Margaret Thomas NDB
Scientific Beekeeping
Scientific Beekeeping
Diagrams redrawn by Jackie Elliott

This information is based on an article that appeared in the Scottish Beekeeper Magazine in July 2017
Image 3 : Mouthparts
Image 1: Lateral View of the Left Side of the Mouth and Face
Many insect mouthparts are unspecialised, used only for few tasks. The cockroach use their mouthparts to shovel food into the mouth crushed by strong mandibles, the wasp, more specialised, for chewing wood and masticating meat to feed young, but also for feeding on liquid. The butterfly has mouthparts modified into a long tube for sucking nectar. The bee has the highly specialised multifunctional mouthparts as described below.

The mouthparts of worker bees are used to manipulate wax, grab and pass pollen into the mouth, suck up liquid, dilute solid sweet substances, feed the queen, share food, and pipe food to individual larvae. When not in use the mouthparts are cunningly designed to fold backwards and then extended forwards into a double tube when required. The complex structures fold and are slung under the head by the cardines (singular cardo), one on each side, into the fossa of the proboscis.
The upper 'lip'or labium is suspended from the lorum. The small triangular V shaped sclerite located between the cardines is called the postmentum. Anterior to this is the elongated prementum. At the end of the prementum are the slender segmented labial palps. Between these arise the the glossa or tongue and on either side the paraglaossa.

The lower 'lip' is complex. The maxillae are composed of stipes, galeae, laciniae and the small possibly rudimentary maxillary palps.

When these are in use they are slung upwards and forwards by the cardines (singular cardo) to the mouth to be held firmly by the mandibles. The laciniae fit onto the epipharynx, creating that waterproof joint.

Thus in use the mouthparts are slung up to the mouth, the galeae and labial palps fit close together around the glossa forming an outer tube, the food canal. Suction created by muscles in the roof of the mouth suck liquids such as nectar and water up the food canal just like we do when using a straw. The glossa, a flexible rod, lying inside the food canal is deeply grooved forming an inner tube fringed by hairs, the salivary canal.
Starting with the mandibles or jaws. These are the strong 'biting' or manipulating parts. They also hold the sucking parts secure when in use. In the worker the mandibles are used to shovel pollen into the mouth, for manipulating wax when comb building or capping cells and collecting and using propolis. The drone has the smallest and hairiest mandibles. The queens' mandibles are toothed. The worker has workmanlike mandibles, spoon shaped with a groove directing secretions for when feeding larvae.

At the top of the mouth attached to the clypeus (the triangular plate at the front of the head) and between the mandibles is the labrum which has a soft pad on the underside, This pad helps make a waterproof seal when the sucking parts are in use.
Image 2 : Mandibles of A. Queen, B.Worker, C.Drone
Image 4 : Cross-section through mouth when used in sucking mode.
Image 5 : The Extended Tongue or Glossa