1974 ] 
Cooper — Boreus 
87 
agreement. But it has also been claimed, as early as Hardy’s (1848) 
and MacLachlan’s (1868) notes, that the sex ratio of Boreus is 
spanandrous, but only loosely in Marchal’s (1911) sense, namely 
that males regularly make up a minority of the population. Not 
surprisingly, small collections of Boreus may show a predominance 
of one sex. In general, however, collections of two dozen or more 
specimens at a locality, but not made at the season’s close when 
females do tend to predominate, give sex ratios which approximate 
equality, as do those for B. notoperates. There are, however, excep- 
tions. But for none of the following records is there a significant 
departure (namely, P < 0.05) from equality of the sexes: 
1. B. brumalis Fitch 
27 cf c? 
26$$ 
(Hanover, N. H., 
'Cooper, unpubl.) 
2. B. coloradensis Byers 
21 
20 
(Byers 1955) 
3. B. unicolor Hine 
64 
57 
(Chapman 1954) 
4. B. hy emails ( L. ) 
39 
4 i 
(sifting, Druet & Le- 
gros, ex Lestage 1941) 
33 
45 
(table 1, to Dec. 20, 
Strubing 1950) 
103 
no 
(table 4, not text p. 84, 
Strubing 1950) 
19 
1 1 
(Schiirmann, ex Strub- 
ing 1950) 
38 
45 
(pitfall traps, Cotton 
1971) 
5. B. westwoodi Hagen 
60 
64 
(Martynova 1954) 
24 
25 
(Martynova 1954) 
12 
14 
(Martynova 1954) 
6. B. bey-bienkoi Tarb. 
56 
49 
(Tarbinsky i960) 
As exceptions, with probabilities 
< 0.02 
to < 0.00 1 as random 
departures from equality of the sexes, we have: 
7. B. nivoriundus Fitch 
42 cf cf 
23 ?? 
(Hanover, N. H. 
Cooper, unpubl.) 
8. B. hy emails (L.) 
398 
123 
(Steiner 1937) 
9. B. westwoodi Hagen 
97 
67 
(3 collections, data 
homogeneous, Fjellberg 
& Greve 1968) 
Judging by records 1-6, and from the proportions among im- 
mature stages which have been sexed, the records 7-9, all of which 
show a significant preponderance of males, may reflect a tendency for 
