Eclector

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Flight sticker in a research project to investigate the effects of light pollution on flight insects

An eclector (from Greek eklegein = "to read out") is a trap for catching arthropods such as insects or spiders . The specific types of eclectors are each adapted to the way of life and movement of the animals that are to be caught with them. The animals caught with the eclectors can then be identified and counted. Eclectors belong to the so-called automatic traps or "automatic traps" which, once deployed in the area, collect organisms without further involvement of the examiner and only have to be emptied periodically. Eclectors can be used as a method for quantitative sampling, i.e. not only determine the species spectrum, but also the population density of the organisms examined.

Floor eclectors

A floor eclector is a mostly box-shaped or tent-shaped trap for the quantitative detection of the insects hatching from a certain floor area. It usually consists of a frame with an attached tent-like construction made of dark material, which tapers towards the top, with a transparent head box in which the winged imagines of ground-living insects that hatch from the ground and strive for light collect and are killed with a trapping liquid. Since the trap type exploits the phototactic reaction of the insects that strive for light , it is also referred to as a photo eclector. The insects caught with a soil photo-ejector are so-called strata changers, which at some point during their life cycle switch from the stratum of the soil to the higher strata (field layer, herbaceous layer or tree canopy). This applies to most insects living on the ground, which almost always have an airworthy stage of spread. One advantage of the method is that mainly adults are caught, which are usually easier to identify than the larval stages living in the ground . For quantitative recording, the eclector is left to stand over the entire period of activity (or an entire year) and the catches made during this period are added up over time. This means that all imagines hatching from the trap area are recorded. Their frequency can then be extrapolated based on the area of ​​the trap. Usually the hard plastic walls of the eclectic are buried in the ground to prevent them from escaping sideways. In addition, a floor trap is often used to capture individuals walking on the floor surface.

Soil photo-collectors belong to the standard methodology, especially when studying the fauna of forest ecosystems. They were introduced and used extensively in the Solling project on ecosystem research as part of the International Biological Program and its follow -up projects . Up to 10,000 arthropods per square meter, which are distributed in 870 species, were caught here with a single floor photo-ejector of one square meter. Because of the effort involved, the method is mostly only used in the context of scientific research programs. There are occasional missions in the context of applied questions, for example to detect damage thresholds of the oak moth , a forest pest.

Tree eclectors

A tree eclector (also called a trunk eclector) is a catching device that is attached in a ring around a tree trunk and is open at the bottom. Usually it consists of three or four funnel-shaped parts, which taper upwards into a collecting box similar to the floor eclector, and which together encompass the entire trunk. The tree eclector is used to catch stratiform insects, which spend a stage of life in the treetops and to reach them run up the tree trunk or fly close to it. Tree eclectors record numerous species of the two-winged bugs , beaked beetles , springtails , beetles and spiders , which are difficult to detect with other methods due to their way of life and are therefore almost indispensable if a complete spectrum of species in a forest ecosystem is sought. Since almost all Central European arthropod species of the tree canopy visit the soil layer at some stage of development (e.g. for wintering), it is also useful to determine the fauna of the tree canopy, which is difficult to detect in any other way.

Flight stickers

Flight eclectors (also called air eclectors) are a variant of the window trap . They usually consist of plexiglass panes arranged in a cross shape, which are fixed at right angles to each other so that eight catch surfaces are created. Flying insects collide with the pane, fall down and are caught in a funnel-shaped collecting device with a collecting vessel on the ground and killed here. Often there is another catch funnel at the upper end of the disc cross to catch any insects crawling upwards. Air eclectors are often pulled up into the canopy of forests, attached to ropes, in order to examine the fauna of the treetops. They are particularly suitable for active, swarming species. When examining tree canopy beetle species, this method provides the highest number of species in a comparison of methods. They were also developed in the Solling project and used on a large scale.

In addition to the types described, other designs of eclectors are used less often, for example deadwood eclectors, in which a deadwood sample is introduced into an eclector in order to catch hatching insects. The same technique is also used when examining bodies of water, but here referred to as the emergence collection trap (or simply emergence trap).

Individual evidence

  1. ↑ Kenneth W. McCravy (2018): A Review of Sampling and Monitoring Methods for Beneficial Arthropods in Agroecosystems. Insects 9, 170. doi: 10.3390 / insects9040170
  2. ^ Keyword Eklektor, in Matthias Schaefer: Dictionary of Ecology. Spectrum Akademischer Verlag, Heidelberg, 5th edition 2012. ISBN 978-3-8274-2561-4
  3. ↑ a b c K. Winter, H. Bogenschütz, D. Dorda, WHO Dorow, G. Flechtner, U. Graefe, F. Köhler, N. Menke, J. Schauermann, H. Schubert, U. Schulz, J. Tauchert : Program to study fauna in natural forests. IHW-Verlag, Eching 1999. ISBN 3-9301 67-36-0
  4. ↑ Gerhard Weidemann: The structure of animal communities. In: Heinz Ellenberg, Robert Mayer, Jürgen Schauermann: Ecosystem Research. The results of the Solling project 1966-1986. Eugen Ulmer Verlag, Stuttgart 1986. ISBN 3-8001-3431-4
  5. ↑ R. Grimm, W. Funke, J. Schauermann (1974): Minimal program for ecosystem analysis: Investigations on animal populations in forest ecosystems. Negotiations of the Society for Ecology (Erlangen 1974): 77-87.
  6. ↑ Horst Delb (2016): Monitoring and forecasting harmful organisms in the forest: a core task of forest protection. FVA-Insight (Forest Experimental and Research Institute Baden-Württemberg) 1/2016: 4-9.
  7. ↑ Heinz Bußler, Jörg Müller, Ulrich Simon (2004): Recording xylobiont beetles in forest ecosystems. A comparison of methods with special consideration of the crown fauna. Nature conservation and landscape planning 36 (7): 197-201.
  8. ^ W. Funke (1976): The zoological research program in the Solling project. Negotiations of the Society for Ecology (Gottingen 1976): 49-58.

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