Berlese funnel

Definition

A passive extraction device used to collect small, desiccation-intolerant invertebrates—especially microarthropods such as mites, springtails, and small insects—from soil, leaf litter, or other substrate samples. The apparatus creates a directional desiccation gradient: a heat source (typically an incandescent lamp) dries the sample from above, driving mobile organisms downward through a mesh screen into a collecting vessel filled with preservative fluid. Organisms that cannot tolerate arid conditions actively escape the drying zone and are trapped for preservation and subsequent identification.

Etymology

Named for Italian entomologist Antonio Berlese (1863–1927), who developed the technique in the early 20th century

Example

A soil ecologist places a 500 cm³ core of forest floor litter into a Berlese funnel with a 2 mm mesh screen, positions a 25-watt lamp 15 cm above the sample, and leaves the apparatus for 72 hours to extract oribatid mites and collembolans into a vial of 70% ethanol for community analysis.

Synonyms

• Berlese trap
• Tullgren funnel

Related Terms

• Tullgren funnel
• Winkler extractor
• pitfall trap
• leaf litter sampling
• microarthropod
• soil fauna extraction

Usage Notes

Specialists often distinguish the Berlese funnel (using heat and desiccation) from the Tullgren funnel (using a drying, heated column with a more gradual gradient), though the terms are frequently conflated in practice. The method preferentially extracts active, mobile taxa and underestimates desiccation-tolerant species, cyst-forming nematodes, and sessile organisms. Extraction efficiency varies with lamp wattage, mesh size, duration, and substrate moisture; standardization is critical for comparative community studies. The apparatus is unsuitable for collecting aquatic microfauna or specimens needed for live behavioral observation.