I've long planted crocuses in abundance precisely because they provide early food for bees. In my garden (Arlington) I've seen several honeybees and one precocious bumblebee this season. Other years I've seen smaller bees (I suspect native?) with the crocuses, but I haven't spotted them thus far this year.

One of my goals as a gardener is to provide non-stop bee-food from first crocus through Thanksgiving. So from my point of view, crocuses are quite ecologically significant.