REVISION MALACOSOMA HUBNER IN NORTH AMERICA 149 



ADULT FEMALES (fig. 190). — Females are more constant in color 

 than males, usually being fairly light pale yellow with dark lines, but 

 some specimens vary toward the light orange-brown forms of adjoining 

 populations of M. californicum and M. calijornicum pluviale. 



ADULT DIAGNOSIS.— Females are most likely to be confused 

 with female disstria, but both males and females are distinguished 

 easily from disstria (page 86) and constrictum (page 94), the only other 

 species which occur in the same area, by the characters given for those 

 species in the adult diagnoses. Females cannot be separated from those 

 of other nearby populations of M. californicum, but most males can be 

 separated by their dark reddish-brown color with dark lines or the lack 

 of distinctive lines on the forewings. Populations at the distributional 

 edges which do not possess at least 75 percent dark males should be 

 called M. californicum (Packard). 



MATURE LARVAE (fig. 364). — Larvae intergrade completely 

 with adjoining populations at the northern end of the distributional 

 range and as far south on the east side of the Sierra Nevada as the 

 Lake Tahoe area, but it is not known what situation exists along the 

 crest of the Sierra Nevada to the south since it was not possible to 

 collect any specimens there. Head mottled blue and black, sparsely 

 covered with fine yellowish to orange setae. Middorsal area various 

 combinations of black and reddish-orange, but the black may only be 

 visible as a border of the broken stripe formed by a series of elongate, 

 blue-white, somewhat pointed dashes, one per segment. Addorsal 

 area a mixture of black and somewhat reddish-orange, irregular, 

 longitudinal markings, but usually with the orange predominating. 

 Rarely, this area may be nearly black. Area around setal group Dl 

 black and extending ventrally to setal group SD to form the vertical 

 black bar which usually has weaker black markings on both sides in 

 the subdorsal area that merge with it to form a rather distinct torso 

 mark (figs. 7 and 9). Anterior and posterior subdorsal spots blue, 

 usually not prominent; remainder of subdorsal area mixed orange and 

 black like addorsal area. Subdorsal line orange, irregular, and speckled 

 with fine black markings. Supraspiracular and subspiracular areas a 

 mixture of irregular, fine orange, blue, black and gray markings, 

 generally appearing more orange than blue or gray, but occasionally 

 quite blue or gray when the addorsal and subdorsal orange is reduced. 

 Ventral area gray-white, mottled with black, and with a black area 

 crossing the middle of each segment. Primary and secondary dorsal 

 setae orange. Primary and secondary lateral setae usually orange, but 

 sometimes white, especially near the edges of the range where inter- 

 gradation with adjacent populations takes place. Both dorsal and lateral 

 secondary setae rather sparse, short and not noticeably tufted. 



