1983] 
Betz — Biology of Trichaclenotecnuni 
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usually held about 90° apart and at about 45° off the substrate at 
rest and also during the search for a female. Directly after contact- 
ing her, a male backed away slightly, then rapidly fanned his wings 
over his body. The wings were fanned at such a rapid rate and at 
such a small angle (never more than 90°) that they became blurred. 
As a male continued to fan his wings, he began to move anteriorly 
along a female’s side, while still remaining perpendicular to her. A 
male continued this motion until he was almost facing a female. 
When this occurred, a male stopped fanning, dropped his wings 
slightly, turned about 180°, and backed underneath a female 
between her legs. The genitalia were apposed in this manner. 
Occasionally a male stopped fanning when he was only laterally 
apposed to a female’s head, then turned about 90°, and tried to back 
under her. Of the 14 mounting attempts I observed progressing 
in this way, only two of them led directly to copulation. Of the failed 
attempts, eight were unsuccessful because males were blocked from 
backing in by females’ legs; in the remaining four attempts, males 
turned around farther than necessary and kept moving backward 
beside the females rather than beneath them. 
When a female remained hidden from a male’s view, he some- 
times approached her directly from the front (N = 3). In two encoun- 
ters, the female assumed the receptive posture (see below) as the 
male fanned his wings. However, both of these males were unable to 
locate the female after they turned around and began to move 
backwards. One of the males approached the female on her left, 
turned counterclockwise about 240°, and finally stopped after mov- 
ing 8 mm away from her. He then tried to mount her end-to-end 
(i.e., facing away from her), but this failed. The pair remained 
motionless in the end-to-end position for about 30 seconds with 
their genitalia nearly touching, then the male courted the female 
from her side and was able to orient himself correctly. 
The male of the third encounter courted frontally, but the female 
turned her body slightly instead of assuming the receptive posture, 
and the male was unable to move far enough backward for their 
genitalia to come together. The courtship did not lead to copulation. 
Most (73.7%) courting attempts were successful on the first try 
(Table 1, A). When an attempted mounting failed, a male and 
female always remained motionless for about 10-30 seconds. After 
this period, if a male and female remained within about 1 cm after 
