What substance provides the primary energy source for the adult yellow-faced bee?
Answer
Nectar
The primary energy source required for the flight, foraging activities, and general metabolic needs of the adult yellow-faced bee is nectar. Nectar is a sugar-rich liquid collected directly from flowers during visits. While pollen is critically important, its primary purpose is reserved for nourishing the developing larvae, whereas the immediate fuel demands of the active adult insect are met by consuming the sugars found in nectar.

Related Questions
What substance provides the primary energy source for the adult yellow-faced bee?Where do *Hylaeus* bees store the mixture of pollen and regurgitated nectar for their young?Unlike honey bees, what structure do *Hylaeus* bees specifically *not* use for external pollen packing?What foraging strategy characterizes yellow-faced bees across their native ranges in North America and Hawaii?What vulnerability arises because *Hylaeus* stores contaminated pollen internally?What is the resulting nutritional form of the pollen mixed with nectar for *Hylaeus* larvae?Why does the lack of specialized hair in *Hylaeus* reinforce the need for internal pollen mixing?For native bee conservation, what generalist diet requirement necessitates a diversity of available plants?What aspect of flower characteristics matters less to yellow-faced bees compared to bees with specialized leg structures?What is the benefit potentially derived from the upfront energetic cost of mixing nectar and pollen internally for *Hylaeus*?