Colletes stepheni Timberlake 1958

Colletes stepheni Timberlake

This species is a rarely collected spring species thus far known only from the Colorado Desert in Riverside County, California. It is matinal in pollen-collecting activity, the foraging flights occurring primarily from just before sunrise to an hour and one-half after sunrise (0450–0620 hours in mid-April) (Hurd and Powell, 1958). Large numbers of individuals of both sexes have been taken at Larrea 18 miles west of Blythe, California (type-locality), and a few females at Cercidium floridum in the company of Martinapis luteicornis (Timberlake, 1958b).

An account of the nesting habits of this species in sand dunes at the site near Blythe, where the females were storing Larrea pollen, has been given by Hurd and Powell (1958). They record evening flights of males at the nest site involving large numbers of individuals. The flights began about an hour before sunset, reached a peak about a half-hour before sunset and diminished rapidly as they continued into the twilight period. During the night the males slept in large numbers on dead stems of Galleta grass (Hilaria rigida), clinging with their legs and facing head downward.