Osmia pedicornis are black bees with a slightly blue or green luster to the thorax and abdomen (Wu 2006). Females have long, upright, white hair mixed with black and brown long hairs on the head; the scutum has intermixed black and yellow-brown hairs; and the episternum has primarily pale hair (Fig 2). T1–T2 have yellow-brown hair, and T3–T5 have dark brown or black hair (Wu 2006). Males have dull yellowish hair with a mixture of black on the head, thorax, and legs (Yasumatsu and Hirashima 1950). Female body length is 15–17 mm, and male body length is 10–11 mm (Wu 2006). O. pedicornis is used commercially as an apple tree pollinator in Japan (Kitamura and Maeta 1969).
(modified from Wu 2006)
Osmia pedicornis look similar to O. rufina and O. bicornis. Females of these species all have lateral horns and bidentate median apical projection on the clypeus. O. pedicornis can be differentiated by the bifurcate apex of the lateral horns of the clypeus. Males are similar in size and hair color and can be difficult to distinguish without dissecting them to see the genitalia and hidden sterna. They can, however, be distinguished by the shape of S8 and the apex of the gonocoxites.
Osmia pedicornis adults have been recorded in flight between March and June with the majority of specimens recorded through April and May (GBIF 2019f).
Osmia pedicornis collect pollen from flowers that produce little to no nectar (Quest 2009). O. pedicornis is known to be a generalist, collecting pollen from Rosaceae, Geraniaceae, Caprifoliaceae, Elaeagnaceae, and Fabaceae (Quest 2009).
Osmia pedicornis nests can be found in cracks within bark or rotten wood, crevices between twigs and stalks, under stones, or inside cracks in soil (Maeta 1978). Nesting habit will be typified by the abundance of nesting sites; cell partitions and plugs are composed of leaf pulp or mud (Maeta 1978). O. pedicornis will forage up to 700 meters from their nesting site (Maeta 1978).