274 



KELLOGG AND BELL 



green with yellowish to bluish tinge, and the large conspicuous 

 dorsal spots, six on each elytron, are pure black. 



A lot of 906 individuals, 450 taken October 8, 1901, in a chry- 

 santhemum garden on the Stanford University campus, and the 

 others taken as six small lots from various other places on the 

 campus the same month, were examined and classified on the 

 basis of the obvious variations in the dorsal color pattern caused 

 by the coalescence of various pairs of the large spots. The 

 classes and frequencies are as follows : 



Fig. 50. Diagram showing vars. in eljtral pattern of the flower beetle, 

 Diabrotica soror. 



Class A: 313 individuals have all the spots separate (fig. 50, 

 A) ; this is the condition described for the species and assigned 

 to it in entomological text-books. Class B : 32 individuals with 

 the spots of the middle pair on left elytron conlluent (fig. 50, B^. 

 Class C : 60 individuals with the spots of the middle pair on the 

 right elytron confluent (fig. 50, C). Class D : 396 individuals 

 with the spots of the middle pair on each elytron confluent (the 

 mode, fig. 50, B and C). Class E : 14 individuals with the spots 

 of the posterior pair on tlie left elytron confluent {^\^' 50, D). 

 Class F: 17 individuals with the spots of the posterior pair on 

 the right elytron confluent (fig. 50, E). Class G : 45 individuals 

 with the spots of the posterior pair on each elytron confluent 

 (fig. 50, D and E). Class H : 28 individuals with the spots on 



