1983] 
Betz — Biology of Trichaclenotecnum 
113 
A female manipulated a spermatophore between her paraprocts 
and valvulae. These movements were accomplished by a rhythmical, 
medial flexion of the terminalia. Contractions were spaced about 
1-2 seconds apart, and each contraction lasted about 1-2 seconds. 
The epiproct was less active in this respect; it was flexed once about 
every 30 seconds. Epiproctal flexion probably forced the contents of 
a spermatophore into a female’s genital area. The abdominal con- 
tractions were pronounced for about the first 4-5 minutes after 
copulation, then slowly decreased in rate and intensity. 
The females I observed (N = 3) required about 10-25 minutes to 
transfer the contents of a spermatophore and discard it. A spermato- 
phore either fell from a female’s genital area when she ran (N = 2), 
or a female dragged the posterior end of her abdomen along the 
substrate for about 1 mm to discard it (N = 1 ). A female sometimes 
intermittently flexed her terminalia after a spermatophore had been 
discarded. 
Evidence for a Sex-attractant Pheromone 
The following observations present evidence indicating that the 
attraction of males to females of T. alexanderae was mediated by a 
pheromone. All females discussed here were unmated, receptive 
females from cultures of all three field localities unless noted 
otherwise. 
Males introduced to bark bearing receptive females often became 
more active than when they were introduced to pieces of bark 
which had no exposure to receptive females. Some males became so 
active they flew across the gap between the pieces of bark before I 
could join these together. A male was usually able to find a receptive 
female, even though she may have remained hidden from his view. 
Additionally, males would court females of T. castum and T. 
merum, two obligatorily thelytokous species of the T. alexanderae 
species complex, if vials containing these females had previously 
contained receptive females of T. alexanderae (Betz 1983a). 
Females of T. alexanderae which had just mated ceased rapidly to 
be a source of attraction to males, although males occasionally tried 
to court females engaged in mating. Teneral females, or females in 
the stage of oviposition, failed to attract males (Betz 1983c). 
In one mating encounter involving a male and female from a Lake 
of the Woods culture, when the male was introduced into a vial 
