146 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



of a light, whether these be species of Orchelimum, Conoce- 

 phalus, Amblycorypha, or (Ecanthus. In truth, iu many 

 instances, the stridulations of some insects are more persistent 

 when the light is kept very near them. 



In a study of the stridulations of Orthoptera throughout 

 the season, it becomes evident that these creatures possess re- 

 markably responsive sensibilities to variable weather condi- 

 tions. Slight changes in light, temperature, moisture, and 

 air- movements have their peculiar influence upon the charac- 

 ter of their stridulations. It seems hardly probable that those 

 species which stridulate during darkness have developed this 

 habit to escape daylight enemies. If it were merely a ques- 

 tion of darkness why do most nocturnal katydids and crickets 

 show no fear of a strong light? In our illuminated city parks 

 these insects are just as noisy in the glare of electric lights as 

 away from them. This is especially true of Micro centrum 

 lanrifoliuni Linnaeus. Temperature and moisture changes 

 attending darkness rather than darkness itself probably ac- 

 count for the musical activities of certain crickets and katy- 

 dids at night. I have several times noted that those species 

 which stridulate entirely during darkness in midsummer may, 

 in the autumn, when the nights have become too cold, stridu- 

 late entirely by daylight. Observations of the stridulating 

 habits of Cyrtophyllus perspicillatus in north Georgia at 

 different times during the season have brought out very in- 

 teresting facts of this kind. Throughout the warm summer 

 nights in this region these noisy katydids keep up their inces- 

 sant stridulations. I have rarely heard one stridulate during 

 sunlight. However, late in September, during a brief period 

 spent in the mountains of Towns County, north Georgia, I 

 met these katydids stridulating under very unusual conditions. 

 Following one of the earliest and most severe cold waves ex- 

 perienced in this region in many years the nights became so 

 cold that all insect life was forced into silence. However, 

 during the bright, sunnv afternoons, at 2 o'clock, I heard the 

 rasping notes of Cyrtophyllus perspicillatus in the tall trees, 

 and captured one individual for identification, as I had sus- 

 pected something different at this unusual hour. In this in- 

 stance, notwithstanding the bright sunlight, the stridulatory 

 activities of these katydid^ were a response to the more favor- 

 able temperatures of mid-afternoon. Throughout the summer 

 I have many times noticed that the peculiar atmospheric con- 

 ditions immediately preceding thunderstorms at night cause 

 many stridulating Orthoptera to become very musical until 

 the storm had passed. 



