Under the family Andrenidae is the species Macrotera portalis, in which observations have suggested it is oligolectic. Macrotera portalis is a communal, ground nesting bee that has been found to preferentially pollinate certain host flowers of the same species.[1] Andrena agilissima is another oligolectic mining bee that prefers different types of wild mustard and radish plants.[2] Attempts have been made to determine whether this narrow host preference is due to an inability of the bee larvae to digest and develop on a variety of pollen types, or a limitation of the adult bee's learning and perception (i.e., they simply do not recognize other flowers as potential food sources), and most of the available evidence suggests the latter. However, a few plants whose pollen contains toxic substances (e.g., Toxicoscordion and related genera in the Melanthieae) are visited by oligolectic bees, and these may fall into the former category.