REVISION MALACOSOMA HUBNER IN NORTH AMERICA 153 



ADULT FEMALES (figs. 197-202).— Color varying from yellowish 

 to orange-brown to yellowish gray-brown. Lines on forewings appear 

 light or dark, or dark bordered by light, depending on the amount of 

 contrast presented by the ground color. Outer line with or without 

 small indentations along some veins. Median area usually somewhat 

 darker than inner and outer areas. Hindwing usually darker than 

 forewing, about same color as darker areas of forewing. Lower surface 

 of both forewings and hindwings about the same color as upper 

 surface of hindwing, with a single contrasting line which often divides 

 both forewings and hindwings into a darker inner region and a lighter 

 outer region. 



ADULT DIAGNOSIS.— Females may rarely be confused with female 

 M. disstria, but both males and females are easily distinguished from 

 disstria (page 86) and constrictum (page 94) by characters given for those 

 species in the adult diagnoses. The distribution of Malacosoma amer- 

 icanum adjoins that of c. pluviale along the eastern United States- 

 Canadian border, but both male and female americanum can be positively 

 separated from c. pluviale by the characters given for americanum in 

 the adult diagnosis (page 112). 



Neither males nor females can be positively identified to subspecies 

 without locality data since some similarly colored specimens can be 

 found throughout much of the range of M. calif or nicum. The subspecies 

 is recognized mainly on the basis of the larval color pattern. In the 

 Canadian prairie provinces, however, where the distributions of 

 c. pluviale and M. calijornicum lutescens adjoin, the majority of the male 

 c. pluviale have the points of the accessory claspers closer together as in 

 figure 23 than do male c. lutescens (fig. 24), but intermediates also are 

 found. Also, the outer line on male c. lutescens is often more curved 

 toward the tip of the wing at the costal margin as in figures 210 or 

 221 than on c. pluviale (figs. 191-196). Female c. pluviale often have the 

 dorsal lobe of the ovipositor reduced as in figure 98, and female 

 c. lutescens frequently have a more distinct dorsal lobe similar to figure 

 100. Intermediates similar to figure 101 may be found in both 

 subspecies. 



MATURE LARVAE (figs. 370-372).— Head motded blue and 

 black, sparsely covered with fine yellow-orange setae, Middorsal area 

 of body varying combinations of orange and black, but the black 

 usually visible only as a border of the broken middorsal stripe formed 

 by a series of elongate, blue-white, somewhat pointed dashes, one per 

 segment. Addorsal area predominantly yellow to yellow-orange with 

 some fine irregular black markings on most specimens. Area around 

 setal group Dl black and extends ventrally to setal group SD to form 

 the vertical black bar. Vertical black bar usually with adjoining irreg- 



