328 
Psyche 
[September-December 
The side lights were reduced by a rheostat to 60% intensity for the 
present experiment because the greater intensity resulted in compul- 
sive phototropism (in the sense of Verheijen, 1958) and a disturbed 
dorsal light reflex by the insects, effectively inhibiting any social 
interactions. 
Kodak RAR 2485 Instrumentation film (on thin Estar-base) has 
a reversal exposure index (E. I.) of 1600 and a photosensitivity 
rating of 10,000 in response to the activated P 1 1 CRT phosphor 
coating. Eastman-Kodak MS 857 developer minimizes graininess 
if development is forced only one F-stop (to E. I. 3200), comparing 
favorably with Tri-X film of 320 E. I. using standard exposures 
and D-19 developer. With the present system the correct exposure 
for the CRT trace was with the oscillo lens open (F 1.8) and CRT 
beams at full intensity at 0.65 m. For the subjects I had to open 
the front lens ij 4 to 2 F-stops over the reading on the calibrated 
Hycam exposure meter (Pen tax i°/2i°). 
Angles and displacements of moving organs were analyzed on a 
Vanguard motion analyzer (model M16C), and the tapes were 
analyzed with a Kay Electric Co. model 675 audiospectrograph 
(Missilyzer) and a Tektronix model R5030 oscilloscope and C-70 
camera. The secondary emission electron photomicrographs of the 
stridulatory file were produced by a Cambridge scanning electron 
microscope using standard mounting and gold shadowing techniques. 
Results and Analysis 
Arphia sulphur ea and A. conspersa have five acoustical signals 
which Otte (1970) and Willey & Willey (1969) have discussed in 
detail. Of these, I have filmed the chirps (ordinary stridulation) 
produced during contra- and ipsesexual courtships and the flutter- 
rasps (femur-shaking with wing-striking) during male-to-male in- 
teractions. Only the chirps will be discussed in this paper and are 
known to be produced by rubbing a ridge on the medial surface of 
Fig. 3. Lateral view of Arphia sulphur ea showing position of inter- 
calary vein dorsal to the long median vein. 
Figs. 4-6. Secondary emission electron photomicrographs of the stridu- 
latory apparatus of A. sulphurea male seen in Fig. 3. 
Fig. 4, oblique view of intercalary vein from 20° above the surface of 
the tegmen, arrow points to the basal origin of the vein, 127 X- 
Fig. 5, lateral view about 19° from horizontal plane of the tegmen, 100X. 
Fig. 6, vertical view of medial surface of the right mesothoracic femur, 
arrow points to the area of the femoral ridge which contacts the tegminal 
file, 20X. 
