Megalopta nocturnal bee, Soberania N.P., Panama
These sweat bees (genus Megalopta) are unique in that they forage in the evening and at dawn, well outside the normal foraging times of other day-flying bees. Here, a sweat bee arrives at a balsa-tree flower under cover of darkness. The bee is about the size of a honeybee, and the flower is about as big as a coffee cup. (Photo credit: Christian Ziegler)