台灣產四種熊蜂（膜翅目：蜜蜂科）之族群形質比較、季節性發生及分佈特性之研究

The population characteristics, seasonal occurrence of colonies, and distribution features of the common bumblebees, Bombus bicoloratus, B. eximius, B. flavescens, and B. trifasciatus from Taiwan were studied. We examined over 800 specimens from four deposits starting in the 1970s and from additional data from field collections. Our results indicate that the four general ecological features for these bumblebees are: (1) The effect of latitudinal distribution differences within the same species seems not to be an important factor. All four species have relatively large populations above 1,000 m in altitude. (2) The slight morphological difference in female abdomen tends to be a continuous variation in size between the queen and the worker caste. On the contrary, the size variation is biased discontinuously. (3) The colony among the four species seems not to be permanent development. Whether the queens overwinter or not needs to be confirmed. (4) The species are distribution based on the local flora and habitats. It seems that there is a partitioning of the resources in selected flowering areas. The ecological features for the specific species are: (1) B. bicoloratus tends to be a warmer weather adaptive species. The size difference between the queens and the workers seems discontinuous. (2) The foundress of B. eximius appears early in autumn. Colony development attains on the plateau in the spring, and then the number of workers diminishes in the field during the hot season. (3) The size differences between the B. flavescens foundress and the B. eximius worker are slight, and the occurrence of both species overlaps in the spring. The size difference between the queens and the workers of B. flavescens seems to be continuous. Apparently continuously size variation is a beneficial survival strategy for this species. (4) B. trifasciatus tends to be a cooler weather adaptive species above 1,000 m in altitude. The flower preference of this species tends to be more distinct compared with the other species.