Large wing
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Common waterfly larva ( Sialis lutaria ) |
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| Systematics | ||||||||||
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| Megaloptera | ||||||||||
| Latreille , 1802 |
The megaloptera , also known as mud flies , are an order of insects . The closest relatives are the netwings (Neuroptera) and the camel neck flies (Raphidioptera). Of the 328 species described (as of 2008), only six live in Western Europe, and another five in Eastern Europe. The body length of the animals is between 23 and 35 mm, the species Acanthocorydalus kolbei can, however, be up to 70 mm long and reach a wingspan of a maximum of 160 mm.
Adults
The large-winged insects are relatively soft-skinned, elongated insects. The antennae are long with many regular links. The complex eyes are of medium size, the ocelles are absent in the family Sialidae. The pronotum is shield-shaped. The fore and hind wings are about the same size and quite similar to each other, they have a clearly protruding wing veining , which forms a net-like pattern through numerous cross veins. The wings are large and dark brown in color, they are placed like a roof over the body in the resting position. Most species are poor fliers and only cover short distances in flight. In some species of the subfamily Corydalinae from North America ( Corydalus ) and Asia ( Acanthacorydalis ) the mandibles are extended like a saber. Since the animals do not consume any food, the reason for this is unknown; it is assumed that this is caused by competition between the males in choosing a partner ( sexual selection ). The remaining species have relatively unspecialized mouthparts of the biting-chewing type.
The adult animals live in the bank vegetation of the waters in which they lived as larvae . They take in little fluid and otherwise no food. The lifespan of the adults hardly exceeds a week. The pairing of the mudflies takes place via chemical substances ( pheromones ) and vibrations. Mating takes place on the ground.
The females lay their 300 to 900 (rarely up to 2,000) eggs as clutches on hard structures near the water, e.g. B. reed plants, but also wood or stones. The clutch is single-layered and protected by a brown cement substance. The newly hatched larvae drop into the water and begin their aquatic life phase there.
Larvae
The first larval stage is free swimming (planktonic), the following ones live on the bottom of the water.
The larvae of the Sialidae are conspicuous by the feathered tracheal gills on the first seven abdominal segments and the long tail appendage (terminal filum); they are also quite large compared to other aquatic insect larvae. Depending on the species, the habitat is both fast-flowing waters with gravel and stone bottoms and slow-flowing or stagnant waters with sand or mud bottoms. The German name "Schlammfliegen" goes back to the most common species in Europe, Sialis lutaria , which prefers slowly flowing waters (name derived from Latin luturn: mud). The larvae of the Corydalidae have tracheal gill threads on the first eight abdominal segments, instead of the terminal filum they have paired appendages with claws.
All larvae are predatory and feed on various aquatic organisms, such as other insect larvae or annelid worms . The development takes one or two years, in cold waters such as mountain lakes three years, in some Chauliodinae from temporarily water-bearing waters up to five years. It runs over 10 larval stages.
Dolls
The pupation takes place on land in a self-dug hole in the ground waters nearby. The dolls do not have a doll shell, are already very similar in shape to the imago and are freely movable. The surface of the body has numerous thorns, which presumably serve to minimize direct contact with the soil. The puppet rest usually lasts 10 to 20 days.
Systematics of large wings
The species of large winged birds are divided into two families.
- Fam. Corydalidae . Widespread in America, Southeast Asia, South Africa, and Australia (Chauliodinae only).
- Unterfam. Corydalinae. 131 species.
- Unterfam. Chauliodinae. 116 species.
- Fam. Sialidae . 81 species. Especially in the mid-northern latitudes. North America, Europe, North Asia.
The species of Megaloptera documented in the European Union belong to the genus Sialis and are:
- Sialis fuliginosa Pictet , 1836
- Sialis lutaria ( Linnaeus , 1758)
- Sialis morio Klingstedt , 1932
- Sialis nigripes Pictet , 1865
- Sialis sibirica MacLachlan , 1872 (not in D)
- Sialis sordida Klingstedt , 1932
The subfamilies of the Corydalidae are considered by some taxonomists as independent families.
The monophyly of the Megaloptera as well as the families and subfamilies was confirmed in a study based on the mitochondrial DNA. Sister group of the Megaloptera would be the Netzflügler (order Neuroptera).
Fossil evidence
Fossil evidence of this insect order is very rare. The oldest fossils come from the Upper Permian of the Kuznetsk Basin (Russia) and belong to the families Permosialidae, Parasialidae and Tychtodelopteridae. These families are much closer to the recent Corydalidae than the Sialidae, which are only known from fossilized Eocene Baltic amber . The permosial larvae have nine pairs of tracheal gills, while their recent relatives have only eight pairs. Some fossil finds from the Mesozoic ( Upper Cretaceous ) are also inclusions in amber (place of discovery: Taimyr Peninsula , Siberia).
Individual evidence
- ↑ TS Vshivkova: Sialidae (Megaloptera) of Europe and the Caucasus. In: Entomological review. 64 (2) 1985, pp. 86-98.
- ↑ Yuyu Wang, Xingyue Liu, Shaun L. Winterton, Ding Yang (2012): The First Mitochondrial Genome for the Fishfly Subfamily Chauliodinae and Implications for the Higher Phylogeny of Megaloptera. PLoS ONE 7 (10): e47302. doi : 10.1371 / journal.pone.0047302
- ^ Weitschat & Wichard: Atlas of the plants and animals in the Baltic amber. Munich 1998.
- ↑ Müller: Textbook of Palaeozoology. Volume II, part 3, Jena 1978.
Web links
literature
- Matthew R. Cover, Vincent H. Resh: Global diversity of dobsonflies, fishflies, and alderflies (Megaloptera; Insecta) and spongillaflies, nevrorthids, and osmylids (Neuroptera; Insecta) in freshwater. In: Hydrobiologia. 595 (2008): pp. 409-417. doi : 10.1007 / s10750-007-9035-z
- JM Elliott: British freshwater Megaloptera and Neuroptera. A key with ecological notes. In: Freshwater Biological Association Biological Publication. No. 54 (1996), ISBN 0-900386-56-8
- Johann Gepp: State of research of the neuroptera larvae of the earth (with a key to the larval diagnosis of the families, an overview of 340 described larvae and 600 literature citations). In: J. Gepp, H. Aspöck, H. Hölzel (eds.): Progress in World's Neuropterology. Graz 1984, pp. 183-239.