144 
Psyche 
[December 
COURTING AND MATING PERFORMANCES OF AN 
ASILID FLY (HETEROPOGON LAE TVS) 
On September 13, 1932, in a mesquite pasture near Spur, 
Texas, the small robber-fly, Heteropogon lautus Loew, was 
very abundant, numbers perching on the tips of dead twigs 
of the mesquite five or six feet from the ground and on the 
barbs of a wire fence enclosing the pasture. They be- 
trayed interest in passing objects by quick movements of 
their heads, but were not wary and could easily be cap- 
tured by hand. Several were seen feeding on small winged 
formicids. But what attracted our attention particularly 
(Mr. W. C. O’Dowd of the Texas Agricultural Experiment 
Station was with me and together we watched the 
phenomenon) were their peculiar actions which observa- 
tion proved to be courtship and mating. Hovering in front 
of the female at a distance of about an inch, the male would 
poise, oscillating somewhat from side to side and waving 
his front tarsi, which are clothed with appressed white 
hairs, toward the female. He might continue in this posi- 
tion for a period of thirty seconds or more. Often the fe- 
male appeared to ignore his presence; at other times she 
watched him eagerly, waving her front tarsi in return and 
spasmodically half-raising and lowering her wings. The 
male would then fly over, turn in midair and alight in back 
of the female, coition then taking place. At other times 
males were seen to alight in back of the females and press 
their mystacal bristles against the spines of the cerci sur- 
mounting the ovipositor. At such times, the female would 
half-raise and lower her wings as described before. Fre- 
quently the male would then spring to his hovering posi- 
tion in front of the female and the tarsi waving would begin 
again. In one instance, an additional male was noted hover- 
ing in front of a pair in copulation. 
Stanley W. Bromley. 
