Vol. xxiii] ENTOMOLOGICAL NEWS 459 



pollen from plants of the same genus, but each of the other 

 ten has its own flower, so there are eleven sets which are 

 absolutely without competition among themselves. I think it 

 is clear that so many species could hardly flourish in the same 

 locality and complete their flight in so short a time, if all were 

 in competition for the pollen of the same flowers." This 

 refers to vernal Andrenas and the four species are oligo- 

 tropes oj^Sali.\-. If the several species of Sali.v afford an un- 

 usuatfyrich supply of pollen, it is not inconsistent with the 

 theory of avoidance of competition, if several oligotropic An- 

 drenas compete for their pollen. 



Lovell also says: "The social bees, as a rule, visit a great 

 variety of flowers, though in Europe it is stated that there 

 is a bumble-bee (Bomb us gerstackeri) which visits a single 

 species of monkshood (Aconitum lycoctonum)." In this form 

 the case is a nature-fake, as pointed out in the Botanical Ga- 

 zette 28:34, 1899. In his Handbuch der Bliitenbiologie. 114, 

 Knuth says that Bomb us gcrstlickeri visits exclusively the 

 flowers of Aconitum lycoctonum. This is simply a misstate- 

 ment of an observation of Dalla Torre. This author did not 

 say and did not suppose the B. gerstdckeri limited itself to A. 

 lycoctonum, but only the female did. The males and workers 

 have different habits and the difference was designated by the 

 term Heterotroph\. Not even does the female limit itself to 

 A. lycoctonum, for it was observed by Frey-Gessner and Hoffer 

 on A. napellus (Vol. 2:52, 54). This still limits the female to 

 Aconitum. They are apt to spoil this, if they keep on observing 

 the habits of B. gerstdckeri. 



In a paper on Colletes (Univ. Neb. Cont. Dept. Ent. No. i) 

 on page 14, Mr. M. H. Swenk refers to my statement that C. 

 brci'icornis is an oligotropic visitor of Specular ia perfoli- 

 ata and says : "In Nebraska, however, it visits also the closely 

 allied Campanula rotundifolia, while I have a female taken on 

 Melilotus alba. In Texas it occurs on Callirhoc hirolucrata and 

 Asclepias latifolia, while the types of opuntiac were taken 

 on Opuntia and Campanula." I have taken the male on Pasti- 

 naca and the female on Psoralca. Mr. Swenk evidently mis- 



