Objective To identify the damage symptoms, species composition, spatio-temporal dynamics and host preferences of thrips that are harmful to honey pomelo during its flowering period.

Method Pomelo orchards planted with traditional managements in Pinghe County, Zhangzhou City, were selected for investigation. Thrips on different pomelo varieties, including traditional red pummelo, white pummelo, and newly introduced grapefruit, red grapefruit and tanglo, were examined during the flowering period. Thrips were identified based on morphological characteristics. The species and abundance of thrips on pomelo at different sampling dates, varieties, and altitudes were recorded. Damaged young fruits were collected and tested for nutritional quality.

Results Thrips infestations resulted in circular scars around the fruit stem and negatively impacted the nutritional composition of both the peel and pulp of the young fruits. The peel's moisture and dry protein content were significantly reduced, whereas the ash and total sugar content increased significantly. In the pulp, only the dry protein content showed a notable decrease. Furthermore, thrips in pomelo flowers comprised a mixed species population, including Thrips hawaiensis, Frankliniella intonsa, Scirtothrips dorsalis and Thrips anderwsi. Analysis showed that the dominant species was Thrips hawaiensis, accounting for 74.9% - 88.8%. Additionally, there was a significant impact of varieties and altitudes on the occurrence of thrips during the flowering period. The thrips population of peaked in early April. The occurrence of thrips on flowers in high-altitude pomelo orchards was significantly higher than that in middle and low altitude orchards. Moreover, the occurrence of thrips on relatively traditional varieties, such as red pummelo and white pummelo, was significantly higher than that on newly introduced varieties such as grapefruit.

Conclusion Thrips during the pomelo flowering period not only affect the appearance quality of pomelo but also its internal nutritional quality. The dominant species of thrips during the flowering period of pomelo is T. hawaiensis, which requires prioritized prevention and control. Furthermore, it is necessary to consider flowering period, altitudes and varieties when making targeted control measures in pomelo orchards.