Kinsey: Studies of Cynipidse 



141 



observation of Biorhiza forticornis (which is wingless, aga- 

 mic, coming from terminal twig galls on Q. alba) ovipositing 

 in December at the roots of Q. alba. I have observed galls of 

 Trigonasins radicola on the roots of trees w^hich bore old galls 

 of forticornis, and recently Weld (Proc. U. S. Nat. Mus., LIX, 

 pp. 203-204) notes thirty-six instances of coincidence of the 

 two galls on trees of Q. alba. There is considerable circum- 

 stantial evidence, then, of the cyclic alternation of Biorhiza 

 forticGi-nis and Tngo}iaspis radicola. In the paper above 

 mentioned I further described a March brood of forticornis, 

 obtained from the same galls as the December brood, oviposit- 

 ing in the terminal buds of the tree; no galls were obtained 

 from these buds in the experiments. Is it possible that the 

 o)'}iata gall (or more probably a similar variety on Q. alba) is 

 the bud gall from eggs of the March brood of forticornis^ 

 Are there two interlocking cycles in the life of this species? 

 What is the solution of the heredity questions presented? Such 

 are the alluring problems to be solved only after the cycle has 

 been experimentally investigated. 



