7o 



VARIATION IN LEPTINOTARSA. 



single lots of variates show deviation from these species modes and values, 

 the result of place variation, a phenomenon which will be considered later. 

 In the individual variation of the color pattern of the pronotum two facts 

 appear first, that the variations, while numerous, are not promiscuous, but 

 in definitely directed lines; second, that the species tend to segregate their 

 variations about modes arranged along the chief directions of individual 

 variation. 



Variation in the color of the pronotum in the dilecta group. The pronotum 

 in this group has a uniformly colored surface, which, however, shows in 

 some species variations of interest, especially in the intensity of its metal- 

 licism. Thus, in the series of species L. calceata, L. dilecta, and L. lineolata 

 there are variations in the color of the pronotum from reddish-brown to 

 dark metallic green. The range of color is divided into six classes, as 

 follows: (i) reddish-brown; (2) dark reddish-brown; (3) dark reddish- 

 brown with a greenish sheen ; (4) light metallic greenish-red ; (5) bright 

 metallic-green, and (6) dark metallic-green. In table 15 is given the fre- 

 quency of the variations seen in the different species. 



Table 15. Variation in the color of the pronotum 

 L. dilecta, and L. lineolata. 



in L. calceata, 



L. calceata: N. = 50 individuals. Mean of classes = 4.78. 

 L. dilecta : N. = 300 individuals. Mean of classes = 4. 85. 

 L. lineolata : N. = 300 individuals. Mean of classes = 3.89. 



I have not been able to procure enough material of the other species of 

 this group to give satisfactory seriations or data of color variation. In the 

 three species seriated above the variations are plainly limited to very narrow 

 lines ; one series of color changes reddish-brown to metallic-green. These 

 are the only variations known. All three species show a mode on class 5, 

 bright metallic-green, although the range of variation is greatest in lineolata 

 and least in calceata. 



Variation i?i the color of the pronotum oj the haldcmani group. None of the 

 species of this group possess color patterns, and the only variations are those 

 of intensity of color. The pronotum of L. dahlbomi, the most widely ranging 



