The Sting
Margaret Thomas NDB
Scientific Beekeeping
Scientific Beekeeping
info@scientificbeekeeping.co.uk
The Sting
November diet of external anatomy – the sting, an organ most of us are probably familiar with!
The sting is housed in the sting chamber at the rear of the abdomen. To activate the sting the tip of the abdomen is swung down into an almost vertical position. The shaft which normally encloses the sting mechanism is swung upwards.

On each side the sting comprises of 3 main plates. The lower plate, the oblong plate is fixed and does not move. This plate is continuous with the 2nd ramus which arches backwards to run continuously with the central rod of the bulb and merge to form one stylet.

The upper plate, the quadrate plate, is mobile and is moved backwards and forwards by the protractor and retractor muscles.

The triangular plate is continuous with the 1st ramus, a long curved rod which arches backwards to run continuously with the lancet.

The quadrate plate articulates with the top of the triangular plate. When the quadrate plate is pulled backwards the triangular plate rocks on the oblong plate, the movement is transferred to the arching ramii causing retraction of the lancets. Equally when the quadrate plate is pulled forwards by the protractor muscles the triangular plate rocks forwards and the lancet is protracted.

The 1st ramus is grooved and runs on a track like ridge formed by the 2nd ramus. The ramii enter the bulb and exit to form the two lancets and one stylet. The track and groove of the stylet and lancets allow the two lancets to glide smoothly back and forth, alternately.

The bulb is a sac like structure lying between the oblong plates and holds the venom produced by the venom gland. The venom is propelled down through the bulb by a structure attached to each lancet, called the umbrella valve, into a central canal formed by the two lancets and the stylet.

When a honey bee stings a soft bodied animal the backward facing barbs on the lancets are stuck, giving purchase for the other lancet to penetrate deeper into the wound. This means that when the bee flies away the whole sting apparatus is torn away from the body of the bee, complete with its own ganglia allowing it to continue to function. The queens sting is curved and the barbs are rudimentary so they are able to sting repeatedly though they are reluctant to sting anything other than another queens.

As the sting apparatus is loosely fixed in the bee, the lining of the sting chamber is disrupted, thus dispersing the major alarm pheromone isoamyl acetate (also known as isopentyl acetate). This alerts other bees to investigate and sting in the same area. Great way to send a bear running away, but painful to us humans.
Beekeepers use the smoker, and smoke the area stung to disperse the alarm pheromone.


This information is based on an article that appeared in the Scottish Beekeeper Magazine in 2017
Bee Venom
The defensive response of the honeybee Apis mellifera
Nouvian et al 2016