124 
Psyche 
[March 
Table 1. The annual emergence periods for S. scmicircularis 
1st day of Total Emergence Days until 
Location 
Year 
emergence 
adults 
Total days 
50% emergence 
Pond Nine 
1968 
15 July 
543 
14 
3 
1969 
7 July 
166 
15 
3 
Irwin Pond S. 
1971 
3 July 
1528 
21 
6 
away from the ponds as teneral adults (maiden flight). At Pond 
Nine, emergence began on 15 July 1968, 7 July 1969, and 6 July 
1970. At Irwin Pond South, slightly lower in altitude and more 
sheltered by spruce-fir, emergence began slightly earlier — 30 June 
1970, 3 July 1971, and 27 June 1972. 
The total period during which emergence occurs each year is short 
(Table 1). The total annual production of adults occurs over an 
average of 16 days during which 50% of the adults emerge within 
the first three to six days. The 1969 emergence curve (Fig. 2) 
demonstrates a typical, highly synchronized pattern. The 1968 curve 
(Fig. 3) shows the effect of stormy weather and low temperatures 
on 17 and 18 July which delayed the emergence of some of the larvae 
and extended the emergence period. No secondary peak of emer- 
gence was ever observed later in either season. 
The distance flown during the initial flight of the teneral adults is 
unknown. However, they remain away from the ponds, presumably 
in the forest near the ponds or at lower altitudes, for one to two 
weeks. In 1968, the first tenerals left Pond Nine on 15 July and 
the first mature males were observed patrolling the edges of the pond 
on 22 July — 7 days later. By this time, 95% of the adults had 
emerged and flown away (Fig. 3). In 1969, the first tenerals left on 
7 July and the first patrolling male was sighted on 22 July - — 2 
days after the last teneral adult had flown (Fig. 2). These mature 
adults are individuals which emerged at the beginning of the emer- 
gence period, have matured, and returned to the pond for mating. 
Teneral adults and reproductively mature adults are considered here 
to be all part of the same emerging population. They are just tem- 
porally separated. On two occasions mature males were observed 
patrolling a pond when a newly emerged teneral flew up from the 
sedges on its maiden flight. On both occasions, the mature male 
harassed and tried to couple with the soft teneral before the latter 
could leave the pond. One of the tenerals was probably injured by 
