AGRISTARTUPS
AGRM-113
Lecture
Title
No.
2 Castes of Bees.
Dr. Nidhi Sharma
Assistant professor (Entomology)
MS Swaminathan School of Agriculture
Castes of bees
• The honeybee is a social insect and lives in
colonies with a highly organized system of
division of labour.
• Each hive consists of three castes: queen (fertile
female), drones (males) and workers (sterile
females).
• Each caste has its special function in the colony.
• Every honey bee colony comprises of 35000 to
70,000 members includes a queen, 200-300
drones and several thousand workers.
Egg
Fertilized Unfertilized
Light Heavy feeding+
Feeding Royal jelly Drone
Worker Queen
Queen
• The queen is a true mother bee. Queen is the
only female that is completely developed
sexually from fertilized egg.
• This is a result of a total diet of royal jelly
during the developmental period.
• She has a long abdomen extending well
beyond the apical margins of the wings.
• A well developed queen is generally two to
three times bigger than a worker and
measures about 15-20 mm in length.
Duties of a queen
1. The only individual which lays eggs in a colony
(Mother of all bees).
2. Lays upto 2000 eggs/day in Apis mellifera and
maintaining a populous colony.
3. Five to ten days after emergence, she mates with
drones in one or more nuptial flights.
4. When her spermatheca is filled with sperms, she will
start laying eggs and will not mate any more.
5. She lives for 3 years and when it is weak or unable to
lay eggs it is replaced by one of the daughter queen.
6. The secretion from mandibular gland of the queen is
called queen’s substance.
7. The queen substance if present in sufficient
quantity performs following functions:
a) Prevent swarming and absconding of
colonies.
b) Prevent development of ovary in workers.
c) Colony cohesion is maintained.
8. The queen can lay either fertilized or sterile
eggs depending on the requirement.
Drone
• Drones, the functional males of the colony are
produced from unfertilized eggs, and are larger
and darker than the worker.
• It is smaller than queen and measures about 15-
17 mm in length.
• The end of the abdomen is blunt and is covered
with a tuft of small hairs.
• Drones cannot sting.
• They also do not have any of the structures
necessary to collect nectar and pollen.
• It dies after successful mating with the queen.
Duties of a drone
• Their important duty is to fertilize the queen.
• They also help in maintenance of hive
temperature.
• They cannot collect nectar / pollen and they
do not possess a sting
Workers
• Workers are sexually sterile female caste and
is the smallest in size as compared with the
above two castes.
• On ventral side of the abdomen, wax glands
are present.
• Hind legs are modified for pollen collection.
• The mandibles are flattened and spoon
shaped which are used for molding the wax
for comb building.
Duties of a worker
• Their adult life span of around 6 weeks and
can be divided into:
1. First three weeks- house hold duty.
2. Rest of the life- out door duty.
House hold duty includes:
• Build comb with wax secretion from wax glands.
• Feed the young larvae with royal jelly secreted
from hypopharyngeal gland.
• Feed older larvae with bee-bread (pollen+
honey).
• Feeding and attending queen.
• Feeding drones.
• Cleaning, ventilating and cooling the hive.
• Guarding the hive.
• Evaporating nectar and storing honey.
Outdoor duty includes:
• Collecting nectar, pollen, propolis and water.
• Ripening honey in honey stomach.
Schedule of a worker bee in the hive
Days after
Task
emergence
1-2 Clean cells and warm the brood nest
3-5 Feed older larvae with honey and pollen
6-10 Feed younger larvae with products of the head
glands
11-18 Ripen nectar, produce wax and construct comb
19-21 Guard and ventilate the hive, take exercise and
orientation flights to learn to fly and locate the hive
22+ Forage for nectar, pollen, water or propolis
