The most likely outcome of the change in the ecosystem, given the reduction in bee population due to an increase in bee predators, would be: The plant community will become smaller and less diverse.
This is because many plants specifically depend on bee pollination for reproduction. A significant decline in bees would lead to reduced pollination, resulting in lower seed production and potentially smaller populations of those plants. Over time, this could reduce the overall diversity of the plant community, as bee-pollinated plants may be unable to sustain their populations without adequate pollination.