100 UNITED STATES NATIONAL MUSEUM BULLETIN 2 76 



of M. calijornicum, such as figure 359. However, M. californicum call- 

 fornicum never has the hourglass-shaped blotches which are flanked 

 by the round black spots, nor does it have the conspicuously tufted 

 dorsal secondary setae, or the long, blackish primary dorsal setae. 

 In the past constridum austrinum has undoubtedly been confused with 

 californicum or californicum californicum because of the superficial sim- 

 ilarities in the larvae, and also because very dark adult males of 

 californicum and californicum californicum are vaguely similar to some 

 specimens of constridum austrinum. They are easily separated, however, 

 from all populations of M. californicum by the distinctive shape of 

 the male genitalia, especially the shape of the eighth sternite (compare 

 fig. 38 with figs. 44—51 and see the description of the terminalia of 

 M. constrictum, page 93). This confusion of larvae and adults of con- 

 stridum austrinum with those of californicum and californicum californicum 

 has resulted in M. californicum commonly being reported from southern 

 California where the occurrence of any form except M. californicum 

 fragile is questionable. See the "distribution" under M. californicum 

 for a discussion of this (page 127). 



EGG MASSES, TENTS, AND COCOONS.— The same as those of 

 M. constrictum constrictum (page 89). 



FOOD PLANTS. — With one exception, tgg masses were not found 

 on plants other than oaks in 1960 or 1961. In this case, a few egg masses 

 were found on Ceanothus twigs, but these twigs were intertwined with 

 those of Quercus dumosa, on which many egg masses were found. No 

 egg masses were found on Ceanothus which was not growing with 

 Quercus dumosa. Caterpillars will eat other plants, and some were 

 reared from eggs through the third instar on Rosa before they succumbed 

 to disease. Oviposition does not normally take place on plants other 

 than oaks, however. Egg masses were found on Q. dumosa, Q. agrifolia, 

 and Q. engelmanii in 1960 and 1961. It should occur on all other species 

 of oaks which grow in southern California and Baja California. 



TYPE. — Holotype, a not fully mature, female, last instar larva 

 collected as an early instar larva and reared to the last instar. Color 

 pattern the same as described above, but the grays and blacks appear 

 more brownish when preserved in alcohol. Length, 45 mm., killed in 

 KAA solution, and preserved in 95-percent ethyl alcohol. United 

 States National Museum Type No. 67665. 



TYPE LOCALITY.— One quarter mile E. of Santa Ysabel, San 

 Diego Co., Calif., Elevation 3000 ft., collected 3 April 1960 by F. W. 

 Stehr, Collection No. 26. Host: Quercus dumosa. 



DISTRIBUTION. — M. constrictum austrinum has been collected in 

 the larval stage only at Guatay and Santa Ysabel in San Diego County, 

 and at Temecula in Riverside County, Calif. Larvae collected at 



