A Berlese funnel or Berlese trap is a device used to extract

desiccation Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container. The ...

-intolerant invertebrates from samples of

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

leaf litter Plant litter (also leaf litter, tree litter, soil litter, litterfall, or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that has fallen to the ground. This detritus or dead organic material and its constituen ...

. 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. Biologist

Antonio Berlese Antonio Berlese (26 June 1863, in Padua, Austrian Empire – 24 October 1927, in Florence) was an Italian entomologist. Career Berlese worked on pest insects notably of fruit trees. He published over 300 articles and a book ''Gli insetti loro o ...

first described such a device in 1905, using a hot water jacket as heat source. In 1918

Albert Tullgren Hugo Albert Tullgren (7 September 1874, in Stockholm – 1 July 1958) was a Swedish entomologist and arachnologist. In 1899 he received his bachelor's degree from Uppsala University, then from 1902 worked as an assistant at the National Entom ...

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. 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. Another variation uses

naphthalene Naphthalene is an organic compound with formula . It is the simplest polycyclic aromatic hydrocarbon, and is a white Crystal, crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 Parts-per notation ...

flakes or similar aromatic

mothball Mothballs are small balls of chemical pesticide and deodorant, sometimes used when storing clothing and other materials susceptible to damage from silverfish, Mold (fungus), mold or moth larvae (especially clothes moths like ''Tineola bissell ...

s in place of a heat source to drive organisms downward. 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.

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Further reading