Kinsey: Studies of Cyni/pidx 



73 



looked by the approximate taxonomy which fails to distinguish 

 the several varieties concerned! 



Important information as to the age of the species and 

 factors in the origin of species are mentioned in connection 

 with variety lutescens. 



Diplolepis ignota (Osten Sacken) with its varieties occur- 

 ring thruout the eastern part of the United States is so 

 closely related to variabilis that there cannot be found differ- 

 ences in the insects which one could presume are of more than 

 varietal rank. With a single change in regard to the sculp- 

 ture of the mesopleuras, the general description of this species 

 will apply to all varieties of ignota. On the other hand, the 

 galls of ignota varieties are covered with a white scurf which 

 the galls of all varieties of variahilis lack, and all of the white- 

 galled varieties occur in the eastern half and all of the brown- 

 galled varieties in the western half of the United States. This 

 indicates closer affinities within each group than between the 

 groups. One must choose between considering the groups as 

 species and over-emphasizing their distinctness ; and consid- 

 ering it a single species involved and attempting to express the 

 groupings of the varieties by a system of quadrinomials, which 

 is objectionable. If we will keep in mind the close relations 

 of the two it may prove most convenient to use two specific 

 names. 



Of 1622 insects which I have bred, 784, or over 48 per cent, 

 are males. I have a relatively small amount of material of 

 ignota, and I had previously believed that the high percentage 

 of males obtained there was abnormal. But it would appear 

 as if these species have a more nearly equal sex ratio than 

 some others of the genus. As with other rose cynipids I have 

 bred, the males appear to emerge earlier than the females, 

 accounting for instance for the 57 per cent males collected at 

 Provo, and the 43 per cent collected at Holly. The insects 

 emerge early in the spring, in late April in the Rocky Moun- 

 tain country, probably earlier or later in regions of earlier or 

 later seasons. I have recounted the life history of ignota 

 (Bull. Amer. Mus. Nat. Hist., XLII, p. 331), and that species 

 in Massachusetts does not have an alternation of generations. 

 The field data for iKtriahilis do not disagree, and it is prob- 

 able that an alternation does not occur for any variety of 

 either group. 



