10 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



(Rynchospora) in south Texas. B. albescens LeConte breeds in 

 the stems of Cyperus virens at Victoria. 



Trichobaris compacta breeds in pods of Datura stramonium 

 at Dallas. It pupates in the pods. The genus Trichobaris is 

 confined to solanaceous plants but the species usually breed 

 in the stems. 



Rhinoncus pyrrhopus breeds in the stems of Polygonum pennsyl- 

 vanicum. 



Baris cuneipennis Casey breeds under the bark of the roots of 

 Gaillardia pulchella, Helenium tenuifolium and H. microcephalum 

 in Texas. Numerous species of this genus have been bred by the 

 writer and all breed under the bark of the roots. 



Orthoris cylindrifer Casey breeds in the stems and root crown of 

 Mentzelia oligosperma at Dallas. The entire genus is confined to 

 plants of the genus Mentzelia. 



Nyssonotus seriatus Casej^ breeds in the dry stems of Agave 

 lecheguilla following attack by Peltophorus polymitus another 

 weevil, in south Texas. 



Rhodobaenus 13-punctatus breeds in the stems of Xanthium 

 commune, Heliantims, Ambrosia trifida and Polymnia canadensis. 



SOME INTERMEDIATES IN THE APHIDIDAE. 



(Hemiptera.) 

 BY A. C. BAKER AND W. F. TURNER. 



In a recent paper 1 the authors discussed the intermediates so 

 far known to occur in the Aphididae and expressed the opinion 

 that they are of normal occurrence in the family and indicate the 

 method by which the apterous form has been derived. Inter- 

 mediates of several other species can now be added to the list and 

 it seems worth while to consider a few other points also. 



If the family is at present in an unstable condition, and the 

 alate forms are now being eliminated, two things would be ex- 

 pected, first, we would expect the primitive aphids to show a very 

 high percentage of alate individuals and, secondly, we might ex- 

 pect to find alate examples of all the distinct forms of the family. 



If a random collection of aphids were made today in America 

 a very high percentage of the specimens collected would be apter- 

 ous individuals and alate aphids would be few comparatively. 

 It is interesting to note then that among the tertiary aphids so far 

 as we know the American forms only one specimen is apterous. 

 This might possibly indicate a preponderance of alate forms at 

 the time these deposits were laid down. 



1 Proc. Ent. Soc. Wash., vol. xvu, 1915, p. 42. 



