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[Vol. 85 
testing the effect of abdominal weight on vibrational frequency. 
This stock was bred from five males and five females collected in the 
sagebrush country of southwestern Idaho on 24 May, 1983 by Dr. 
James Johnson (University of Idaho). I tested one field-caught 
male, two first-generation laboratory males, and one first-gener- 
ation laboratory female for the frequency characteristics of their 
calls at two different temperatures; after ascertaining that all were 
essentially identical to one another and to Connecticut plorahunda 
in those characteristics, I weighed each individual to the nearest 
tenth of a milligram on a Mettler^“ H6T or Sartorius^“ 1212 MP 
balance and added weight to the middle of their abdomens, using 
water-based Liquid Paper^“. Mass-loaded specimens were then re- 
weighed and tested again for the vibrational frequencies of their 
calls at temperatures in the 25-30° C range. All such frequency 
values were also adjusted to 27° C using linear regression C in Fig. 3. 
Curve-fitting of paired variables to linear, exponential, or 
logarithmic functions employed a program designed for a Hewlett- 
Packard^** HP-25 pocket calculator. Any reference in the Results or 
Figure I. Detailed fragment of the call of Ch. plorahunda, re-drawn from an 
oscilloscope tracing, showing principal parameters A-E defined in text. A = initial 
volley frequency, B = median volley frequency, C = terminal volley frequency, D = 
volley repetition rate, E = volley duration. 
