Extracting endogeous microarthropods: A new flotation method using 1,2-dibromoethane

Many methods have been proposed for extracting soil microarthropods. They are generally well adapted for specific substrates and taxonomical groups. Flotation in saturated aqueous salt solutions was tested and should not be used. Carbon tetrachloride flotation and LUDOX(TM) methods were found to be unable to extract microarthropods from loamy soil samples. Therefore, a new flotation method using 1,2-dibromoethane (DBE) was set up. It was especially efficient for soft-bodied animals and deep soil samples, which usually are very difficult to process. The method applies to any soil with low organic content, including most cultured soils. It was found to extract five times more microarthropods and 1.5 more taxa than a classic dry funnel method. Its absolute efficiency varied from 41 to 100 % depending on the taxa and stase. As DBE is hazardous, special precautions have to be taken when handling the product. (C) Elsevier, Paris.