Complex sentence: Most of these bees are solitary bees, not living in colonies like European honeybees, and most live for only three to four weeks, and since flowers bloom here throughout the growing season, many niches are available for all the bee species.
Split into simpler sentences: Most of these bees are solitary bees, not living in colonies like European honeybees, and most live for only three to four weeks. And since flowers bloom here throughout the growing season, there are many niches for all the bee species.