Honey Bee Behaviour
Honeybees are highly developed social insects. The importance of honeybees makes the man interested in its perpetuation. The behaviour in these social insects is guided by instinct. It is essential to acquire knowledge about their behaviour to make it possible for man to control and efficiently manage this valuable insect.
Division of Labour:
Worker bees of different ages perform different duties. During the first three daysafter emergence the worker bees remain busy in brood area where the nest temperature is 0 regulated to about 93 F. These bees are concerned with cleaning of cells. They start feeding honey and pollen to older larvae when they are about 4 days old. The food glands of worker bee develop and secrete “royal jelly” and she tends the younger larvae when 6-12 days old. There is again shift in duties at the age of 14 days when bees wax glands become active. She secretes wax for comb building and do any other duty in the hive. The worker bees become field foragers at about the age of 21 days after emergence. This division of labour is not a rule and there can be a change in the schedule, depending upon the needs in the hive. Worker bees start taking orientation flight during second week of their emergence. These play flights are meant to acquaint themselves with vicinity of the hive and scope of the play flights increases with age.
Communication and Memory:
Field bees search the pollen and nectar sources and bring a load to hive. Distance and direction of the source is communication to fellow foragers by means of peculiar dances which are performed in relation to the position of the sun. The riches of the source is communicated by the liveliness of the dance. Other bees then go in the direction and search for the source with scent perceived from the pollen or nectar load of the dancer. They have the capability to calculate the position of the sun without seeing it. Field bees memorize the location of the source at the particular time of the day, depending upon the pollen or nectar presentation by the flowers. The bees continue to visit the source till some better source is found out.
Communication in Bees
Sir Karl Von Frisch (1967) : Professor of Zoology at the University of Munich in Germany Book “The Dance Language and Orientation of Bees” Cambridge Press, USA. He was awarded the Nobel Prize in Physiology or Medicine in 1973 for his discoveries. Honeybees perform 2 type of dances on their return to the hive, known as round dance and waggle dance. Round dance : When a food source is very close to the hive (less than 50 meters), a forager performs a round dance
The Waggle dance or wag-tail dance
Performed by bees foraging at food sources thatare more than 100 meters from the hive. This dance communicates both distance anddirection. A bee that performs a waggle dance runs straight ahead for a short distance,returns in a semicircle to the starting point, runs again through the straight course, then makes a semicircle in the opposite direction to complete a full figure-eight circuit. While running the straight-line course of the dance, the bee's body, especially the abdomen, wags vigorously from side to side. This vibration of the body produces a tail-wagging motion. At the same time, the bee emits a buzzing sound, produced by wing beats at a low audio frequency of 250 to 300 hertz or cycles per second.
Control of Reproduction
In the honeybee colony worker bees have undeveloped reproductive system and queen isthe single developed female. Queen's mandibular gland secretion is dispersed over whole of her body. The workers lick this queen or diminish under overcrowded conditions during swarming. Under these circumstances there is initiation of queen cell building by workersand the development of ovaries of the workers. The laying workers may appear in the colony if the colony does not succeed in replacing the queen. The eggs laid by such workersproduce drones.
Field Activities
Foraging activity provides raw materials for the hive. The materials collected are nectar, pollen, water and propolis.
Nectar
Nectar is a sweet-surgery secretion of the nectaries of flowers and other parts of the plant. The nectar is sucked up and stored in honey stomach. After reaching the hive the forager unloads herself by distributing the load to hive bees. Hive bees ripen the nectar. During the process there is enzymatic conversion of sugers and moisture is reduced. These hive bees than seek out cells and deposit the drop of unripe honey. Nectar load is 15-30 mgs in Indian bees (varies with race) and 30-40 mgs in mellifera. Each day 10-20 loads may be brought in by a forager visiting 50-500 flower for each load.
Pollen
Pollen is important for brood earing, since it is a protein source. A load of pollen varies from about 20 kgs and each load is collected from 50 to 200 flowers. A load is collected in 10-20 minutes and as many as 45 loads can be collected each day by a forager.
Water
Water is required in the hive for dilution of honey for larval food when there is no nectar income. Water is also needed to requlate nest humidity and for cooling down hive temperature through evaporation by fanning the bees. Water foragers complete a trip in about 5 minutes and have average of 50 trips per day.
Propolis
It is a sticky resinous material. Propolis is used to stick down frames, forproofing the walls of hive and cover unwanted debris which cannot be pulled out by bees.Indian honeybee does not collect propolis but mellifera bees are heavy propolisers
Temperature Control
Bees cannot regulate their body temperature individually but can regulate colony 0 temperature. When atmospheric temperature drops below 57 F bees form a cluster and the compactness of the cluster increases with the decrease in temperature. The heat produced by the muscular movements by bees is conserved by the cluster.
Brood Cycle
Bees cluster below 57 F and remain inactive in cooler regions where the wintertemperatures are low and no flora is available. Brood rearing is stopped, but in most partsof India the winters are milder and flora from oilseed crops is available. In such areas thebees do forage but the working hours restricted to 4-5 hours. Brood rearing is there and colonies grow in strength. Brood rearing starts or increases two weeks before spring flowers appear. Pollen and nectar are eagerly gathered. Large quantities of water are also collected for elaboration of food. New bees emerge and they can now cover larger comb areas, thus the brood rearing is rapidly expanded. The brood nest becomes crowded in late spring and the colony prepares for swarming. New queens are reared and the old queen leaves with “prime swarm”. Secondary swarms may be issued later on. Swarming instinct is more prominent in Indian hive bee as compared to mellifera. Nectar which remains unused is stored as surplus during early summer in the form of honey. Pollen is stored as bee breed. Because of high summer temperatures and lack of flora, the brood rearing is stopped. Colony strength depletes. The drones are deprived of food and driven out to die. During later part of monsoon season some subsistence flora becomes available to bees and some brood rearing is resumed which picks up with flowering of Brassica Crops.