Bees play an indispensable role in the ecosystem: approximately three-quarters of the world’s crops are dependent on bees for pollination in addition to other products such as honey, royal jelly, propolis, venom, bee wax, etc.
However, colonies have been collapsing due to disturbances in their habitats as a result of intensive agricultural practices, changes in land use, urbanization, and the use of pesticides harmful to a. Furthermore, bees are also threatened by extreme weather events caused by climate change. To save the bees, one needs to have scientific knowledge.
In India, Honeybees viz., Apis cerana indica (Indian bee), Apis mellifera (Italian bee), Apis dorsata (Rock bee), Apis florea (Little bee) and Tetragonula sps. (Stingless bee) have been observed pollinating various crops. Apis cerana indica (Indian bee or Satode muha mus) has been scientifically domesticated by Goan locals considering its role in pollination and honey production. However, Tetragonula sps. (konyatale muha mus) is being domesticated by few local Goans using indigenous technology inherited from their ancestors.
Bees are social insects live in a hive in where a queen bee lays eggs. The fertilized eggs produce females which may be young queen or workers (sterile female). Workers perform different functions in the colony, however drone only carries out of task of fertilization. A colony consists of a queen, few drones and maximum no of workers. The strength of the colony depends on the number of workers.
Bee Foraging and communication
Worker bees do most of the work in the hive. They start working early in the morning about 7-8 am and continue until till late evening. Depending upon sunshine & temperature they collect pollen, nectar, propolis and water.
Searcher/scout bee is the first to go out and finds the source of food. Later, they return to the hive to communicate to the rest of the bees. They communicate about the source by definite dancing pattern. When the source of food is close to the colony, the bee does the ‘Round dance’ (in circles clockwise and anticlockwise alternately every one or two circles). It does ‘Waggle dance’ in the pattern of making a straight run, then a semicircle back to the beginning of the straight line, moving up the top of the run and a semicircle in the opposite direction back to the beginning of the straight line again, which indicates the direction of the food source.
The quality of the source and the concentration is indicated by the intensity of the dance and this is how they go out in search of food. If the food source is very rich, the bees open up their scent/olfactory glands that are located on the 5th and 6th segment of the abdomen so that the bees searching for food in vicinity will know about it.
Even if there are two colonies placed very close to each other they will never take food from the same source because each colony has a unique and distinct odour. Bees fly at a speed of 25 to 30 kilometres per hour and usually foraging within a radius of 100 metres, but they can travel up to 1.5 kilometres. Favourable temperature for bee foraging is 25-27° C. Bees collect pollens from flowers. When a bee visits a flower, pollens from the flower are smeared on the bee’s body. The pollen comb present on the basitarsus cleans the body and collects the pollens in the pollen basket.
Flying bees can carry up to 35 percent of their body weight of pollen in one trip. The worker bee makes about 6000 trips a day to collect 500 to 1000 mg of pollen. Similarly, it makes about 19000 trips to collect nectar. Mouth parts are modified into a spoon like structure (flabellum). This allows the bee to lick the nectar from the base of flower.
Bee pasturage
Plants that yield pollen and nectar are collectively called as bee pasturage. They use nectar and pollen as raw materials for preparing their food. Nectar stimulates foraging for pollen and metabolizing stored honey and protein. Bee colonies require a large amount of pollen as a source of protein, vitamins and fats. Sorghum, coconut, sweet potato, roses, maize, tobacco, pomegranate and castor are pollen source plants while tamarind, glyricidia, moringa, pungam, neem, eucalyptus, soapnut tree are nectar source plants. Banana, berries, peach, safflower, citrus, pear, guava, apple, mango, plum, sunflower are both pollen and nectar source plants.
Crops pollinated by bees
Bees are instrumental in pollinating vegetables like okra, onion, beet, mustard, rapeseed, mustard, cauliflower, cabbage, broccoli, beans, carrot, squash, pumpkin, cucumber and gourds. Fruit/plantation crops include cashew, starfruit, strawberry, papaya, watermelon, orange, coconut, coffee, lemon, apple, mango, avocado, cherry, peach, pear, guava, tamarind, grape, hog plum (ambado) and pomegranate. Even spices like cardamom, allspice, chilli, paper and fennel are pollinated. Sesame, clover and sunflower are some of the oilseeds that are pollinated by bees.
It is said that there is “No Honey, No Money”. So, it is necessary to conserve the bees. On the World Bee Day, beekeepers and the farmers should take responsibility to save the bees to avoid the food shortage. Sweet Revolution in India also known as Honey Mission or Mithi Kranti has been launched to promote of the development of scientific beekeeping and production of honey and allied products to double the income of farmers. In the context of recent developments, the Khadi and Village Industries Commission (KVIC) has launched the country’s first mobile honey processing van in a village in Uttar Pradesh.
Bee keeping has vast potential in the state of Goa. Some talukas of Goa (Valpoi, sanguem, Quepem etc.,) fall in the Western Ghat and have diversified vegetation comprising of a variety of flowers blooming in different seasons. In Goa, naturally found Apis cerana indica, Indian bee (Satode muha mus yields about 2-5kg honey/year/colony) and Tetragonula sp., Stingless bee (koynatale/Poyeche mus) about 60-180 ml honey/year/colony). The honey is sold at Rs 1500-2000 per kilogram. The Goa College of Agriculture, Ela Farm, Old Goa has set up an Apiculture unit. This initiative aims to provide training to both farmers and students, with a dual focus on conversation of bee population in parallel to equipping farmers to generate additional income from honey and allied products.
(Rajan Shelke is the in-charge head, Assistant Professor, Entomology at Goa College of Agriculture, Ela Farm, Old Goa)