1974] 
Cooper — Boreus 
93 
Discussion of Mating 
The events just described are different in a number of significant 
features from those in the matings of B. hyemalis , B. westwoodi and 
B. brumalis, which are alike. Once a female of those species has 
been seized by a male, it ordinarily becomes passive (but wot always, 
see Syms 1934, Aubrook 1939, Sauer 1966, Crampton 1940). The 
rested male then grips the female across the midbody with his wings 
(as does B. notoperates) , and with them and his gonostyles works 
her body over his dorsum so that it is axially symmetrical and paral- 
lel to his own. The gonapophyses are then pried down and inserted 
into the subepandrial pocket, the wing-hold is released and the female 
rocks back until perpendicular to the male. Intromission very likely 
occurs at this point, as it does in B. notoperates. The relative station 
of the two sexes just prior to intromission, or the “pose” (Lamb 
1922), in all four species is truly a “female vertical pose” with (pre- 
sumably) an inverse correlation of the genital conduits of the two 
sexes. 6 
Now Lamb (1922) used “vertical” as a contrasting term to 
“linear” (or tail to tail) to denote arrangements of partners in which 
one partner is above the other. In the overwhelming majority of such 
cases, the body of the upper insect lies more or less parallel to that 
of its partner. Consequently I shall call the pose common to the 
four Boreus a “female perpendicular pose” to distinguish it. The 
final copulatory attitude of B. notoperates does not depart from the 
pose; accordingly it is a “female perpendicular position” (fig. iA).. 
In contrast, B. hyemalis, B. westwoodi , B. brumalis, B. calif ornicus 
(=var. fuscus Carpenter?) (Cockle 1908, 1914), B. nivoriundus 
Fitch (Carpenter 1936; Cooper, unpubl.), B. unicolor Hine (Byers 
1954) and B. vlasovi Martynova (Vlasov 1950), namely in all other 
species for which the copulatory position has been recorded, the final 
attitude differs from the pose, being a female vertical position. 7 
6 On intromission, the apparent dorsal wall of the aedeagus of Boreus lies 
in contact with the ventral wall of the common oviduct, hence in “inverse 
correlation”, which is unusual (fig. 1C). In most insects correlation is 
“direct”, or symmetrical, for contact is dorsal-dorsal and ventral-ventral ; 
in many insects having a vertical position, direct correlation is brought 
about by rotation of the male genital tract (see Lamb 1922). 
Tor original drawings, or photographs (reference in boldface), of copu- 
lating pairs in their final female vertical position, see: for B. hyemalis 
fig. 3, pi. 8, Withycombe (1922), fig. 1, Steiner (1937), fig. 7, Striibing 
(1958) ; for B. westwoodi, fig. 5, pi. 3, Brauer (1855), fig. 2, Sauer (1966) ; 
for B. brumalis, fig. 9, Cooper (1940), fig. 1, Crampton (1940). 
