Addressing Nutritional Gaps in Honey Bee Colonies: Synthesis of Existing Studies and Implications for Beekeeping Sustainability in West Bengal, India

INTRODUCTION

Beekeeping, an age-old practice integral to sustainable agriculture and rural livelihoods, has immense potential beyond honey production, yet remains underutilized in many parts of India, including West Bengal. Beekeeping, or apiculture, with Apis mellifera and A. cerana, is often featured in conversations about sustainable development and livelihood enhancement in India (Abrol, 2023; Basu and Purkait, 2023); however, in practice, most initiatives continue to focus predominantly on honey production. Despite various governmental efforts to support the sector (Narang et al., 2022), the industry remains predominantly focused on honey as the primary source of income for beekeepers. This narrow focus often results in the neglect of other valuable hive products such as bee pollen, royal jelly, propolis, and bee venom, which hold significant potential for economic diversification and increased revenue (Ghosh et al., 2021a). Recent proposals have emphasized the nutritional potential of honey bee brood, particularly drone brood, as a source of food and animal feed due to its rich nutritional profile (Ghosh et al., 2021b). However, despite being a leading producer of honey globally, the Indian beekeeping industry still faces concerns regarding quality (CSE, 2020) and falls behind its counterparts in industrialized nations, where the diversification of hive products significantly contributes to sector growth and resilience. This over-reliance on honey limits the overall expansion and economic viability of apiculture in India, including in regions such as West Bengal.

BEE-FLORA OF WEST BENGAL

As highlighted by Narang et al. (2022), the availability of diverse bee flora throughout the year, albeit with seasonal variation, serves as a significant advantage or strength for beekeeping. Similarly, the favourable environment of West Bengal offers a range of floral diversity crucial for the nourishment of bees. West Bengal’s diverse geographical landscape, from the Himalayan foothills in the north to the southern coastal regions, creates significant variations in climate that impact plant and crop blooming times across its districts. In the cooler northern districts like Darjeeling and Kalimpong, a temperate climate promotes early blooming of tea plants and flowering of orchids like Dendrobium due to consistent mist and cooler temperatures (Fig. 1). In contrast, the central and western districts such as Purulia, Bankura, and Birbhum experience a drier, hotter climate with marked seasonal shifts, where mango trees bloom later compared to northern areas, and crops like mustard are timed to match the arid conditions. The humid subtropical climate of eastern districts like Nadia and Murshidabad encourages earlier blooming of Boro rice and litchi trees in spring, benefitting from high temperatures and ample rainfall. Meanwhile, the southern coastal districts, including South 24 Pargonas and East Midnapore, have a tropical climate influenced by the monsoon, fostering early flowering of mangrove trees like Sundari and year-round cultivation of crops like coconut and betel leaf due to persistent moisture. This diverse range of climatic conditions showcases the unique agricultural practices needed for different parts of West Bengal to thrive.

Fig. 1.

Study area - (A) The location of state of West Bengal in India; (B) Districts of West Bengal and key bee-flora especially for beekeeping of the state; (C) Photographs of some of the bee-flora of the districts [Map outlines and photographs were sourced from web].

1. Diversity of bee-flora

Nectar and pollen are essential nutritional sources for honey bees. Nectar, primarily providing carbohydrates, is collected from plants known as nectariferous plants. Pollen, on the other hand, is a source of protein (including essential amino acids), fats (including essential fatty acids), and micronutrients (vitamins, and minerals). Plants that provide pollen are referred to as polleniferous plants. Identifying the botanical sources that nourish honey bees can be done by analysing honey (to find out nectar source) to extract and identify pollen or by using pollen traps to collect bee-foraged pollen (to find out pollen source) directly for identification.

Mukhopadhyay et al. (2007) conducted an analysis of honey samples (from A. cerana indica and Apis florea) collected during summer, autumn, and winter from rural areas of Darjeeling and Jalpaiguri districts. They aimed to identify the botanical origins of nectar sources. The study revealed 165 pollen taxa across 73 plant families. Notably, 18 of 50 studied unifloral honey samples were dominated by pollens from Rosa sp., Ageratum conyzoides, Rubus ellipticus, Prunus sp., Millettia pulchra, Trifolium repens, Primula sp., Schima wallichii, Fragaria sp., and Potentilla sp. in summer; A. conyzoides, S. wallichii, Sedum multicaule in autumn; and Aristolochia sp., Rosa sp. in winter. Basak et al. (2025) analyzed honey of A. cerana to identify the major and minor nectar sources in the Sub-Himalayan region of West Bengal, focusing on areas such as Kolakham, Buxa, and Jayanti, and compiled a month-wise nectar calendar. Among the major nectar sources, Mimosa pudica served as a key nectar source from January to March. In March, Imperata cylindrica and Syzygium cumini were significant, while Erigeron karvinskianus dominated from April to September. Other major sources included Prunus persica in April, Pavetta indica in May, Tectona grandis, Mimosa rubicaulis, and Saccharum spp. from June to October, Cestrum aurantiacum from June to December, Macaranga indica in August and September, Dicliptera bupleuroides in September and October, and Clematis buchananiana from October to December (Basak et al., 2025). Additionally, minor bee-flora in the region included Borassus flabellifer, Meyna spinosa, Eucalyptus globulus, Combretum decandrum, Grewia optiva, Albizia lebbeck, and Fuchsia magellanica, among others (Basak et al., 2025).

Layek et al. (2020a) investigated A. mellifera pollen foraging across four different places in districts in southern West Bengal (Nadia, Burdwan, Bankura, and Paschim Midnapore). They found significant seasonal variations in pollen taxa, with the highest collection in winter and spring and the lowest during the monsoon (a dearth period). Key biomass-contributing plants included Brassica nigra, Eucalyptus globulus, Borassus flabellifer, Sesamum indicum, Acacia auriculiformis, Coriandrum sativum, Cocos nucifera, Phoenix sylvestris, and Mikania scandens. Mondal et al. (2023) reported major pollen sources for A. cerana in Paschim Medinipur, including Acacia auriculiformis, Brassica juncea (brown mustard), C. nucifera, Eucalyptus sp., Neolamarckia cadamba, Peltophorum pterocarpum, Sesamum indicum, and Tridax procumbens. Pal and Karmakar (2013) documented that the forage spectrum of A. mellifera in Gangetic West Bengal encompasses a total of 77 species of flowering plants, and they developed a month-by-month floral calendar. Key pollen sources among these include C. nucifera, P. sylvestris, B. flabellifer, Citrus maxima, Carica papaya, Pongamia pinnata, Luffa acutangula, Croton bonplandianus, Terminalia arjuna, Bauhinia malabarica, Averrhoa carambola, Chrozophora rottleri, Monochoria hastate, Anthocephalus cadamba, A. auriculiformis, Murraya paniculata, Cleome viscosa, E. globulus, and Xanthium strumarium. Notable nectar sources include B. nigra, Moringa oleifera, B. flabellifer, Syzygium cumini, S. indicum, A. cadamba, Impatiens balsamina, E. globulus, A. auriculiformis, and M. scandens. Das et al. (2024) studied the pollen foraging pattern of A. mellifera, A. cerana, and Tetragonula bengalensis in the lower Gangetic alluvium of West Bengal during dearth period. Predominant pollen sources included Commelina diffusa, Aeschynomene aspera, C. nucifera, and E. globulus, with clear evidence of resource partitioning among the species.

An investigation into the botanical origin of winter honey from Howrah district revealed that pollen grains from B. nigra, C. sativum, and C. nucifera were predominant in most honey samples, indicating their source in the region’s winter crops and plantations. Additionally, pollen from some anemophilous plants, particularly those belonging to Poaceae and Cyperaceae families, were noted as significant minor contributors. The analysis also identified pollen from various weeds such as C. bonplandianus, Leucas sp. and Parthenium hysterophorus as minor components within the honey samples, alongside the pollen from economically valuable and cultivated plants (Chakraborty et al., 2023).

Kamble et al. (2015) conducted melittopalynological analyses of honey samples from the Sundarbans mangrove region of West Bengal. Their study of A. mellifera honey identified six unifloral and three multifloral samples. Ceriops decandra was the predominant pollen type in five samples, while Aegiceras corniculatum dominated one. Secondary pollen sources included Bruguiera gymnorrhiza, Sonneratia apetala, and Bunium persicum. Overall, 37 plant species were recognized as forage sources. For Apis dorsata, C. decandra appeared as the predominant pollen in two samples and secondary in one, while Kandelia candel was present in all A. dorsata samples as a secondary source but absent in A. mellifera, suggesting resource partitioning between these species.

Table 1 presents information on the bee flora of West Bengal, derived from studies on honey and bee-pollen. While these findings have been primarily obtained through investigative and microscopic analyses, it is important to note that there is potential for numerous other floral resources from bees yet to be explored. Layek et al. (2020b) highlighted that honey collection methods impact the pollen composition detected, affecting the determination of true nectar-foraging plants. Their findings showed that extracted and squeezed honey had significantly more pollen grains compared to pipetted honey. Pollen from nectar-deficient but polleniferous plants, such as Capparis zeylanica, Echinochloa frumentacea, Papaver somniferum, Poaceae type, Nelumbo nucifera, Solanum melongena, and Solanum sisymbriifolium were present in extracted and squeezed honey samples. Employing molecular techniques for plant identification could help uncover these resources (Sun et al., 2024).

Table 1.

Information on the bee-flora of West Bengal, derived from scientific studies on honey and bee-pollen

2. Seasonal nectar and honey production

Table 2 provides an overview of the key or important plant species that serve as nectar and pollen sources for managed honey bees, detailing their scientific names, vernacular names, and blooming seasons, based on existing studies and the author’s experience.

Table 2.

Floral calendar of important bee-flora for beekeeping in West Bengal, India

Mustard serves as a principal nectar source for honey bees during the winter months, yielding an abundant nectar flow that supports robust honey production (Personal communication, SG). Das et al. (2023) presented an in-depth overview of the frequency of honey harvests and the yield from target crops during migratory periods. Beekeepers typically harvest mustard honey at intervals of 8-10 days during the season, with an impressive yield ranging from 15 to 18 kg per hive. Eucalyptus, another significant source of nectar, sustains honey production with harvests occurring at approximately 15-day intervals. Each hive can produce an average of 15 to 17 kg of honey during this period, contributing to a substantial part of the seasonal yield. Litchi blossoms are notable for their rich nectar, which imparts a distinctive flavor to the honey. The litchi season usually allows for harvesting every 8-10 days, with average yields of 4-6 kg per hive.

This type of honey is particularly valued for its unique taste profile. Sundarbans honey, a multifloral variety, is often esteemed as pure honey by consumers, primarily due to its origin in forested regions free from pesticide exposure. Hives placed deep within the forest can produce as much as 40-45 kg of honey per box, whereas those situated near populated areas yield approximately 10-12 kg per hive. The harvest cycle for Sundarbans honey is generally every 10-12 days. Sesame, known locally as til, also provides an ample nectar source. Beekeepers typically harvest honey from sesame blossoms every 10-12 days, yielding about 5-6 kg per hive. Coriander and black cumin are additional nectar sources for bees, though their honey yields are lower, producing about 2-3 kg per hive with harvests spaced 15 days apart (Das et al., 2023 and Personal communications of SG with beekeepers).

According to personal communications with beekeepers, it is common practice to expedite harvesting before the optimal period. This practice can shorten the interval between harvests, often preventing sufficient evaporation of moisture from the honey and leading to higher moisture content. This, coupled with the naturally high humidity in the area, contributes to elevated moisture levels in the harvested honey.

Nectar and pollen from Moringa (drumstick) trees play a vital role in bolstering colony strength, while consistent high nectar flows from mango, jamun (black plum), and other fruit trees are crucial for colony build-up in spring. By April, when many other floral sources diminish, wildflowers such as neem and jujube, as well as crops like sunflower, become key nectar and pollen providers, sustaining bee populations in early summer. Late summer sees the emergence of karanj as a nectar source. During the monsoon, coconut blossoms supply nourishment, and guava trees provide moderate amounts of nectar and pollen, which aid in maintaining colony popula tions as the dearth season begins - a period marked by limited food resources for bees. Although the tropical climate supports a wide range of flora, plants such as amla, acacia, paddy, maize, pumpkin, cucumber, and various seasonal vegetables offer supplementary nectar and pollen.

3. Migratory beekeeping practices

Due to the honey-centric nature of apiculture, a significant portion of beekeeping in West Bengal involves migratory practices. Beekeepers move their colonies to follow regions with high nectar-yielding crops to optimize honey production. Previous studies identified several migratory routes utilized by beekeepers across the state (Purkait and Basu, 2022; Das et al., 2023) as represented in Table 3. Typically, the migration period begins around October or November and continues until May or June, depending on the routes and nectar sources available.

Table 3.

Important floral resource of migratory beekeeping following different routes of migration in West Bengal, India

Beekeepers strategically target specific crops known for their abundant nectar production. Commonly pursued crops include eucalyptus, mustard, coriander, litchi, mango, mangrove forest blooms, and sesame. These crops provide substantial nectar flows that are critical for maximizing honey yields. The rest of the year, particularly the 4-5 months from July to early October, is considered the dearth season, when nectar-rich resources are limited or scarce. However, it is important to note that this period is not entirely devoid of floral resources; some wildflowers and less robust nectar sources still contribute to colony sustenance.

Additionally, there is reluctance among agricultural land and orchard owners to host beekeeping colonies due to perceived inconveniences or incidents of harassment (Baidya and Purkait, 2018; Das et al., 2023). Reports indicate that while honey bees are capable of foraging up to 10 km from their hives, positioning colonies far from foraging sites is not ideal.

NUTRITIONAL MANAGEMENT: A PILLAR OF SUSTAINABLE BEEKEEPING

Bees select their foraging resources primarily based on their nutritional requirements, carefully choosing sources that offer optimal nutritional rewards. Vaudo et al. (2020) highlighted variations in the protein-to-lipid (P : L) ratio preferences among different bee species, underscoring the diversity in their dietary needs. In an investigation, Ghosh et al. (2020) demonstrated that honey bee foraging preferences for pollen are influenced by the nutritional content, specifically the total proteinogenic amino acid content, of the available floral resources. This suggests that the nutritional composition of floral resources significantly influences foraging behavior and preferences.

One of the significant challenges faced today is inadequate nutrition for honey bees, which is a contributing factor to colony declines (Dolezal and Toth, 2018; Branchiccela et al., 2019). Although extensive studies on bee health specific to West Bengal are limited, there is evidence correlating poor nutrition with colony weakening in various regions globally (Mull et al., 2022). Research has highlighted this issue, emphasizing the need for better nutrition management. Understanding and effectively managing the nutritional status of honey bee colonies is crucial for optimizing the use of the region’s abundant floral resources. For instances, the nutritional composition undergoes significant changes as pollen is transformed into bee-pollen, then into pollen patties, and finally into bee bread, which is the form honey bees actually consume (Ghosh and Jung, 2020, 2022). Notably, the protein content, particularly proteinogenic amino acids, varies across these forms, highlighting the dynamic nutritional profile during these transitions (Ghosh et al., 2024). During the year, beekeeping in West Bengal rely on seasonal floral resources for nectar and pollen. A dearth period typically occurs from late monsoon to late autumn, though it may vary slightly based on the specific geographical area and floral composition, necessitating supplemental feeding to sustain colony health (Fig. 2). In the state, the dearth period in beekeeping is not characterized by a complete absence of floral resources, as seen in many colder temperate regions. Instead, it is marked by a relatively lower availability of nectar and pollen, which may support some bee activity but in reduced quantities. Providing supplemental feeds, such as pollen patties in addition to the commonly used sugar syrup, can be particularly advantageous during periods of dearth, before the availability of major winter (rabi) crops as represented in Fig. 2.

Fig. 2.

Annual cycle of floral resources for honey bees in West Bengal, India, highlighting the dearth season which may vary based on specific geographical region and emphasizing the need for supplemental nutrition.

This enhanced nutritional support not only fortifies colony strength but also reinforces the long-term sustainability of beekeeping as a reliable livelihood. To ensure optimal bee health, it is essential for beekeepers to monitor both the diversity and quantity of pollen collected by their colonies. This practice helps in identifying any potential nutritional deficiencies and allows for timely corrective measures to be implemented. Additionally, assessing the nutritional quality of the pollen collected can further inform targeted supplementation strategies, ensuring bees receive a balanced diet that promotes robust colony health and productivity.

ADDRESSING KNOWLEDGE GAPS AND CONSTRAINT IN WEST BENGAL’S BEEKEEPING INDUSTRY

The constraints facing beekeeping in West Bengal, particularly when viewed through the lens of honey bee nutrition, highlight a critical gap in the sector’s development. One of the fundamental challenges in improving beekeeping practices in the region lies in the limited understanding of what pollen honey bees are consuming, in what quantities, and the nutritional quality of this pollen. This lack of insight creates significant barriers to optimizing colony health, honey production, and the broader growth of the industry. Fig. 3 provides the negative consequences of the inadequate nutrition of the honey bee colony.

Fig. 3.

Negative consequences of poor or inadequate nutrition of honey bee.

THE NEED FOR INVESTIGATION

Given these constraints, it is imperative to investigate the nutritional quality of the pollen that honey bees are consuming in West Bengal. Detailed research into the types of pollen available, their nutritional composition, and the quantities that bees are able to collect will provide critical insights into the nutritional status of colonies. Such investigations will enable beekeepers to identify periods of nutritional scarcity, optimize feeding strategies, and ensure that colonies are receiving the proper nutrients needed for optimal growth, health, and productivity.

In addition, understanding the seasonal variability of pollen quality and availability will empower beekeepers to adjust their practices accordingly, either by supplementing with additional nutrients or by moving their colonies to areas with more abundant or higher-quality pollen sources. Addressing the gaps in nutritional knowledge can significantly enhance the sustainability of beekeeping in West Bengal, boosting both the health of bee populations and the economic viability of apiculture.

Furthermore, due to climatic conditions, the blooming periods of plants, including essential bee flora, may vary (Tun et al., 2021). Therefore, it is important to investigate if any changes are occurring at present.

CONCLUSION

Beekeeping plays a vital role in sustainable agriculture and economic development. Addressing the constraints of apiculture in West Bengal, such as diversifying hive product use, improving nutrition management, and fostering better cooperation with landowners, can propel the industry toward greater resilience and growth. By expanding beyond honey production and promoting the collection of pollen and other hive products, beekeepers can unlock new opportunities for income generation and contribute to the broader health of honey bee populations, which are essential pollinators for global food security.

Acknowledgments

This study was conducted as part of the “Glocal University Project Group in Andong National University-Gyeongbuk Provincial College” supported by the Ministry of Education and National Research Foundation of Korea.

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