Microscopy
Type of microscopes
Compound microscope
Stereoscope or dissecting microscope
Pollen
To look at pollen, you can use pollen from bee pollen loads (small amount mixed with a drop of water
and smeared across the slide) or from honey (about 10-fold dilution in water then spun down in a
centrifuge, or wait a week for pollen to precipitate to the bottom of the test tube).
Making slides from pollen is fairly
straightforward. It is much easier to carryout
successfully using glycerine jelly as the
mountant under the coverslip rather than
using one of the canada balsam substitutes.
It is even easier if the glycerine jelly
mountant has a small amount of basic
fuchsin dye dissolved in it. This will
automatically stain the pollen grains as part
of the slide mounting process.
You do not need to completely dry your
sample of pollen on the slide before staining.
You can smear the warmed stain-mountant mix on the coverslip and invert the nearly-dry slide with
pollen smear over it until it touches and flip it back over to let the coverslip settle down.
Veronica Owen
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To use glycerine jelly as a mountant it has to be heated. For a small amount of slide it is easier to
place the container into a cup of recently boiled water and it will melt quickly.
To make the preparation permanent, the edge of the coverslip needs to be sealed with a fine line of
nail varnish.
Testing for Acarine and Nosema
A sample of 30 bees is required to test a colony for adult bee diseases. These should be older forager
bees. The same sample can be used to test both Acarine and Nosema, if the Acarine test is carried
out first. The bees should be killed first using ethyl acetate.
Acarine requires a stereoscope and the bee should be pinned to a sloping block with double needle.
Both point of the needle should pass through the thorax between the second and third pair of legs.
Once surely in place, the head and first pair of legs are removed with forceps and then twisting. The
aim is to be left with the end of the thorax exposed horizontally under the microscope. The collar
segment should also be removed. The trachea in a healthy bee should appear pearly white. The
trachea in an infected bee will show a brown or black discolouration. Infected bees have
disjointed wings and crawl in front of the hive unable to fly before dying.
Nosema can be tested once acarine testing is completed. The
abdomen of 30 bees are put into a mortar and mashed up with
a drop of water. A tiny drop of the resulting brown liquid is
used to make a slide which can be inspected with a compound
microscope at 400x. If positive, nosema spores will be seen as
rice grains shapes approximately 5-8 µm (micrometers) long.
1 µm= 0.001mm
Veronica Owen
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