1983] 
Henry — Chrysoperla plorabunda 
345 
temperatures, since mutual recognition of highly specific call fea- 
tures is so important to the reproductive success of both members of 
each courting pair. Here, 1 report on the effects of temperature 
change on the principal parameters of the calls of individual male 
and female Chrysoperla phrahunda from North America. This 
paper also contains the first complete description of the frequency 
structure of the abdominal volleys of that species, together with an 
experimental analysis of the effects of abdominal mass on frequency 
characteristics. Regressions of call parameters against temperature 
in Ch. plorabunda are compared with those described for other 
singing insects, in an attempt to identify any unifying principles. 
Materials and Methods 
A breeding colony of Chrysoperla plorabunda was started in the 
fall of 1982 from seven males and ten females collected in a field of 
senescent goldenrod (Solidago spp.) at Storrs, Connecticut. Subse- 
quently, adults were maintained on a WheasT“/ sucrose diet while 
larvae were fed ether-killed Drosophila spp. (see Henry 1979, 1983a 
for details). Males for experimentation were drawn from second- 
generation laboratory stock, while females were third-generation 
insects; five unmated individuals of each sex were acoustically moni- 
tored at various temperatures between 19.5°C and 29.8° C. For each 
of five call characteristics of interest, 1 analyzed an average of 40 
volleys of abdominal vibration per individual, delivered at three to 
six different temperatures between the extremes mentioned above; 
in no case was a regression line for an individual based upon fewer 
than 18 volleys. Temperature was monitored within 25 cm of the 
calling insects, and was controlled by heating and cooling an entire 
120 cubic meter room. 
Lacewings were induced to call either by playing back to them 
cassette tape recordings of conspecific signals or by simulating such 
signals by means of a sweeping audio frequency generator (Tek- 
tronix^** FG 507) gated by a physiological stimulator (Harvard 
340). Patterns of abdominal vibration were detected and analyzed 
with techniques and equipment described in other papers (Henry 
1980a, 1982b). Details of call parameters were obtained from Pola- 
roid photographs of oscilloscope tracings, using conventional 
overlay methods. 
Several individuals of Ch. plorabunda from a breeding colony of 
different geographical origin were selected for use in experiments 
