Investigation on pollinator diversity of Camellia oleifera in Gannan

This research was conducted to elucidate the species composition, abundance patterns, and community variation of pollinating insects associated with Camellia oleifera in southern Jiangxi (Gannan), thereby providing a scientific foundation for their conservation and rational utilization.

During the main flowering seasons of C. oleifera from 2022 to 2023, a comprehensive field survey of pollinating insects was carried out in 18 plantations across the region. Community characteristics were evaluated using the Shannon-Wiener diversity index, together with indices of species richness, evenness, and dominance.

In total, 2,334 pollinating insects were collected, representing 21 species from 15 genera, 13 families, and 3 orders, with Hymenoptera and Diptera identified as the dominant orders. Among these, Vespidae, Syrphidae, and Apidae comprised 28.11%, 21.77%, and 11.87% of all pollinators, respectively. The largest number of individuals was observed at the Shuangzhen C. oleifera base in Xiafeng Village, Shashi Town, Zhanggong District, whereas the fewest were recorded at the Qingjiangpai base in Dutou Village, Gangmian Township, Ruijin City. Species richness and diversity values reached their maximum at the Laoyangtian base in Xiuluo Village, Ziyang Township, Shangyou County, and were lowest at the Dashuishan base in Chazi Village, Pangushan Town, Yudu County. A strong positive correlation was detected between the Shannon-Wiener diversity index and the Chao1 richness index (R = 0.735, P < 0.01). The highest evenness index occurred at the Shizipai base in Wanxing Village, Datangbu Town, Xinfeng County, while the lowest was recorded at the Shanxia base in Shima Village, Liuche Town, Xunwu County. The greatest similarity in pollinator community composition was observed between the Laoyangtian base in Xiuluo Village, Ziyang Township, Shangyou County, and the Daoping base in Makou Village, Shadi Town, Ganxian County (Cs = 0.968). Conversely, the lowest similarity occurred between the Qiaokeng base in Mixi Village, Jiubao Town, Ruijin City, and the Shuangzhen base in Xiafeng Village, Shashi Town, Zhanggong Distric (Cs = 0.519)

Apidae, Vespidae, and Syrphidae were identified as the key pollinator groups of C. oleifera. The Asian honeybee (Apis cerana) demonstrated high potential for effective pollination of C. oleifera. It is therefore suggested that suitable nectar- and pollen-producing plants be interplanted within or along the margins of C. oleifera stands to create stable habitats and support sustainable bee-mediated pollination.