378 THE CANADIAN ENTOMOLOGIST 



H. S. Smith, of the State Commission of Horticulture of Cali- 

 fornia. These specimens were forwarded to Mr. E. O. Essig and 

 received from him by the author. Upon its appearing that the 

 species was new Mr. Essig and Mr. H. S.Smith resigned their rights 

 to it, and Mr. Smith procured an additional supply of material. To 

 these gentlemen are due the fullest thanks for their kindness. A 

 search by the author then' revealed the species in the vicinity of 

 Stanford University, a region that still continues to yield new 

 forms and records in spite of years of assiduous collecting on the 

 part of numerous workers. 



The life history has been followed for but a short time, but 

 this is sufficient to indicate its general course. The insect occurs 

 either on the bark or on the leaves, probably passing the winter 

 on the former and then going out to the leaves. The presence of 

 adult males and females, mingled with all the immature stages, 

 on leaves scarcely a month old indicates that the life cycle is quite 

 short. The immature stages are attached solely by the beak 

 and are entirely exposed either upon the under side of the leaves 

 or upon the bark. The adult females seek the protection of bark 

 scales when present but may form their ovisacs in the open, some- 

 times remaining even partially within the exuvium of the pre- 

 ceding stage although they are quite active. The males are very 

 active and have been observed apparently attempting to copulate 

 with females that were still in the appendageless state. 



SOME SENSORY STRUCTURES IN THE APHIDID^. 



BY A. C. BAKER, WASHINGTON, D.C. 



During the writer's studies on aphids he has had occasion 



to notice certain sensory s^tructures on the wings and legs of these 



insects. These structures vary in the different groups, and since 



scarcely any references to them appear in the literature of the family 



the writer here records some of his observations. The pores on 



the legs are recorded in technical descriptions of species of Chermes, 



but those present on the legs of insects in other genera and on the 



wings appear not to be referred to in descriptions. Vickery* has 



mentioned the presence of pores on the legs. No experiments 



*Rept. of State Ent. of Minn., 1907-08, p. 178. ~ 



November, 1917 



