300 
Psyche 
[September 
opportunity for field studies to turn up this sound is remote or 
fortuitous at best, since the signal is most frequently performed (in 
A. conspersa) during the third and fourth week just before the 
general drop-off in social activity and die-off in the population due 
to predation. Therefore, the age of any population must be considered 
before comparing populations or species in this respect, and caged 
captives or reared populations may be necessary to turn up such 
sounds. 
The close relationship of the Oedipodinae and the Acridinae (Rehn 
and Grant, i960) has significance here. Most of the Acridinae are 
highly specialized for 'emitting solitary stridulations (buzzes) as the 
sole, long distance male-female signalling device and usually the 
female is unseen. Many of the Oedipodinae, on the other hand, 
utilize spontaneous flight crepitation, instead, for distance commu- 
nication and femoral-tegminal stridulations are less specialized and 
distinct interspecifically. 
Courtship . 
This sequence is often broken into two parts, one is the approach 
by the male and the other is the pre-mounting cry or Anspringlaut 
(Faber, 1936) produced just before the male “leaps” on the female. 
In A. conspersa the demarcation between the two songs is well 
marked since the approach chirp is unitary and periodically produced 
between or during spurts of running, but the multiple chirp (Fig. 4) 
is given only while the insect is standing still (near the female 
usually) and mounting occurs immediately thereafter unless pre- 
vented by the female’s non-receptive behavior. Otte (1968) has 
observed the same type of demarcation in other Arphia species (and, 
by inference, also in A . conspersa) but feels that the multiple chirp 
is only an intensifier of the unitary sound as the male nears the 
female. 
We are amassing data on males of known adult age in the field 
and in caged populations. It is evident so far that any or all of the 
acoustical signals by the male can be omitted even in successful court- 
ships, and mounting of receptive females can be very casual — 
especially among older individuals. Very little is known about the 
signals of female receptivity, and the observed sexual presentation by 
the female may only be a function of propinquity. Thus far, no 
vestige of stridulation has been observed in females of A. conspersa 
and has rarely been reported for any other species of oedipodine. 
This is despite the fact that many acridine and oedipodine females 
(including A. conspersa) have a well-developed stridulatory appra- 
