Common mayfly
| Common mayfly | ||||||||||
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Common mayfly female |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Ephemera vulgata | ||||||||||
| Linnaeus , 1758 |
The common mayfly or brown mayfly ( Ephemera vulgata ) is a mayfly from the Ephemeridae family .
features
Adults
The species of the genus Ephemera have transparent wings with a conspicuous, brown markings along some transverse veins of the forewing. In Ephemera vulgata , the wings often appear a bit brownish with a dark network of veins. As with most mayflies, there are three tail threads at the end of the abdomen. The species of the genus can only be determined from the penis lobes of the males and above all from the drawing of the abdomen. In Ephemera vulgata the yellowish abdomen has two dark, elongated spots on top of all segments that are triangular (with the base facing forward). In addition, on the back shields (tergites) 7 to 9 sit in between two narrow, long lines. Males reach a body length of 15 to 21 millimeters, with tail threads 30 to 35 mm, the females are slightly longer with 17 to 24 millimeters, but have shorter tails, which they measure only 22 to 27 millimeters in total. The fore wing length of the males is 15 to 17 millimeters, that of the females 18 to 23 millimeters.
Larvae
The larvae are 16 to 18 millimeters long. They also have three tail threads with which they become 22 to 30 millimeters long, legs and tail threads are quite short due to the burrowing way of life. They are yellowish white in color with dark markings. On the abdomen are seven pairs of tracheal gills, which consist of two-branched, narrow lamellae with feather-like fringes on the edge. The gills are attached to the sides of the abdomen and extend diagonally backwards over the top of the abdomen, so that they mainly lie on their back, they do not protrude laterally. The head of the animals is conspicuous by a thorn-shaped tooth of the mandibles protruding far forward, the teeth are smooth and slightly curved outwards, they serve as digging tools.
The larvae have a striking dark mark on the upper side of their abdomen (hidden by the gills in life!), Which is similar to that of the adults and can also be used to identify the species. (The drawing lies below the cuticle and fades on preserved animals.) In contrast to Ephemera lineata and Ephemera glaucops , the posterior abdominal segments (six to nine) have a brown markings made up of a pair of lateral broad and a pair of inner thin longitudinal stripes. In contrast to Ephemera danica , the anterior abdominal tergites are drawn similarly, while in danica they have at most small dots. In addition, the tibia of the forelegs in danica has a tooth-shaped extension on the outside, which vulgata is missing.
Way of life
The larva of Ephemera vulgata lives burrowing in the bottom of the water, in which they dig small U-shaped tunnels with their mandible processes and short, strong front legs, in which they live. The larva creates a stream of water through the tunnel, from which it filters out food particles with its mouthparts. They can also rummage through the sediment for food or collect washed-up material from the surface. Food is fine, dead organic matter, mainly of vegetable origin ( detritus ). The species predominantly has a two-year development cycle in Central Europe (semivoltin), i. H. the larvae overwinter once and only hatch in the second year after oviposition. The hatching larva can be ascended from the bottom to the surface of the water, it sheds its skin on the surface and then flies up directly. Hatching occurs during the day, mostly around noon, often synchronized as a mass hatch of numerous individuals at the same time. As is typical for all mayflies, the out-flying subimago (with milky, hairy wings) sheds its skin once more away from the water to become an imago.
In the case of ephemera species, the males form swarms that usually fly away from the water. In contrast to Ephemera danica , vulgata does not swarm in the treetops, but just above the ground. The females fly into these flocks of males to mate. The pairing takes place in flight. The female lays the fertilized eggs in flight. It rushes down to the surface of the water in a zigzag flight, dips the tip of the abdomen into the water and allows the oozed eggs to be rinsed off, which are distributed on the bottom of the water. After all eggs have been laid, it falls dead to the ground or mostly still on the surface of the water. The adults only live for a few days and do not ingest any food during this time.
habitat
The larvae of Ephemera vulgata live on the bottom of both flowing and standing water. To dig in, they need bodies of water with a sand or mud bottom. The species occurs widespread in lakes, but avoids small bodies of water such as ponds or ponds. In flowing waters it prefers large, slow flowing rivers ( Potamal ), it does not normally occur in streams. She avoids waters with stronger currents. Today it can be found widely in numerous shipping canals.
The species is not very sensitive to organic water pollution, its saprobic index is 2.3, so it can still survive in moderately polluted rivers. Today, however, it is less common on rivers than on stagnant water due to the increased pollution and water construction. In lakes, it cannot survive in heavily polluted (hypertrophic) bodies of water because the bottom of the lake is oxygen-free.
Ephemera vulgata needs neutral or alkaline waters and cannot survive in acidic waters.
distribution
The species lives in almost all of Europe, from northern Norway to Greece, it is also found in Anatolia. It is only absent in Ireland and Iceland. In the Alpine countries and large parts of Southeast Europe, however, it is considered rare. In Central Europe, it has become rarer regionally due to the degradation of the major rivers and streams.
swell
- Ernst Bauernfeind, Uwe H. Humpesch: The mayflies of Central Europe (Insecta: Ephemeroptera). Destination and ecology. Verlag des Naturhistorisches Museum Wien, 2001, ISBN 3-900275-86-6 .
- Denise Studemann, Peter Landolt, Michel Sartori, Daniel Hefti, Ivan Tomka: Ephemeroptera. (= Insecta Herlvetica Fauna. Volume 9). Published by the Swiss Entomological Society, 1992, DNB 940939762 .
- JM Elliot, UH Humpesch, TT Macan: Larvae of the British Ephemeroptera. (= Freshwater Biological Association Scientific Publication. No. 49). Freshwater biological Association, 1988, ISBN 0-900386-47-9 .
- A. Buffagni, DG Armanini, M. Cazzola, J. Alba-Tercedor, MJ López-Rodríguez, J. Murphy, L. Sandin, A. Schmidt-Kloiber: Ephemeroptera Indicator Database. Euro-limpacs project, Workpackage 7 - Indicators of ecosystem health, Task 4, 2007. (freshwaterecology.info , version 5.0, accessed February 6, 2013).
Individual evidence
- ↑ Ann Kristin Schartau. S. Jannicke Moe, Leonard Sandin, Ben McFarland, Gunnar G. Raddum: Macroinvertebrate indicators of lake acidification: analysis of monitoring data from UK, Norway and Sweden. In: Aquatic Ecology. Volume 42, 2008, pp. 293-305. doi: 10.1007 / s10452-008-9186-7
Web links
- Ephemera vulgata at Fauna Europaea