410 THE. CANADIAN ENTOMOLOGIST 



Mrs. C. Bennett, in August 1908, took males of M. parallela Sm. 

 and M. manifesto, Cr., at flowers of Helianthus at Denver. 

 M. augustini Ckll., o 71 , was collected at Boulder, Aug. 8, on 

 II. annuus coronatus. Male bees visiting sunflowers get covered 

 with pollen, and must be almost as useful as females. 



At Sterling, Colorado, far out on the plains, I collected bees 

 from H. annuus lenticularis on Aug. 3, 1911. Several of the species 

 (Canad. En torn., Nov. 1911, p. 390) were the same as those found 

 at Boulder, but others were present, and, in particular, 

 Anthophorula bruneri (Crawf.) was abundant and evidently an 

 important factor in pollination. 



The above lists happen to lack now other types of bees which 

 are more or less important visitors of sunflowers in Colorado; 

 Bombus and the Anthidiines. The Bombi on sunflowers are 

 principally males, and the same is true in European gardens, as 

 may be seen by the list in Knuth's "Bliitenbiologie." The 

 Anthidiines (at Boulder Heteranthidium zebratum (Cr.), Dianthidium 

 perpictum Ckll., and D. sayi Ckll.) and efficient, but not abundant 

 enough to be of great consequence. 



In suitable localities, Perdita abounds on sunflowers. Thus,. 

 in Nebraska (Swenk and Cockerell, 1907) eight species are 

 recorded, some of them regular visitors, others only occasional. 

 In Nebraska and New Mexico, P. altipennis and its immediate 

 allies (subgenus Cockerellia Ashmead) are especially found on 

 Helianthus, though there are members of this group attached to 

 other Helianthoid Compositae, as Ratibida and Ximenesia. 



Diadasia cannot be regarded as a normal or regular visitor of 

 Helianthus, yet it occurs from time to time. I collected males of 

 D. australis Cr. on sunflower at San Bernardino, California, many 

 years ago; and females of D. enavata Cr. on II. lenticularis at 

 Mesilla, New Mexico. 



At Falfurrias, Texas, May 18, 1907, Mr. A. C. Morgan collected 

 one female each of D. australis Cr. and D. afflicta Cr., at flowers of 

 Helianthus. The D. australis had collected much yellow pollen on 

 the hind legs, but the large smooth grains were apparently 

 cactaceous, certainly not from Helianthus. However, the compound 

 microscope showed also a small quantity of the small grains of 



