Dissecting Honey Bees


The following equipment is required to perform dissection of honey bees.

Dissection Microscope, Scissors, Forceps, Scalpel, Mounting Needles, Pipette, L Shaped Rod, Spirit Lamp, Petri Dish and Wax.

Image 1

To support the soft internal organs of the honeybee dissection needs to be carried out under dissection fluid. Isopropyl alcohol is used.  Mix with water 30 parts by volume with 70 parts clean water.

A fresh batch is best for each session.

Bees for dissection can be collected from your frames using a matchbox or you can collect them at the entrance using a honey jar.

Chloroform or ethyl acetate can be used to kill the bees, a piece of filter paper is wetted with the killing fluid and this is then slid into the box or jar. When the buzzing ceases your bees are ready.

It is preferable to only use fresh bees for dissection, internal structures decay very quickly. Bees may also be frozen to kill them but the subsequent thawing can damage soft internal tissue.

Prior to their use bees can be preserved and stored almost indefinitely in isopropyl alcohol.

To mount your bees for dissection melt clean beeswax and pour into the petri dish, allow this to set. Remove the legs and wings from the bee using fine scissors. Create a narrow channel in wax using a heated L shaped rod, place the bee in the molten channel taking care to stretch the bee out as straight as you can then use the heating rod to mound molten wax against each side of the bee so that it is held firmly.

Fill the tray with dissection fluid so that the bee is covered.

Image 2

DISSECTION OF THE ABDOMEN

To dissect the abdomen place the Petri dish under the dissection microscope, adjust the light and focus  and then, using scissors or scalpel, cut around the dorsal surface. Cut as indicated below rotate the Petri dish to aid cutting into the abdominal plates. Ensure you do not cut too deeply.

Image 3

Once the top of the abdomen is removed the heart will usually be visible on the underside.  The dorsal diaphragm should also be recognisable. There may be a large number of small creamy coloured bodies (fat bodies) around the heart.

The heart can be removed and placed on a slide for examination on the high powered compound microscope.

Image 4

To display the alimentary canal (digestive system) carefully remove the tracheal sacs using forceps. You now have an opportunity to identify the organs without disturbing them. The rectum and the honey/crop stomach can be clearly seen. If the rectum has been ruptured its contents can be removed using a pipette.

To display the digestive system using needles in each hand pass them under the ventriculas and the rectum. The alimentary canal needs to be slightly lifted and then gently tease the viscera and lay them to the side of the bee.

Image 5

 

DISSECTION OF THE THORAX

Dissection of the thorax enables you to expose the flight muscles and the thoracic glands. If the bee has been preserved in isopropyl alcohol this makes dissection easier as the flight muscles are hardened. The dorsal surface of the thorax is removed using a fine scalpel.  A slit is made in the body wall then you cut in a circular motion. A longitudinal slit is made along the mid-line.

The attached muscle fibres can be teased away from the underside of the detached exoskeleton with the point of the scalpel blade.

It can be seen how the direction of the muscle fibres influence the movement of the wings.

To expose the thoracic glands use blunt tipped forceps to grab bunches of the muscle fibres and pull them carefully from the thorax. Once the muscle fibres have been removed the oesophagus and the thoracic salivary glands can be observed.

With careful dissection the aorta can be observed this is very fine and is often destroyed during the removal of the flight muscles

 

DISSECTION OF THE HEAD

The dissection of the head exposes the hypopharyngeal glands.

There are two methods of mounting the head for dissection, it can be mounted in wax as described above or fixed to a microscope slide using superglue. If mounted in wax the head should be covered with dissection fluid.

Using a fine scalpel cut through the wall of the face (mask), across the vertex, around the compound eyes and round the edges of the mask. The mandibles, labrum and clypeus are not included.

Cut off the antennae close to the point of attachment. Using the point of the scalpel lift of the mask and disengage the underlying tissue.

The hypopharyngeal glands can now be lifted out and examined.

 

 

Dissection Images

Jack Simpson http://beeblog.com.au/dissecting-the-abdomen-of-the-honey-bee/