Credit: Thomas Loynachan, PhD, Soil Biologist, Iowa State University
A berlese funnel is a device that is used to extract insects from soil samples. It uses a heat source (in this case a light bulb) to dry the sample, forcing the insects through a screen and into a jar of preserving fluid.
Here's what you need to make your own Berlese Funnel:
- a one-gallon plastic milk container (empty)
- an empty jelly jar (or a one-pint Mason jar) with a tight lid
- a stick -- about 25 cm long
- 1/4" mesh hardware cloth or aluminum window screen (15 X 15 cm)
- a pair of scissors
- masking tape or duct tape
- rubbing alcohol (ethyl) -- available at drug stores
- a gooseneck lamp (optional)
1. Cut the bottom out of the milk jug (Fig. 1) and turn it upside down over the Mason jar to make a funnel.
2. Tape the stick to the handle of the milk jug (Fig. 2) so it is just long enough to reach the outside bottom of the Mason jar.
3. Bend down the corners of the hardware cloth so it fits snugly inside the wide end of the funnel. If using window screen, cut and pinch numerous slits so larger animals can crawl through.
4. Collect several handfuls of humus or leaf litter and put them on top of the wire mesh.
5. Pour alcohol into the Mason jar to a depth of 1-2 cm.
6. Carefully set the funnel on top of the jar and tape the stick to the jar so it won't tip over.
7. Leave the funnel in a warm, quiet place where it won't be disturbed.
8. Set a lamp over the funnel to speed drying (see Fig. 3). Keep the lightbulb at least 10 cm away from the funnel.