24 ENTOMOLOGICAL SOCIETY 



further said that Haliday had considered the Bembecidae as rather 

 closely related to the bees, on account of the structure of the 

 mouth-parts. Mr. Ashmead also said that there was a strong 

 affinity between certain wasps, the Larridcc and Nyssonidce, 

 and some of the parasitic bees. 



//</ FEBRUARY 6, 1896. 



President Marlatt in the chair and the following members also 

 present: Messrs. Linell, Gill, Schwarz, Fernow, Patten, Judd, 

 Chittenden, Stiles, Ashmead, Howard, Benton, active members, 

 and Messrs. G. R. Stetson, E. T. Perkins, E. C. Barnard, and 

 Dr. W. J. Karlsioe, visitors. 



Mr. Schwarz read the following communication : 



SLEEPING TREES OF HYMENOPTERA. 

 By E. A. SCHWARZ. 



Comparatively little attention has been paid by entomologists 

 to the attitudes assumed by insects during the periods of sleep. 

 Crepuscular or nocturnal insects such as Heterocerous Lepidop- 

 tera, which sleep during the day-time, can of course be readily 

 observed at that time, and the very characteristic attitudes of 

 many lepidopterous larvae while asleep or at rest have frequently 

 been described and figured. In diurnal insects, which sleep at 

 night, such observations are not readily made. There is no 

 question, however, that various observations and notes on the 

 subject are recorded, and I distinctly remember having read an 

 account of the sleeping habits of certain bees or wasps, but I 

 am unable to refer to it now. 



Thus, at the risk of duplicating an observation already pub 

 lished, I beg to narrate shortly a little experience I had the past 

 year in southwestern Texas, regarding sleeping Hymenoptera. 

 There are three species concerned in this observation, which were 

 kindly determined by Mr. Ashmead. Two of them, Melissodcs 

 pygmczus Cress, and Ccelioxys texanus Cress., belong to the 

 family Apidrc ; the third, Coloptera ivrightii Cress., to the 

 Sphegidae. All three are extremely abundant in southwestern 

 Texas. 



During the extremely dry weather in the spring a peculiar cli 

 matic condition prevails in southwestern Texas, day after day, 

 in the early morning hours. From about 5 o'clock until after 



