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We studied the floral ecology, floral visitors and breeding system of Citrus × limon in West Bengal, India. We calculated a coefficient of pollination deficit (D) and also estimated the values of 'relative pollinator service (RPS)' to determine primary polli nators of the plant species. The cultivar is fully self-compatible and produces protandric hermaphrodite flowers and male flowers with considerable amount of floral rewards. Several insects like honey bees, solitary bees, carpenter bees, flies and butterflies visited the flowers. Among those, primary pollinators were Halictus sp. and Nomia sp., and important secondary pollinators were Apis dorsata and Xylocopa fenestrata. Considering the visitors' group, the cultivar is principally pollinated by solitary bees. Besides diverse floral visitors, the cultivar showed medium pollination deficit (D = 0.49) and resulting in low fruit-set. Furthermore, premature fruit abortion is also high in all pollination treatments which lead to a low fruit-set of this lemon variety in West Bengal.

Flowering plants and pollinators are in a mutualistic association, where pollinators collect floral resources and plants receive pollination services. Bees and other pollinators are declining in many parts of the world, and their loss affects the functional composition of fauna, flora, and habitats. Different strategies are being deployed to improve pollinator services, including the management of bees. Sustainable management of a bee species strongly depends on floral resource availability. Therefore, beekeepers need to have adequate knowledge about the surrounding vegetation (especially nectar and pollen sources for the bee species). Diverse methodologies are used around the world to determine floral resources for bees. Field surveys and pollen analysis of honey, corbicular/scopal pollen loads, residual pollens in brood cells, forager’s body surface pollen content, and internal organs (gut, intestine, crop, etc.) were used by the researchers. For pollen identification, most researchers carried out microscopy-based methods. However, pollen DNA-based methods were also used by researchers in recent years. Regarding the morphology-based identification, most researchers processed pollen samples according to Erdtman’s acetolysis method to increase the visibility of diagnostic characteristics of the pollen grains. The method specified by the International Commission for Bee Botany was used to conduct qualitative and quantitative pollen analysis on honey samples. For quantitative pollen load analysis, researchers used numerous techniques that may have been the most effective. Our discussion about the different techniques utilized to determine floral resources of a bee species will be helpful for researchers in selecting a suitable protocol and may assist in developing superior methodologies.

Besides its importance as an ornamental plant, Justicia betonica L. is also used as a medicinal plant for the treatment of several human disorders. However, the population size and abundance of the plant species are very low in Indian states, including West Bengal. The breeding system and pollination ecology of J. betonica are still unclear. Therefore, some reproductive aspects were investigated in order to provide important information for the sustainability of the species. The flowering duration spanned from December to May, with its peak in February–March. Flower opening time was much earlier (5.00–8.00 a.m.) on a hot day (in April–May) than on a cold day (10.00 a.m.–12.00 p.m. in December–January). The time of anther dehiscence coincided with the flower opening time; however, the stigma became receptive later. The plant species is self‐compatible but dependent on pollinators for fruit and seed sets. Members of different insect groups like ants, bees, butterflies, flies, moths and wasps visit the flowers. Among them, Allorhynchium metallicum and Halictus acrocephalus are the primary pollinators (based on the “relative pollinator service”). The plant species showed a significant pollination deficit (coefficient of pollination deficit [D] = 0.32) in the open condition. Larvae of the florivorous moth Gatesclarkeana erotias significantly reduced reproductive success by eating their floral parts, ovules and immature seeds. In conclusion, combining the pollination deficit and the feeding activity of phytophagous insects (moth larvae) may reduce the reproductive fitness of J. betonica in the study regions.