Chaetopteryx villosa

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Chaetopteryx villosa
Chaetopteryx villosa

Chaetopteryx villosa

Systematics
Order : Caddisflies (Trichoptera)
Subordination : Integripalpia
Family : Limnephilidae
Subfamily : Limnephilinae
Genre : Chaetopteryx
Type : Chaetopteryx villosa
Scientific name
Chaetopteryx villosa
( Fabricius , 1798)

Chaetopteryx villosa ( Fabricius , 1798) is a species of the family Limnephilidae , which belongs to the order of the caddis flies (Trichoptera). The species is widespread and frequent in Europe, the main area of ​​distribution is in streams ( Rhithral ).

features

Adults

Chaetopteryx villosa reaches a body length of 5 to 10 millimeters, the wingspan is between 15 and 27 millimeters (females) and 13 to 25 millimeters (males). The body, including the wings, is predominantly yellow-brown in color, the top of the head, antennae and palpi are reddish. The males do not have a spur, the females have a spur, the middle and rear splints each have three spurs (long, thorn-like appendages), the head next to the large complex eyes three ocelles and the maxillary palps consist of three limbs. It is typical of the genus that the veins and the membrane of the forewings are covered with stiff, dark bristle hairs, each of which arises from a wart-like halo. The species can only be distinguished from related species on the basis of its genital morphology; in case of doubt, females cannot be identified down to the species.

Larvae

The larvae belong to the caddis flies with the so-called "eruciform" larval type, i. That is, they resemble caterpillars in body shape, the head is vertical. In life they are enclosed in a cylindrical, straight to slightly curved quiver. The quiver consists of plant detritus such as wood and pieces of leaf, small stones or coarse sand in varying proportions, whereby younger larvae tend to build plant quivers, older ones more and more stone ones. However, the shape of the quiver is highly variable depending on the habitat and material available; it cannot be used to identify genus or species. On the trunk section, as in many related species, the upper side of the first segment (pronotum) and the second segment (mesonotum) are covered with sclerites , the third segment (metanotum) is predominantly soft-skinned and carries a group of six small sclerites characteristic of the family . It also has three non-sclerotized humps that hold the quiver in place in life. The abdomen is not sclerotized and has tubular gills made of single filaments on all segments. The pronotum has a distinctive transverse furrow in the front third. The determination up to the species is only possible in the last larval stage according to certain features of the bristling (chaetotaxia) and the presence and shape of some small sclerites. It is only possible under the microscope, it is always uncertain and difficult even for experts.

distribution

Chaetopteryx villosa is a species of northern and central Europe and parts of the northern Mediterranean region. It occurs in Great Britain and Ireland . In continental Europe, their occurrence extends from the Atlantic coast in the west to the central and northern part of European Russia in the east. The northern limit of the distribution is in northern Scandinavia. The southern border is partly difficult to indicate because of the occurrence of very similar, closely related species. In the contact areas of these vicarious species there is also the formation of intermediate forms, possibly hybrids . Such are already known from Austria with Chaetopteryx fusca . The species lives in the north of the Iberian Peninsula without the extreme northwest (with the subspecies gonzalesi ), in southern France, the Alpine countries and the north of the Balkan Peninsula. It has not been proven in Italy.

In Germany it is widespread and frequent in the low mountain range. It is widespread in the lowlands, but less common overall. She is not endangered.

Life cycle

Adults of the species fly late in the year, in late autumn, and winter. Flight times are given, for example: for Norway from mid-September to mid-October, for England from October to January, for Mecklenburg-Western Pomerania from October, for Poland from the end of September to mid-December. The species usually has one generation a year ( univoltin ), but in northern Norway a generation sometimes takes two years to develop (semivoltin). The animals hatch with mature gonads and mating occurs very soon after hatching. This is unusually long and can last up to twelve days. Immediately afterwards, the eggs are laid. The eggs are laid outside the water, near the waterline, preferably on the underside of moss-covered dead wood that has fallen into the water. They form flat egg clutches that are covered by a putty-like protective layer. Larvae hatch soon after egg-laying, sometimes in autumn, and throughout winter, some not until later in spring. The hatched young larvae drop into the water and live on the bottom of the water. The species has five larval stages. The finished larvae pupate within their larval quiver on the bottom of the water, for this purpose the quiver is spun to the base with silk threads. The development is variable depending on the temperature and the time of hatching. Fast-developing larvae pupate as early as April and lie in pupal rest all summer, slower-developing larvae continue to grow until late summer.

Ecological demands

Chaetopteryx villosa is rheophilic to limnophilic; this means that the larvae live in flowing, preferably slower flowing, but up to standing water. It prefers to live in streams (limnological zone of the Rhithral ), where it can be one of the most common caddisfly species, but occurs in suitable habitats from the source ( Krenal ) to the upper reaches of the large rivers ( Epipotamal ). It is also not picky about the altitude distribution, occurrences from the planar altitude level (the plain) to the subnival altitude level (mountains above the tree line) are known. It clearly prefers hard substrates and occurs preferentially in bodies of water with a gravel or stone base, on soft substrates only where hard structures are available due to fallen leaves and dead wood; it is absent on a pure sand or muddy bottom. It is more common in acidic waters than in basic ones. She has different strategies for nutrition. Either it eats the partially decomposed fallen leaves that have fallen into the water, or it scrapes the biofilm of algae and bacteria from the surface of stones and other hard substrates; in addition, it can use fine plant detritus that is washed up in quiet bays.

The species is able to endure slightly to moderately polluted waters. It occurs in unpolluted up to moderately polluted to critically polluted waters ( water quality class II to II-III). Due to its Eurocean claims, it is not considered as an indicator type in the German saprobic system .

Taxonomy and systematics

The species was first described by Johann Christian Fabricius in 1798 as Phryganea villosa . A distinction is made between two subspecies: The nominate form Chaetopteryx villosa villosa lives in the greater part of the distribution area, Chaetopteryx villosa gonzalesi Botosaneanu, replaced in 1980 on the Iberian Peninsula, south of the Pyrenees. It makes with the seven types Chaetopteryx fusca Brauer 1857, Chaetopteryx sahlbergi McLachlan 1876 Chaetopteryx bosniaca Marinkovic 1955 Chaetopteryx atlantica Malicky 1975 Chaetopteryx gessneri McLachlan 1876 Chaetopteryx vulture Malicky 1971 Chaetopteryx trinacriae Botosaneanu, Cianficconi & Moretti 1986 Chaetopteryx villosa group of species . All of these species are allopatric with vicarious distribution. Since they develop transitional shapes to one another in the contact zones, it is also suggested that they possibly be viewed as subspecies of a broader species; however, this has not yet been proposed formally taxonomically. The contact zone of Chaetopteryx villosa and Chaetopteryx fusca runs through Austria (east of the city of Linz ), Slovakia (both species have been reliably identified here as well) and the south of Poland (Beskids). Since the larvae cannot yet be determined up to the species, the species specification in the contact zone is often uncertain.

literature

  • Ralf Bochert, Steffen Biele: A contribution to the knowledge of the Trichoptera fauna of Mecklenburg-Western Pomerania: Warbel and Thürkower Bach. In: Lauterbornia. 55, 2005, pp. 25-34 ( PDF on ZOBODAT ).

Web links

Individual evidence

  1. ^ F. Schmid (1952): Le groupe de Chaetopteryx (Limnephilidae, Trichoptera). Revue Suisse de Zoologie Tome 59, Fascicule 1: 99-172. Chaetopteryx villosa scan on p.122 at Biodiversity Heritage Library
  2. ↑ a b Wolfgang and Dagmar Tobias (1981): Trichoptera Germanica, identification tables of the German caddis flies. Part 1: Imagines. Courier Research Institute Senckenberg 49: 1-671. Generic code online at Trichoptera RP, by Peter Neu
  3. ↑ Hans Malicky: Atlas of the European caddis flies. Dr W. Junk Publishers, The Hague, Boston, London, 1983 ISBN 90-6193-134-7
  4. ↑ Johann Waringer, Wolfram Graf: Atlas of Central European caddisflies. Erik Mauch Verlag, Dinkelscherben, 2011. ISBN 978-3-00-032177-1
  5. ↑ a b c d Graf, W., Murphy, J., Dahl, J., Zamora-Muñoz, C., López-Rodríguez, MJ (2008): Distribution and Ecological Preferences of European Freshwater Organisms. Volume 1 - Trichoptera. Edited by Schmidt-Kloiber, A. & D. Hering. Pensoft Publishers (Sofia-Moscow). 388pp. online at www.freshwaterecology.info (registration required)
  6. ↑ SGLepneva: Fauna of the USSR Trichoptera Volume II No. 2. Larvae and Pupae of Integripalpia. Zoological Institute of the Academy of Sciences of the USSR New Series No. 95 Published for the Smithsonian Institution and the National Science Foundation. Washington, DC by the Israel Program for Scientific Translations. 1966, translated 1971
  7. ^ Hans Malicky (2005): An annotated directory of the caddis flies (Trichoptera) of Europe and the Mediterranean area. Linz biological contributions 37/1: 533-596.
  8. ↑ N. Bonada, C. Zamora-Muñoz, M. Rieradevall N. Prat (2004): Trichoptera (Insecta) collected in mediterranean river basins of the Iberian Peninsula: Taxonomic remarks and notes on ecology. Graellsia 60 (1): 41-69.
  9. ↑ Omar Lodovici, Marco Valle (2007): New data on the genus Chaetopteryx in Northern Italy and a description of C. moretta sp.n. Braueria 34: 15-16.
  10. ↑ Franz Klima, et al. (1994): The current risk situation for caddis flies in Germany (Insecta, Trichoptera) Nature and landscape 69 (11): 511-518.
  11. ↑ a b T. Andersen, Å. Tysse, (1984): Life cycle of Chaetopteryx villosa (Fabricius, 1978) (Trichoptera: Limnephilidae) in a lowland and a mountain stream in western Norway. Aquatic Insects 4: 217-232.
  12. ↑ a b J.M. Elliott (1971): Life Histories and Drifting of Three Species of Limnephilidae (Trichoptera). Oikos, Vol. 22, No. 1: 56-61.
  13. ↑ Ralf Bochert and Steffen Biele (2005): A contribution to the knowledge of the Trichoptera fauna of Mecklenburg-Western Pomerania: Warbel and Thürkower Bach. Lauterbornia 55: 25-34.
  14. ↑ a b c Katarzyna Majecka, Janusz Majecki, Anna Walaszek (2011): Important life history traits of Chaetopteryx villosa (Fabricius, 1798) (Trichoptera, Limnephilidae). Zoosymposia 5: 288-296.
  15. ↑ Hans Malicky, Steffen U. Pauls (2012): Cross-breeding of Chaetopteryx morettii and related species, with molecular and eidonomical results (Trichoptera, Limnephilidae). Annales de Limnologie - International Journal of Limnology 48: 13-19. doi: 10.1051 / limn / 2011054
  16. ↑ cf. Johann Waringer, Wolfram Graf, Hans Malicky (2013): The larva of Psilopteryx psorosa (Kolenati 1860) (Trichoptera: Limnephilidae) with notes on ecology and zoogeography. Zootaxa 3694 (6): 579-586.