This study assessed the pollinator fauna of guava (Psidium guajava) plantations at ICAR-CISH, Lucknow during the 2024 rainy and winter flowering seasons. Weekly field observations were conducted from 10% flowering until completion, recording pollinator visitation rates and relative abundance across different times of the day. Apis dorsata emerged as the dominant pollinator, with an average of 65.76 visits per five flowers per five minutes (33.19% relative abundance) during the rainy season, increasing to 74.56 visits (44.47%) in winter. Apis cerana indica and Ceratina spp. were the next most abundant species. Peak activity occurred between 6:10–8:45 AM and 4:00–5:15 PM. The findings highlight the significance of native bee species in guava pollination under intensive cultivation systems.

Guava (Psidium guajava), Pollinator fauna, Apis dorsata, Apis cerana indica, Ceratina spp.

Pollination is a fundamental ecological process essential for the reproduction of flowering plants, supporting biodiversity and food security (Omar et al., 2021).  About 87% of flowering plants and 87 of the leading global food crops rely on pollinators for seed production (Brunet and Fragoso 2024). Insect-mediated pollination significantly enhances the productivity and quality of many fruit crops, including guava (Psidium guajava L.), a nutritionally rich tropical fruit (Vinod and Sattagi 2018; Omar et al., 2021). Guava, enriched with citric acid, minerals, and vitamin C, ranks as the fourth most cultivated fruit in India, with a production of 5.59 million metric tonnes in 2023. Due to the flower morphology, where the stigma protrudes above the anthers, self-pollination is rare in guava (Pommer and Murakami 2009). Approximately 35-40% of pollination is facilitated by insect vectors, improving fruit set and quality (Singh, 2020). Key pollinators include Apis dorsata, Apis cerana indica, and Apis florea, while Diptera and Lepidoptera contribute to a lesser extent (Vinod and Sattagi 2018; Singh and Thakur 2017). Pollinator activity varies with environmental factors, typically peaking in early morning and late afternoon under subtropical climates. However, the decline of pollinators due to chemical-intensive agriculture threatens this vital service. This study aims to document the diversity and relative abundance of guava pollinators under subtropical conditions.

The study was conducted in the guava plantation (var. Shweta) of ICAR-CISH, Lucknow. Field observations were carried out over two consecutive flowering seasons during the rainy season (April-May) and winter season (October-November) of 2024. Guava trees of the same age (7-10 years) and with similar canopy growth were selected for the study. Observations on pollinator visitation began when flowering reached 10%. Since anthesis starts at 4:00 AM and lasts until 10:00 AM in guava trees, data collection took place at 06:00 AM, with observations lasting five minutes on five randomly chosen flowers from five randomly selected trees. These observations were recorded weekly until flowering was complete. Representative samples of each pollinator species observed during the study were collected, preserved, and identified. The identified species were counted, averaged, and categorized by order to analyze the pollinator fauna associated with guava. Additionally, data on the relative abundance of pollinators were collected at 10% flowering by recording visits from various pollinator groups at 8:00 AM, 10:00 AM, 12:00 PM, 2:00 PM, and 4:00 PM. Observations were made on five randomly selected flowers from five trees for five minutes at each time point. The relative abundance of different pollinator species was calculated using a specific formula and expressed as a percentage.

Relative abundance of species = (Number of insect species visited/ total numbers of pollinators visited)/100

Different pollinator species were identified as, Apis dorsata, Apis cerana indica, Ceratina spp., Xylocopa spp., Tetragonula iridipennis, Danaus spp. Table 1 indicate the pollinator fauna in guava ecosystem during two consecutive flowering seasons of 2024. During April-May (rainy season guava), average number of Apis dorsata per 5 flower/ 5 min was about 65.76 with relative abundance of 33.19%. Whereas, during Sep-Oct (winter season guava), average number per 5 flower/ 5 min was about 74.56 with relative abundance of 44.47%. During April-May (rainy season guava), average number of Apis cerana indica per 5 flower/ 5 min was about 55.87 with relative abundance of 28.20%. Whereas, during Sep-Oct (winter season guava), average number per 5 flower/ 5 min was about 49.77 with relative abundance of 27.12%. Overall pooled data indicated that over two seasons, Apis dorsata visited in highest number (70.16) / 5 flowers/ 5 minutes followed by Apis cerana indica Fab. (49.77) and Ceratina spp. (34.67). The transit time period of the visitors were found during 6.10 AM - 8.45 AM and 4.00 PM -5.15 PM. The foraging speed and transit time of all flower visitors have been studied.

1.                        (b)                           (c)

Fig. 1.  (a) Apis dorsata, (b) Apis cerana indica and (c) Ceratina spp. pollinating guava flowers.

Table 1: Pollinator fauna in guava ecosystem during April-May, Sep-Oct of 2024.

Snehasish Routray, H.S. Singh, Yogendra Kumar and Rajneesh Kumar Verma (2025). Relative Abundance of Pollinators in Guava under Subtropical Conditions. Biological Forum, 17(5): 68-70.