REVISION MALACOSOMA HUBNER IN NORTH AMERICA 187 



brownish eyes, or were intermediate between the other extreme types. 

 The eye color of pinned specimens which have been examined does not 

 appear to be correlated with overall color, but the colors may have 

 changed after death. Pale yellowish specimens of M. tigris (figs. 171 

 and 172) and M. californicum (figs. 213, 228, 233, 238, 243, and 248) 

 have dark eyes, but the eye color of these was not checked when they 

 were alive. 



Ancona indicated that cocoons subjected to 28° C. produced 

 abundant yellowish moths, but they were not as pale as the typical 

 luteimargo. Some of the palest individuals may be true albinos, but 

 many of them may be the result of temperature effects similar to those 

 suggested by Ancona. Pale yellowish adults similar to those Dyar 

 described as luteimargo were not obtained from any of the collections of 

 M. incurvum reared during this study, and they were not present among 

 museum specimens from areas other than the Mexico City area. 

 Therefore, it seems most likely that the luteimargo type of adult is the 

 phenotypic expression of gene combinations peculiar to the Mexico 

 City area as far as presently known, and whose expression may be 

 influenced by temperature or other factors. None of them appear to be 

 true albinos, since there is some pigment in all of them. For the above 

 reasons luteimargo is regarded as a color phase of M. incurvum aztecum. 



Specimens Examined. — 205 (Museum specimens — 100 males, 50 females, 55 

 larvae, and 5 egg masses). 



Mexico. — distrito federal: City Mexico; Mexico City; Tacubaya; 

 Tacubaya, 653; Xochimilco; S. Angel; TIalpam; San Pedro de los Pinos; 

 Santa Maria, tlaxcala: Huamantla. Veracruz: Jalapa. durango: Du- 

 rango; 10 mi. W. El Salto; 6 mi. W. El Salto. chihuahua. — Chihuahua, no 

 specific locality. — "Mexique"; "Mexico"; "Mex." 



The Palearctic Species and a Brief Comparison with 

 the North American Species 



A few adults and larvae of M. neustrium (L.), M. castrensis (L.), and 

 M. franconicum Esper have been available for study. A detailed study 

 of these species and their variability has not been possible, nor has a 

 complete survey of the extensive European literature on Malacosoma 

 been undertaken. Insuflacient positively identified specimens of a fourth 

 described European species of questionable status, M. alpicola (Staud- 

 inger), were available so it has not been included. It seems to be very 

 close to franconicum, however. Specimens of neustrium and castrensis 

 supposedly collected in North America have been seen among museum 



279-280 — 68 13 



