Vol. XXvi] ENTOMOLOGICAL NK\VS. 



These Iowa specimens of Chrysobothris average a little lar- 

 ger and the elytral f oveae are more distinctly bronzed or metal- 

 lic than those from New York and Massachusetts in Profes- 

 sor H. F. Wickham's collection. 



There are, perhaps, two things of particular interest in re- 

 gard to this experiment: first, the great number of Lepturges 

 querci secured from a comparatively small number of twigs 

 indicates a very high degree of infestation ; second, in the 

 rather limited number of Chrysobothris aznrea obtained the 

 males averaged a little earlier in emergence than the females. 

 This is, however, not an unusual occurrence among other spe- 

 cies of Coleoptera. I believe also that Wistaria chinensis has 

 not been recorded as a host plant for either of these species 

 of beetles. 



I am indebted to Professor H. F. Wickham for the deter- 

 mination of the Chrysobothris and to Professor R. B. Wylie 

 for the determination of the Wistaria. 



Fragments on North American Insects VIII. 



By A. A. GIRAULT, U. S. National Museum, Washington, D. C. 



Difference in Habit as a Basis for Specific Differentiation. 

 I have noticed a tendency lately with entomologists and 

 others to make a difference iu habit coequal with a difference 

 in structure and coloration as regards species. My attention 

 was drawn again to this matter by casually noticing that Pierce, 

 Cushman, Hood and Hunter (Bull. No. 100, Bureau of Ento- 

 mology, U. S. Department of Agriculture, Washington, D. C., 

 p. 53, footnote. 1912) separate a braconid into two species 

 Microbracon dorsata and mcllitor of Say on the basis of a 

 difference in social habit. They admit the two are alike struc- 

 turally ; in habit they differ in that mcllitor is parasitic upon 

 coleopterous larvae and solitary, while dorsata is parasitic 

 upon lepidopterous larvae and </re</arioits. To my mind the 

 separation has no reason for being. From a practical stand- 

 point, suppose that an exploring party captured a number ot 

 Braconidae and turned them over to some Hymenopterologisl 



