Figure 1: Honey-bees in a Beehive

“If the bee disappeared off the surface of the globe, then man would have only four years of life left. No more bees, no more pollination, no more plants, no more animals, no more man.”

-Albert Einstein

Ever been curious about the fascinating “flying-buzzing machines”, that are silent yet prominent players of mother nature? Despite being a tiny insect, Bees, this marvellous creation of nature aid in pollination, honey and bee-wax production, agriculture, biodiversity and genetic diversity conservation, etc., such that, irrespective of how they may appear to be scary, a world without this highly diverse group of insects will be more terrifying. Although these insects boast globally wide-spread distribution, these resilient creatures are being severely threatened by both natural and anthropogenic processes, including urbanisation, industrialisation, pesticides, climate change, etc., irrespective of their tremendous contribution to humanity and mother nature. Therefore, as World Bee Day unfolds on March 20, 2024, let’s explore the amazing lives of bees and find ways to contribute to their conservation as global citizens.

The Bees: Architects in the Nature

Generally, any insect species out of 20,000+ species that belongs to the monophyletic lineage, superfamily Apoidea is considered under the common term “Bees”. According to taxonomic classification, the bees belong to the Domain Eukarya, kingdom Animalia, phylum Arthropoda, class Insecta, order Hymenoptera, suborder Apocrita, superfamily Apoidea, and the clade Anthophila. Along with being close relatives to other insect species such as ants and wasps, the bees are categorized under seven families: Andrenidae, Apidae, Colletidae, Halictidae, Megachillidae, Melittidae, and Strenotritidae. Some of the common bee species include Honey bees (Apis sp.), Bumble bees, stingless bees, sweat bees, carpenter bees, leafcutter bees, etc. This diverse group of organisms are widespread over all continents except Antarctica, with more abundance in the non-tropical regions, as a shred of evidence for their co-evolution with the flowering plants.

Figure 2: Global Distribution of Bees

Being a tropical country, Sri Lanka also hosts a high abundance and remarkable diversity of bees, most importantly, honey bees. The Sri Lankan bee population consists commonly of four families: Apidae, Colletidae, Helictidae, and Megachilidae, comprising 38 genera and 149 species, according to current literature. All the honey bees in Sri Lanka belong to the family Apidae, including the species Asian Hive Honey-bee (Apis cerana) (the most common), Giant Honey-bee (Apis dorsata), Dwarf Honey-bee (Apis florea), and Dammar-bees (Trigona iridipennis).

The Bee Body: The External Anatomical Wonders

One should not be fooled by the small size of the mighty bees. Irrespective of their smaller body size, bees possess complex structural diversity and highly adapted structures to suit their ecological function. Bees share the same basic body structure as other insects, with three segments: the head, thorax, and abdomen. The head mainly comprises two large compound eyes, along with three small eyes, “ocelli,” a pair of antennae with 12 or 13 segments (depending on whether they are male or female, respectively), mouthparts including a pair of mandibles, and a proboscis. The thorax is separated into three segments, with each segment bearing a pair of legs, and a pair of wings, each in the hind two segments. The abdomen consists of 9 segments, and the hindmost segment is modified into a stinging apparatus. The stinger differs between the queen, the worker, and the drone. Generally, an adult bee has a size of 2 mm to 4 cm, on average.

Figure 3: Basic external body plan of a bee.

Hive of Activity: Behaviour, Diet and the Social Structure

Apart from the structural complexity, bees boast remarkable behavioural complexity as well. Even though it is well-known for its organized social structures, 75% of the bees are solitary. These solitary bees tend to live and raise their offspring alone, whereas the female bee herself builds their nests in the ground or dead wood, lays eggs, and gathers nectar and pollen for the new offspring. Moreover, 15% of the bees are brood parasites, where the female cuckoo bees enter the host nest, and lay eggs and leaves, whereas the newly hatched offspring of the cuckoo bee feed upon the host’s offspring and depend upon the host offspring’s diet. Among the other bees, 9% of them are considered social bees. In the same nest, many bees tend to live together, and as a result, all female bees have their own distinct role to play. These can be further classified as highly social bees (that live in larger colonies, and the queen is solely responsible for reproduction, and cannot survive without the rest of the working bees). Primitively social bees (the bumble bees and some sweat bees tend to live in small colonies with division of labour, and new colonies start with a single female, where until the emergence of the first brood, there will be no colony life). Moreover, only 0.5% of the bees account for social parasites. Moreover, another noticeable feature in a bee community is the division of labour, such that the females perform a wide range of services, including building nests, stinging, and gathering food, whereas the males are responsible for breeding. The male bees tend to be aggressive towards each other for mates and possess various tactics in attracting mates for reproduction.

When bees are concerned, must come the topic of their “waggle dance”! The communication system in bees possesses a well-studied series of “dances”, for the communication of the presence and directions of food sources, including the famous “Waggle Dance” and the Round Dance. These dances include factors such as the distance and the direction of the food source. The Round Dance is performed for food sources relatively closer (25–100 miles away), where the bee runs in a circle, often switching directions, after distributing nectar with the waiting bees. However, Round Dance provides no directional information. Bees switch to a Waggle Dance when the food source is distantly located, and this dance includes both the distance and the direction to the food source from the hive.

Figure 4: The Round and Waggle Dances of the Honey Bees

The diet of the Bees, especially the honey bees, comprises nectar and protein-rich pollen, which are generally collected during foraging, further facilitating pollination. This process is carried out by the use of the proboscis, and the hair-like structures that facilitate the adherence of pollens into the body. Moreover, reportedly between 20-45% of wild bees are pollen specialists.

Beehive is a cradle of social structure, with an excellent example of nature’s social hierarchy and labour distribution. The adult bees in the hive can be categorized into three groups: workers, drones, and the queen, each with distinct tasks to carry on.  Each colony hosts a single queen, who is the only sexually developed female and solely responsible for mating and laying eggs during the season. Moreover, the queen can release pheromones to keep the entire colony glued together. The male bees: “the drones” are the largest in the colony, with their main function being fertilizing the queen. They generally tend to depend on worker bees for food. The “workers”, the sexually under-developed females which constitute the majority of the colony mainly act as foragers in the hive and fulfil other tasks including cleaning and polishing the cells, feeding the brood, caring for the queen, removing debris, handling incoming nectar, building beeswax combs, guarding the entrance, and air-conditioning and ventilating the hive.

Figure 5: Comparison of the queen, a worker and a drone bee

Tiny but Mighty: Services of the Bees

Undoubtedly the bees are a marvellous creation of Mother Nature. Irrespective of its small body size, the bee carries out a series of services to both humans and the environment, ranging from well-known functions such as honey and bee wax production, and pollination to large-scale services including providing ecosystem services, and biodiversity and genetic diversity maintenance and conservation.

  • Pollination: Bees can be considered as the key pollinators of flowering plants. Nearly 90% of the world’s flowering plants depend entirely or partially on some kind of pollinators, and nearly 75% of the global food crops and 35% of the global agricultural lands too. Among other possible pollinators including vertebrates, birds and other insects, bees play a major and crucial role in pollination, one of the most essential natural processes in fruit production in flowering plants.
  • Crop-production: As depicted above, at least 75% of the world’s crop products are produced with the aid of pollinators, in which the majority is represented by bees. Therefore, with the growing population, the role of bees in the pollination of vegetables, fruits, etc. is much more important than ever.
  • Honey and bee-wax production: Bees are hailed as nature’s alchemists for their ability to produce honey and other compounds from collected nectar and pollen in the bee hives. Honey processes its downstream applications as a food sweetener, an ingredient mostly used in indigenous medicine, and heavily used in the food industry. Bee wax, extracted from bee hives is used in various industrial applications including pharmaceutical applications, cosmetic industry, and other wax-related applications.
  • Biodiversity and Genetic Diversity conservation: Bees showcase co-evolution with flowering plants, playing a key role not only in their evolution but also in their existence, by aiding the completion of the life cycles of plants. Therefore, it contributes to the maintenance and conservation of both flora and fauna, thus providing large scale of ecological-services. Moreover, cross-pollination plays a key role in maintaining a considerable level of genetic diversity in a flowering plant species, to minimize inbreeding depression.

A Red Light to the Guardians: The Threats towards Bees

However, irrespective of their importance in an ecosystem, challenges against these Guardians are never scarce! Both anthropogenic processes and resulting natural circumstances have started to challenge the survival and well-being of these fascinating creatures, thus adversely affecting the balance of the environment. Some key challenges can be categorized as:  

  • Air pollutants and pesticides are a key threat towards the survival of the bees. The air pollutants are capable of blocking the sensing process of the scent molecules released by plants, thus increasing the difficulty in locating flowers, prolonging the pollination process, and reducing its efficiency. Pesticides can also reach the bees through soil, air, and water, whereas neonicotinoids can impact the reproductive success of these pollinators, such as bees. Moreover, pesticides can affect the navigating patterns, learning and breeding of bees, and neurotoxic compounds in pesticides can negatively affect their ability to recognize their nests.
  • Lack of vegetation cover and deforestation are another key challenges towards Bees, mainly led by industrialization and urbanization. The lack of vegetation has led to a decrease in the availability of food and shelter, resulting in a decrease in global bee population. Moreover, lack of vegetation can lead to increasing predator pressure, further leading to decreased bee numbers in the world.
  • Invasive species (both fauna and flora) are another problem faced by bee populations around the world. Especially, in wild bees showcasing host-specificity, the advent of invasive flora can have detrimental impacts. Other than that other invasive fauna can also cause increased competition, increased predation, etc. thus reducing the bee numbers around the world.
  • Climate change and global warming can also detrimentally affect the survival of the bees, by interrupting their general behavioural patterns.

Hail Golden Harvesters: Steps towards Conservation

The quote “They may look scary, but a world without bees will be scarier.” is enough to convince the magnitude of the crisis that may arise in a world with a small bee population. Due to the detrimental impacts associated with the depletion of the bee population, numerous global and local actions were taken to address the above issue. Being one of the biggest threats to bees, the use of pesticides is being tightly regulated through strict rules and regulations around the world. Especially in 2018, the European Union has partially banned neonicotinoid-containing pesticides due to their well-known lethal effects on bees and adverse effects on pollination as a whole. Other than that, sustainable farming practices, promotion of bee-keeping even at the household level, and habitat restoration to promote the availability of host plants, etc. are being encouraged to be practised to sustain the bee population. Both governmental and other organizations are concerned about the betterment of these golden harvesters for a golden future, and conduct many awareness programs to promote the protection and bee-keeping projects around the world. As a result, the United Nations has reserved 20th May 2024 as the World Bee Day, to further strengthen the above conservation efforts.

Sri Lanka, being a tropical country with rich bee diversity, has already taken fore-steps for the conservation and promotion of the Bees. There, many research studies have been conducted to explore the diversity of the bee population in Sri Lanka, and the Department of Agriculture has pioneered many programs for the promotion of bee-keeping at both industrial and rural levels. Further steps have to be reinforced for the betterment of these Golden Harvesters in Sri Lanka, at both governmental and individual levels.

A Day for Buzzing: The World Bee Day

A day for the Bees! In 2018, the United Nations declared 20th May as World Bee Day, to raise awareness of the importance of pollinators, the threats they face and their contribution to sustainable development. There, it is aimed at protecting the bees and the other pollinators so that their contribution can be used for a significant impact on eliminating world hunger. Every year, the UN and other organizations host many awareness and promotional programs to promote the protection measures for Bees. This year, World Bee Day is hosted under the theme “Bee Engaged with Youth”, emphasizing the importance of the involvement of the youth in bee-keeping practices and improving their understanding of the importance of bees in our future stewards of the environment. There, it is aimed to raise the awareness among youth and other stakeholders, about the essential role of bees and other pollinators in agriculture, ecological balance, and biodiversity preservation, thus it can inspire a new generation of environmental leaders to make a positive impact on the world.

Figure 6: A Flyer designed for World Bee Day 2024

Therefore, as global citizens, on this special day, let’s take a moment to appreciate the Golden Harvesters buzzing around, and take the initiative to step to protect these “tiny buzzing friends” for future generations!

Written by:

P.K.D. Chathumini Yasara

4th Year Undergraduate

Immunology and Integrative Molecular Biology

Faculty of Science,

University of Colombo.


Image Courtesy:


Leave a Reply

Avatar placeholder

Your email address will not be published. Required fields are marked *