Abstract: 【Aim】 For the further development and utilization of the Xylocopa resources, it is necessary to know the food plants and foraging behaviors of X. appendiculata. 【Methods】 From March to October of the past three years (2009-2011), the floral resources of X. appendiculata and its foraging behaviors were observed by visual observation and photographing in fields in Luoyang, Henan Province, central China. Characteristics of plant species utilized as its food resources were recorded. The size of holes in the corolla tube chewed by robbers was measured. 【Results】 In natural habitats, there were 52 plant species in 27 different families in Luoyang, Henan Province, central China visited by X. appendiculata, and 25 of the species were its major plant resources. The species proportions of Caprifoliaceae and Leguminosae families were dominant (17.31% and 15.38% of the total plant species visited, respectively). Sixteen of the 43 plant species were robbed by X. appendiculata, accounting for 30.77% of its visited plants. X. appendiculata prefers flowers which are usually medium-sized, zygomorphic, and purple, yellow, or white colored. Significant variations were found in size of robbing holes and flower visiting frequency of X. appendiculata in different species. Size of robbing holes in Clerodendrum bungei were the maximal (9.43±1.91 mm in diameter), while minimal (3.46±0.98 mm in diameter) in Kolkwitzia amabilis. Flower visiting frequency in Lagerstroemia indica was the highest, 25.71±2.36 flowers per minute; and the duration of each visit and interval time of X. appendiculata between two flowers in Althaea rosea were the highest, 5.89±3.34 s per flower and 2.63±2.04 s between two flowers, respectively. 【Conclusion】 X. appendiculata foraging is characterized by a wide range of food plants and long seasons of activity. Significant variations exist in its foraging behaviors and foraging frequency on different plants.

Key words: Xylocopa appendiculata, food plants, foraging behavior, nectar robbing, flower characteristics