honey bee glands

different types of glands in honey bee and their functions

1. Topic : Honey Bee Glands Family : Apidae Order: Hymenoptera seven members of the  genus   Apis Apis cerana indica is the indian honey bee It’s estimated that out of 90% of the world’s food, bees pollinate 70%

2. Glands of honey bee worker DGld - Dufour's gland HGld - head salivary glands HfGld - hypopharyngeal glands KGld - Koschevnikov glands MdGld - mandibular glands NGld - Nasonov gland ThGld - thoracic salivary glands VGld - venom gland WxGld - wax glands

3. honey bee drones Drone mandibular glands are much smaller than those of queens and workers and their size varies according to age. The secretory activity increases from 0–3 days old to a maximum at 7 days of age, while after 9 days the glands were no longer active..

4. Glands of honey bee queen Dgld - Dufour's gland KGld - Koschevnikov glands MdGld - mandibular glands TGld - tergal glands* VGld - venom gland

5. Dufour's gland Dufour's gland (also called alkaline gland) occurs only in females (queens and workers) and it is absent in drones. It is an unpaired and unbranched epithelial sac consists of a single layer of epithelial cells, which luminal surface is covered by cuticle. At the surface of the gland there are muscles which can be used to discharge the gland's secretion.  

6. Size of the Dufour's gland differs between queens and workers . The gland length increases after start of egg lying by the queen.  Secretion of the Dufour's gland contains hydrocarbons and esters. Queens produce much more of the secretion than workers Composition of the secretion can change after insemination or onset of oviposition by the queen.  the Dufour gland secretes compounds that are utilized in defence by workers or reproduction in queens The Dufour's gland secretion is attractive to workers and can be responsible for retinue formation around queens  

7. Dufour's gland is homologous with colleterial glands of other insects. During development it is formed as invagination of the ninth sternum . It is the egg marking pheromone It allows to discriminate between eggs of the queen and those of the egg laying workers. The gland occurs in most Apocrita but its secretion and function differs between species. In species other than honey bee it can produce building material, larval food or pheromones 

8. Hypopharyngeal glands Hypopharyngeal glands consist of a pair of long glands coiled in the sides of the head. Each gland consists about 550 oval  acini  attached to an axial collecting duct  . It is covered inside with cuticle. The ducts open on the suboral plate of hypopharynx The glands are most active in young bees, however, they can be also developed in old workers if young workers are absent, for example in queenless colony .

9. The hypopharyngeal glands are active only in workers which have direct contact with brood  . Secretion of the hypopharyngeal glands is rich in proteins. The secretion of young workers is important component of royal jelly  . The secretion of older workers contains sucrose hydrolysis enzymes  including alpha- glucosidase , amylase, and glucose oxidase   . Activity of the glands depends on age of workers their food and presence of larvae .

10. Workers with developed hypopharyngeal glands consume more pollen  . Hypopharyngeal glands are less developed in workers starved, injected with juvenile hormone  , poisoned with pesticides, carbon dioxide  and other anaesthetics

11. Mandibular glands Mandibular glands consist of a pair of saclike glands . Each of the glands is located inside head above the base of mandible. The gland opens through a short duct at the base of the mandible. Its secretion runs along shallow groove into deeper channel surrounded by hairs . very large in queens, relatively large in workers and small in drones . In workers secretion of the gland changes with age 

12. Nasonov gland The Nasonov gland is exposed by : workers forming swarm cluster , young workers returning from orientation flight , foragers at a food source, returning foragers when they have problem with finding the nest entrance Nasonov pheremone helps to orient   the forager bees. They release them on flowers so other bees know to which flowers have nectars.

13. Nasanov gland occurs only in workers, not in queens or drones. Composition of the secretion changes with age of workers  and differs between winter and spring  Synthetic Nasonov pheromone can be used to attract swarms to swarm traps attract bees to crops for pollination Associated wih tergum

14. The salivary gland system comprises two pairs of exocrine glands, one in the head (head salivary glands) and one in the thorax (thoracic salivary gland). The glands are connected by common salivary duct to salivary pocket ( salivarium ) at the base of labium. The head and thoracic glands differ in protein expression  . Salivary glands are well developed in queens and workers; in drones they are small.   Salivary glands of workers are more active when they are foraging  . salivary gland system

15. HGld - head salivary gland Res - reservoir of thoracic salivary gland slDct - common salivary duct ThGld - thoracic salivary gland

16. Head salivary glands of queens become more active when they start egg laying . In drones head salivary glands degenerate when they become sexually mature . Head salivary glands produce oily secretion which contains mixture of hydrocarbons  . It was suggested that it is used to: soften wax  and lubricate mouthparts  The head salivary glands can be a source of cuticular hydrocarbons. The secretion can be added to royal jelly 

17. Venom gland Venom gland and venom sack (called also poison gland and poison sack) of honey bee worker.

18.  The venom gland consists of a pair of long, slender, convoluted tubules which float freely within the hemolymph of the posterior part of the abdomen . Secretory cells occur along the length of the tubules, their small ducts opening into a common, chitin-lined duct. Each tubule ends with a small glandular enlargement, and the two tubules unite in a short common duct. The duct opens into the anterior end of the venom sac The stinging apparatus is a modified ovipositor.

19. The venom injected into the victim when a worker stings is a mixture of toxic proteins and peptides, the major component being a protein called melittin (toxic) . Venom contains other compounds such as Apimin : toxic peptide that damages nerve cells hyaluronidase , phospholipase , acid phosphatase and histamine

20. The poison sac walls have no muscles, and the venom therefore is not expelled by contraction of the sac; it is driven through the canal of the sting by the action of the sting lancets and their valves  The venom gland is present in both the worker and the queen castes, but queens have significantly larger glands than the workers and produce more venom. Queens use venom during fights with other rival queens, an event that occurs as soon as the imago (mature adult stage) emerges, while fertilized queens rarely use venom. by the time queens are one to two years of age their venom has become essentially inactive . Queen venom is more lethal toward other honey bees than is worker venom.

21. Wax glands are located on sternites 4, 5, 6 and 7. They consist of modified epidermal cells . The cells are larger when the gland is active.   The wax is secreted as liquid and it hardens forming a wax scale. The wax scale is moved by hind leg to mandibles.   Production of 1 kg of wax requires consumption 8.4 kg of honey. The wax glands are active only in workers who were fed with pollen during first 5-6 days of their life  Wax glands

22. Koschenikov’s gland Located dorsally near the string shaft. Produces alarm pheromone Contains more than 40 different compounds. Released by queen bee for the cluster of workers around it Also released when a honey bee stings an animal to attract other honey bees to attack as well

23. references http://honeybee.drawwing.org/book/wax-glands Wikipedia

24. Thank you Presented by: Naincy Sharma Id no . 2017002056