1916] The Sleep of Insects 



247 



late, for on August 18 six honey-bees were seen in the newly 

 opened flowers of the jimson-weed, while the same week many 

 were to be seen flying from flower to flower covered with green 

 pollen at the early morning hour of 5:45. 



Emphor bombiformis Cress. [H. L. Viereck]. 

 Seven individuals of this species came to the elderberry 

 bush in my garden while it was still Hght ; at 9 o'clock they were 

 m such deep sleep that they could easily be marked. Owing 

 to poor light however, the work was awkwardly done, and the 

 next morning two were found disabled. The others never 

 returned. 



Triepeolus helicanthe Rob. [J.' C. Crawford]. 



Triepeolus lunatus Say. (J. C. Crawford]. 



Triepeolus concolor. [J. C. Crawford]. 



Triepeolus concavus Cress. [J. C. Crawford]. 



We have discovered no hard and fast rules for the sleep of 

 these Httle bees, excepting that, like most bees, they faithfully 

 keep regular hours, from about 6:30 p. m. until the sun is well 

 up in the morning, and that they habitually choose a leaf or 

 twig of a weed about two feet above the ground as their resting 

 place, although the vegetation was of various heights from 

 two to six feet. 



The specimens of T. concolor which we have seen were 

 simply sleeping on stems in the position they assume during the 

 day. Our three individuals of T. concavus followed each his 

 own fancy in settling to rest; one was curled around a stem, 

 another tightly clasped a leaf of Erigeron with its mandibles 

 while Its legs were free and the body horizontal, and" the third 

 assumed a comical position, just hanging over a little stem by its 

 middle like a small boy hanging over a rail fence on his stomach. 

 The httle T. lunatus were found still in deep sleep at 6:35 on 

 an August morning. They were sitting in an easy, natural 

 attitude, each on the top of an Erigeron leaf, and they were so 

 helpless at this hour that when brushed off they fell down as 

 if dead. 



We have observed T. helicanthe upon only two occasions. 

 They were grouped in small colonies of three and five. In every 

 case they clung to a little stem by the mandibles while the feet 

 rested Hghtly upon the vegetation and the body rested head 

 downward. 



