1910] Graenichcr, Red Clover and Bumblebees in New Zealand. 169 



cially frequent. Both of these species show a wide range of dis- 

 tribution. 



The figures presented above (tongue-length) were all derived 

 from females (queens). Around the middle of June the workers 

 begin to fly and are present in great numbers throughout the sum- 

 mer months. There is a considerable difference in size among the 

 workers belonging to the same species, the larger ones being 

 termed major workers, those of smaller size the minor workers. 

 Four such workers of Bombus pennsylvanicus, repesenting dif- 

 ferent sizes, were selected and their tongue-lengths determined 

 as follows : 



1. Body length 17 mm. Tongue length 11 mm. 



2. " " 1.5 mm. " " 9 mm. 



3. " " 11 mm. " " 6 mm. 



4. " " 9 mm. " " 5 mm. 



From this we gain the information that not only the female, 

 but also the larger workers of this species are able to figure as 

 efficient pollinators of the red clover. For the purposes under con- 

 sideration the introduction of B. pennsylvanicus as also of B. 

 americanorum into any foreign country with suitable climatic con- 

 ditions would probably prove satisfactory. Both of them are 

 hardy and vigorous, and might, in the case of New Zealand, be 

 able to counterbalance the harmful activity of Bombus terrestris, if 

 numerically well represented. 



Milwaukee Public Museum, 

 October, 19, 1910. 



