Pollination plays a huge ecological and economic role in nature and in civilization. The agriculture industry relies heavily on insect-driven pollination for fruit production. Likewise, many angiosperms depend on insect pollination for fertilization and reproduction. This study outlines bee and fly pollination habits in a subalpine meadow near Molas Pass in the San Juan Mountains, Colorado, which is an undersampled region for pollinators. The objectives of this study were to determine the seasonal abundance of bees and flies, as well as to examine their pollination habits focusing on flower species and resource preferences. In the meadow, 40 1m2 plots were established. Within each plot, pollinator visitation and resource collection were recorded over a 5-minute period every 3-4 days between June and September. Bees and flies not identified in the field were collected for later lab identification. Flies visited twice as many different flower species as bees, were present in much greater numbers, and were consistently observed solely collecting nectar. In response to increases in precipitation mid-season, bee prevalence decreased significantly while fly visitation rates were unchanged. Differing pollination strategies between bees and flies, along with changes in weather patterns leading to shifts in mid-season flowering time, could have consequences for future pollination patterns, especially at higher elevations.
