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Psyche 
[Vol. 90 
containing the female, she deposited a clear droplet from her genital 
area on the bark. The droplet was absorbed rapidly. The male was 
highly active and quickly found the female, who was still in the area 
where she deposited the droplet, and mated with her. In another 
encounter, the female deposited a droplet about 3 minutes after a 
failed courtship attempt. This pair mated eventually. Another 
female intermittently dragged the tip of her abdomen over the sub- 
strate after the male was introduced into her vial. In two encounters, 
each involving a male and female from a Lake of the Woods culture, 
two from a Lake Dawson culture, and one from a Salt Fork culture, 
the male persistently courted a particular place on the female’s sub- 
strate, even though she was not nearby. Eventually, after about 10 
minutes, males stopped courting these areas. 
I have not observed females of T. castum or T. merum depositing 
any type of droplet in the above manner, or observed males courting 
places on a substrate bearing females of T. castum or T. merum. 
In the orientation experiment, it was important to use freshly 
killed females because after about 5 minutes they lost attractiveness 
to males. Anesthetizing females with ether (N = 3) or carbon dioxide 
(from dry ice) (N = 3) caused an immediate loss of interest by males. 
From the evidence cited above it appears the females of T. alex- 
anderae produce a pheromone that attracts males. It appeared to be 
highly volatile; a loss of mating receptivity in a female was almost 
immediately evident, as indicated by the lack of attractiveness to 
males. 
The area around a female in which the pheromone was effective in 
attracting males was rather small, having a radius of about 1 cm. 1 
determined this by placing individual receptive females (N = 10) in 
uncovered petri dishes (standard size), then introducing sexually 
active males. 
Discussion 
Mating behavior in T. alexanderae followed a pattern outlined by 
Pearman (1928) for “winged Psocids.” This courtship pattern, which 
has since been categorized (Badonnel 1951) and further documented 
(Klier 1956), is the one found in most species of Psocoptera that 
have been studied. This pattern differs from those in other species in 
two details: males do not run over the dorsum of females prior to 
mounting, and the duration of copulation is relatively long. 
