158 UNITED STATES NATIONAL MUSEUM BULLETIN 2 76 



females, but whatever the reason may be, this is certainly an unusual 

 behavior pattern that is worthy of further investigation.^'' 



The question arises as to whether these bog populations should be 

 recognized. To describe them as a new species seems to be out of the 

 question on the basis of information currently available. In British 

 Columbia there is absolutely no information on their relationships 

 with neighboring populations of M. californicum pluviale to the south, 

 west, and north, since no adjoining populations have been reported to 

 date. To the east, the situation is no better known, since it is not even 

 known whether populations of "normal" pluviale are present between 

 the bog populations and the prairie subspecies M. californicum lutescens. 

 In 1 960 one of the authors (FWS) was unable to find any Malacosoma 

 in this area to the east, but was able to attempt crossing specimens of 

 the bog populations with those of M. californicum lutescens from Bcau- 

 vallon and Derwent, Alberta, about 100 miles east of Edmonton (see 

 table 2, R27, R28, R35, R36, and the discussion of "The pluviale- 

 lutescens relationship"). In the Fj generation, fertility and viability 

 were "normal" for the cross of female lutescens X males of the bog 

 population, but the reciprocal cross of male lutescens X females of the 

 bog population showed reduced fertility (page 60). 



The only chance to cross individuals of the bog population with 

 individuals of what has been regarded as typical pluviale was in cross 

 R31 of table 2, in which males of typical pluviale (Coll. No. 122C, 

 Eugene, Ore.) were crossed with females of the bog population (Coll. 

 No. 180). The Fj showed no reduced fertility or viability, and in fact, 

 R3 1 was one of the most successful of all the Fx egg masses which were 

 reared. This cross is of the same kind (males of some population X 

 females of the bog population) as that which showed reduced fertility 

 between lutescens and the bog population (R27 and R36), Although 

 only a single egg mass was reared and the reciprocal cross was not 

 attempted due to timing difficulties, there is no indication of any 

 genetic barrier bet^^veen the bog population and "normal" pluviale 

 similar to that which appears to be present between the bog populations 

 and at least some of the lutescens populations. Of course, this kind of 

 information can only demonstrate whether or not two populations 

 are able to interbreed successfully; whether they do or not is an entirely 

 different question, and can only be determined by field studies in areas 

 where the populations in question occur together. Since at present 

 there is no known area where ^'normal" pluviale and the bog populations 

 are found together, evidence of reproductive isolation in the field is 

 entirely lacking. On the basis of available data, the bog populations of 



10 Since this was written, very similar bog populations have been discovered in the 

 Upper Peninsula of Michigan on Belula pumila, a very close relative of B. glandulosa. 



