Berlese funnel

A Berlese funnel or Berlese trap is a device used to extract desiccation-intolerant invertebrates from samples of soil or leaf litter. It works by creating a desiccation gradient over the sample such that mobile organisms will move away from the dry environment and fall into a collecting vessel, where they are preserved for examination.

A funnel (E) contains a sample of soil or leaf litter (D), and a heat source (F), in this case an electric lamp (G), heats the sample. Animals escaping from the desiccation of the sample descend through a filter (C) into a preservative liquid (A) in a receptacle (B). This illustration is merely a schematic, since usually the soil sample will not be crumbled and poured into the funnel (this would inevitably lead to a high amount of soil particles in the preservation fluid requiring laborious work to sort out the soil organisms). In fact, the soil sample is placed on a mesh sieve that will allow the soil animals to pass but should retain most of the soil particles.

Biologist Antonio Berlese first described such a device in 1905, using a hot water jacket as heat source.^[1] In 1918 Albert Tullgren described a modification, where the heating came from above by an electric bulb and the heat gradient was increased by an iron sheet drum around the soil sample.^[2] For this reason the term Tullgren funnel is also used. A modern funnel usually combines elements from both methods and thus may be referred to as a Berlese-Tullgren funnel.^[3]

Another variation uses naphthalene flakes or similar aromatic mothballs in place of a heat source to drive organisms downward.^[4] This method finds application in situations without electrical power, where the organisms are repulsed by volatile preservatives in collection container, or they cannot migrate downward quickly enough to avoid succumbing to desiccation.

See also

• Insect collecting
• Soil biology

References

1. Berlese, Antonio (1905). Apparecchio per raccogliere presto ed in gran numero piccoli Artropodi [Apparatus for gathering small arthropods quickly and in large numbers] (in Italian). pp. 85–90. OCLC 79048180.
2. Tullgren, A (26 August 2009). "Ein sehr einfacher Ausleseapparat für terricole Tierformen" [A very simple device to select for soil-dwelling animals]. Zeitschrift für Angewandte Entomologie (in German). 4 (1): 149–150. doi:10.1111/j.1439-0418.1918.tb00820.x.
3. Southwood, T.R.E. (1994). Ecological methods. Chapman & Hall. ISBN 978-0-412-30710-2.^{[page needed]}
4. Brown, Richard D. (15 March 1973). "Funnel for Extraction of Leaf Litter Organisms". Annals of the Entomological Society of America. 66 (2): 485–6. doi:10.1093/aesa/66.2.485.

Further reading

• Smith, L. B. (31 May 2012). "Efficiency of Berlese-Tullgren funnels for removal of the rusty grain beetle, Cryptolestes ferrugineus, from wheat samples". The Canadian Entomologist. 109 (4): 503–9. doi:10.4039/Ent109503-4.
• Dondale, C. D.; Nicholls, C. F.; Redner, J. H.; Semple, R. B.; Turnbull, A. L. (31 May 2012). "An improved Berlese-Tullgren funnel and a flotation separator for extracting grassland arthropods". The Canadian Entomologist. 103 (11): 1549–52. doi:10.4039/Ent1031549-11.
• Crossley, D.A.; Blair, John M. (February 1991). "A high-efficiency, 'low-technology' Tullgren-type extractor for soil microarthropods". Agriculture, Ecosystems & Environment. 34 (1–4): 187–92. doi:10.1016/0167-8809(91)90104-6.
• Hubert, Jan; Nesvorna, Marta; Stejskal, Vaclav (October 2009). "The efficacy of sieving, filth flotation and Tullgren heat extraction for detecting various developmental stages of Tribolium castaneum and Ephestia kuehniella in samples of wheat grain, flour and semolina". Journal of Stored Products Research. 45 (4): 279–88. doi:10.1016/j.jspr.2009.05.003.
• Wheeler, Quentin D.; McHugh, Joseph V. (1987). "A Portable and Convertible 'Moczarski/Tullgren' Extractor for Fungus and Litter Coleoptera". The Coleopterists Bulletin. 41 (1): 9–12. JSTOR 4008312.
• Harris, Marvin (15 October 1971). "Sampling Pear Foliage for Nymphs of the Pear Psylla, Using the Berlese-Tullgren Funnel". Journal of Economic Entomology. 64 (5): 1317–8. doi:10.1093/jee/64.5.1317.
• Besuchet, Claude; Burckhardt, Daniel H.; Löbl, Ivan (1987). "The 'Winkler/Moczarski' Eclector as an Efficient Extractor for Fungus and Litter Coleoptera". The Coleopterists Bulletin. 41 (4): 392–394. JSTOR 4008527.