Species account taken from "THE MEGACHILINE BEES
OF CALIFORNIA (Hymenoptera: Megachilidae) Authors: PAUL D. HURD, JR and CHARLES D. MICHENER Source: BULLETIN OF THE CALIFORNIA INSECT SURVEY VOLUME 3 (May 31, 1955) pp. 1-248"
Megachile variolosa Gesson, 1872, Trans. Amer.
Ent. SOC., 4:270, 9. Type 9, Texas (Acad.
Nat. Sci. Phila.).
Synonyms: odontophora Schletterer, 1889; asteris
Cockerell, 1897; barbatus Robertson, 1903,
3, not 9; productus Robertson, 1905.
Geographic range: Ontario to North Carolina, west
to British Columbia, Oregon, Utah, New
Mexico, and Texas. Another subspecies (H.
variolosa purpurascens Cockerell) ranges from
Texas to Yucatan (see map 1).
There are no California records of this species,
but it has been collected at Baker, Oregon
(Michener, 1938:520) and at North Powder, and
13 miles east of Juntura, Oregon, and may, therefore,
be expected to occur in northeastern California.
At the latter two localities this bee has
collected on Solidago.
This bee has been found to visit a variety of
flowers. In Nebraska, where perhaps the majority
of floral visitation records have been kept, we
have the following information: At Cams, flowers
Amorpha, Helianthus, Heliopsis helianthoides,
Malva silvestris, Mentha, Monarda, Ratibida,
Vernonia, and thistle. At Glen, flowers Gutierrezia
sarotbme, Mentha canadensis, and Solidago.
At Monroe Canyon, Sioux Co., flowers Solidago.
Neligh, flowers thistle. At Nebraska City, flowers
thistle. At Omaha, flowers Melilotus alba and Solidago tigida. At Red Cloud, flowers Thelesperma
gracile. At Warbonnet Canyon, Sioux Co.,
flowers Melilotus and Monarda. At Weeping Water,
flowers thistle. At West Point, flowers choke
At Beach, North Dakota, variolosa has been
taken at flowers of Grindelia. P. H. Timberlake
has found it collecting pollen from Erigeron
philadelphicus at Mengus Mills, Pennsylvania.