxford University Press.
  34. ↑ http://www.collembola.org/ , Version 31.xii. 2019, accessed on 25.i.2020.
  35. ↑ Cassagnau, P. (1971). Les différents types d'ecomorphose chez les Collemboles Isotomidae. Revue d'Ecologie et de Biologie du Sol, 8, 55–57.
  36. ^ Bourgeois, A. (1973). Polymorphisme et épitoquie chez Ceratophysella tuberculata (Collembole, Hypogastruridae), Revue d'Ecologie et de Biologie du Sol, 10, 589-601.
  37. ↑ Rusek, J. (1971). On the taxonomy of the Tullbergia ( Mesaphorura ) krausbaueri (Börner) and their relatives (Collembola). Acta Entomologica Bohemoslovaca, 68, 188-206.
  38. ↑ Dunger, W. (1991). Ecological testing of morphological species of the "Tullbergia krausbaueri group" (Insecta: Collembola). Messages from the Museum für Naturkunde in Berlin, 67 (1): 131–140.
  39. ↑ Bödvarsson, H. (1970). Studies of Onychiurus armatus (Tullberg) and Folsomia quadrioculata (Tullberg) (Collembola). Opuscula Entomologica, Supplementum, 182 pp.
  40. ↑ Pomorski, R. (1990). Morphological-systematic studies on the variability of pseudocelli and some morphological characters in Onychiurus of the " armatus -group" (Collembola, Onychiuridae) Part II. On synonyms within the armatus-group , with special reference to diagnostic characters. Annales Zoologici, 43, 535-575.
  41. ^ Gisin, H. (1960). European collembola fauna. Geneva, Musée D'Histoire Naturelle, 311 pp.
  42. ↑ Delsuc, F., Phillips, MJ, Penny, D. (2003). Comment on "Hexapod Origins: Monophyletic or Paraphyletic?" Science, 301 (5639), 1482.

literature

  • Dunger, W. (1983). Animals in the ground. Westarp Sciences, 4th ed. 2008. ISBN 3-89432-424-4
  • Dunger, W. (1996). Order Collembola, springtails. In: Westheide, W., Rieger, R., Special Zoology. Part 1. Protozoa and invertebrates (pp. 71–86). Stuttgart u. a .: Gustav Fischer Verlag. ISBN 3-437-20515-3
  • Hopkin, SP (1997). Biology of the Springtails (Insecta: Collembola). Oxford: Oxford University Press. ISBN 0-19-854084-1

Web links

Commons : Springtails  - Album with pictures, videos and audio files
  • http://www.collembola.org/  : "To keep things simple, let's suppose the taxonomical speciation rate remains stable at the last 10-year speciation rate. Taking into account that the estimated number of Collembola species is about 50,000 (Hopkin 1998 : 118), collembolists will continue to describe new taxa for about 595 years ... " - scientific, very extensive page about springtails
  • Insects have two great mothers. On: Wissenschaft.de of March 21, 2003.