ONTOGENY OF ADULT COLOR PATTERNS. 1 55 



adult color areas is delineated upon the elytron by a yellowish-brown deposit 

 of pigment (fig. 3). The stages in development shown in figs. 1 to 3 are passed 

 through rapidly, not more than forty-five minutes being required ordinarily 

 for their completion, and frequently much less time than this ; but after the 

 color pattern is fully blocked out development proceeds much more slowly, 

 many hours and often days being consumed in its completion. After the 

 color pattern has been outlined the remainder of the developmental process 

 consists in the gradual increase in the depth of color, which is simply the 

 deposition of more and more dense azo pigments. In figs. 4, 5, and 6 are 

 shown stages in this process as they appear from the surface. 



When the elytral stripes have attained a fairly dark color (fig. 6), there 

 appears a faint metallic green, which becomes more intense after the beetle 

 has emerged from the ground and begun to feed. As the beetle leaves the 

 pupal cell with its elytral coloration in about the condition shown in figs. 5 or 

 6, it is necessary that a part of the development should go on after it has 

 emerged and begun to feed. Thus the ontogeny of its coloration is distributed 

 over a considerable period of time. 



In allied species, as, for example, in multitccniata, there are found stages 

 in color development of a similar nature, which differ only slightly in detail 

 from those shown in undecimlineata. These are the periods of the demarka- 

 tion of the color pattern and of the intensification of the cuticula color. In 

 multitccniata, however, the ground color changes as development proceeds, 

 beginning with the pale yellow-white and ending with the full yellow of the 

 adult at sexual maturity. These color changes go on independently of the 

 cuticula colors, as they are due to the development of the lipochromes in the 

 hypodermal cells. 



Likewise, in rubicunda, stages in the development of the cuticula colors are 

 found which are like those in undecimlineata (pi. 19, figs. 19 to 24). The 

 changes in the hypodermal color are greater and more rapid, however, than 

 in either of the preceding species, beginning with the same pale yellow-white 

 (fig. 21), orange-yellow, orange-red (fig. 22), red (fig. 23), and finally 

 becoming the bright red of the mature beetle shown in fig. 24. 



These three species, undecimlineata, multitccniata, and rubicunda, are all 

 closely related members of the lineata group and might naturally be expected 

 to show similar stages in ontogeny. Other members of the genus also present 

 stages in development which are of interest; of these some are figured on 

 plate 19. 



In L. dilecta the development of the elytral coloration is shown in figs. 7 to 

 12, plate 19. The initial stage (fig. 7) differs in no respect from the cor- 

 responding one in the species of the lineata group, the beginnings of colora- 

 tion observed here being in the proximal portion of the costal and subcostal 

 spaces. In succeeding stages color spreads from these regions distally and 



