^^ IT/ 



130 EVOLUTION OF COLOR PATTERN IN LITIIOCOLLETIS. 



The adult coloration appears to be attained several hours previous to 

 emergence. At this time the markings are plainly visible through the pupal 

 envelope. The bluish iridescence in the cilia is now well developed. Obviously 

 this is one of the last characters to appear ontogenetically. 



Lithocolletis ostryaefoliella Clem. 



This species (Fig. 23, PL III) possesses an apical dot in its typical condition, 

 composed of small black or blackish brown scales arranged in an almost circular 

 shape over the tip of the wing. 



In the youngest specimen examined, the wings were dissected out at a period 

 when they were losing their whitish appearance and becoming faintly banded. 

 i,ii,m j^ V ,., The last four bands are straight and placed transversely 



on the wing, leaving colorless bands between them. The 



basal portion of the wing is exceedingly pale, and the 



ground color is scarcely discernible on the otherwise 



Fig. 14. Early stage in the colorlcss wiug. The Configuration of the color areas is 



development of color in the wing ^^^^ ^^^ ^^^^ ^^ -^ ^^^ ^^^^^ there being the Same 



of L. ostrycefokeUa. ' ^ 



outward angulation of Band III, internal to the first 

 pair of white streaks. A stripe along the middle of the wing and a white spot 

 on the dorsal margin remain colorless and mark the position of the basal streak 

 and the white dorsal spot in the adult. 



At a slightly later stage, the markings just referred to have become a little 

 more distinct; the color is still a very pale straw {Fig. IJj). The extreme base of 

 the wing, while very pale, is still sufficiently contrasted with the unpigmented 

 areas to show the outline of the basal streak defined for its whole length. On 

 the dorsal edge, a pale shade broadest on the dorsal margin reaches two-thirds 

 of the way across to the basal streak. On the basal side of this spot, the ground 

 color seems a little deeper. Band III, although much angulated outwardly, is 

 not yet connected in the middle of the wing with Band 



. . . i,7rjrr TV y VT ,,^^ 



IV; thus the first pair of white streaks are still con- ^^ 



nected and form an angulated fascia, broadest at its ^^ 



extremities. Bands IV, V, Viand VII remain entirely 



separate and retain their primitive straight edges, with Fig. is. Later stage in the 



the exception of the inner edge of Band IV which has "p^^^^* of color in the wing 



^ ^ 01 L. ostrycefoLieila. 



been somewhat produced toward the base at its ex- 

 tremities. Band III and Band VII are possibly a shade darker than the other 

 portions of the wing; the scales attached around the apex projecting into the 

 cilia are, however, paler and concolorous with Bands IV, V and VL 



The ground color continues to darken, reaching its adult condition at a 

 relatively earher stage than is the case in L. cratcegella. At the same time {Fig. 

 15), the pale yellow spreads onto places originally unpigmented; thus the bands 

 become connected by a paler yellow shade, so that the white fasciae are trans- 

 formed into pairs of opposite narrow white streaks. At this stage in the develop- 



