108 UNITED STATES NATIONAL MUSEUM BULLETIN 2 76 



dead twigs, indicating that this may be a rather common habit (see 

 discussion of this above). 



Genitalia of lectotype in micro vial labeled : Lectotype, Malacosoma 

 tigris (Dyar), male genitalia, F. W. Stehr 1963, The lectotype is paler 

 than most tigris, but it may be faded. The accessory claspers of the 

 lectotype differ from the majority of males in being evenly pointed 

 instead of jagged as in figure 14. 



TYPE LOCALITY. — It is impossible to say with certainty which 

 locality of several mentioned in his notebook the specimens of the 

 United States National Museum came from, but since the original 

 description mentions the Platte Canyon, near Denver, Colorado, first, 

 this is selected as the type locality. 



PAR ALECTOTYPES.— Eight male and 7 female adults bearing 

 "Dyar and Caudell" labels and labels with numbers ranging from 

 16927 to 17154, all of which are equal to 16926 according to Dyar's 

 notebook. Also 3 c^^ masses (2 on 1 twig), 10 inflated larvae and 3 

 cocoons (on 1 pin) bearing "Dyar and Caudell" labels of which 1 egg 

 mass, 1 larva, and the cocoons have a label saying "938," referring to 

 Dyar's brown notebook No. 938. There are also additional larvae and 

 possibly other life stages in the United States National Museum which 

 were not labeled as paralectotypes. 



DISTRIBUTION (fig. \).—M. tigris occurs in the southern Great 

 Plains, the southern Rocky Mountains, the Southwest, and Mexico. 

 In Mexico it probably occurs wherever oaks grow and the climate is 

 suitable for breaking its diapause. 



The most southern record for any species of Malacosoma in North 

 America is for 3 male tigris from San Cristobal las Casas, Chiapas, 

 Mexico, by C. C. Hoffman, August 1940. There are mountains above 

 9,000 feet in Chiapas v/hich apparently enable tigris to break diapause 

 that far south (Chiapas recoi-ds not plotted in fig. 1). 



It should also be found in Guatemala where elevations exceed 1 0,000 

 feet in several places. However, there is little above 6,500 feet in Hon- 

 duras and El Salvador, and little above 4,000 feet in Nicaragua, so its 

 southward distribution may be stopped by the inability to break dia- 

 pause in these areas. It could survive in Costa Rica since there are 

 many mountains above 6,500 feet, with some volcanic peaks reaching 

 11,000 and 12,000 feet. Most of Panama is below 3,500 feet except in 

 the west near Costa Rica, so it probably could not break diapause in 

 Panama either. There are no authentic records of Malacosoma from 

 South America, but they could certainly break diapause all along the 

 Andes if they could get there. 



M. tigris's, westward distribution seems to be limited by the lack of 

 oaks in the Mojave Desert and the Great Basin. It seems to be adapted 



