POLLINATION OF RED CLOVER BY TETRALONIA AND 



MELISSODES. 



Justus W. Folsom. 



The fact that bumblebees are important as pollenizers of 

 red clover has been established by means of numerous experi- 

 ments dating from the time of Darwin. Their importance in 

 this respect depends, however, upon their numbers at the time 

 when the clover is in bloom. Thus, in second-year clover, in 

 Illinois, bumblebees are highly important as pollenizers of the 

 second crop, for they are abundant in late July, in August and 

 September. They are unimportant as pollenizers of the first 

 crop, however, for in June the only winged bumblebees in 

 existence are the comparatively few queens that have survived 

 the winter, and these spend a large part of their time in the 

 nest, rather than in the field. The June crop is certainly not 

 pollenized to any considerable extent by bumblebees. In 

 fact, it seldom yields much seed as compared with the second 

 crop in the same locality. 



Twenty years ago it was taken for granted that there was 

 not enough seed in the June crop to pay for its extraction, 

 but since then more and more farmers have found it profitable, 

 now and then, to cut the June clover for seed instead of hay, 

 and have obtained from one-half a bushel to two bushels of 

 seed (possibly more) per acre in Illinois. 



How is the June crop pollenized? From correspondence and 

 from inquiries at Farmers' Institutes I learned that in a few 

 instances the yield of seed had occurred in a region where 

 Italian honey bees were common and had been seen working on 

 the flowers. Now honey bees of this race are undoubtedly 

 important pollenizers of red clover, as Dr. A. D. Hopkins 

 found, and as I have since ascertained. There were, however, 

 some instances in which seed had been obtained from the 

 June crop in places where there were no Italian honey bees; so 

 there still remained some mystery in regard to the means of 

 pollination of the clover field in June. 



Mr. W. P. Flint has had Tetralonia dilecta Cress, under 

 observation for several years, and has repeatedly found good 

 yields of seed from fields in which this bee had been abundant. 



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