Biology of the Membra cidae of the Cayuga Lake Basin 189 



P'or the period represented in the table, the following temperature 

 data, valuable for consideration in ecological studies, may be noted: 



Mean annual 47° 



January average 24° 



July average 71° 



Highest, 102°, Julv 4, 1911 



Lowest, —20°, December 20, 1884, and January 19, 1904 



Most days with temperature of 90° or above in one month, ten, in July, 1911 



Most days with temperature of or below in one month, twelve, in February, 1885 



Warmest month, July, 1887, average 74.8° 



Coldest month, February, 1885, average 15.3° 



Second only in importance to the question of temperature in the study 

 of biologic conditions in insects, is that of precipitation. This average 

 for Ithaca is as follows: 



Average Precipitation at Ithaca (Inches) 



January 2 . 16 



February 1.87 



March 2.44 



April 2.29 



Mav 3.4:3 



June 3.88 



July 3 . 75 



August 3 . 24 



September 2.83 



October 3.17 



November 2 . 58 



December 2 . 64 



Annual 34.28 



Of particular interest in this study has been the rainfall during the 

 summer months of the last five years. This is as follows: 



Rainfall at Ithaca in Summer (Inches) 



April 



May 



June 



July 



August . . . 

 September 

 October . . 



1916 



A. 21 

 3.48 

 1 29 

 1.50 

 5 65 

 1 59 



The bearing of these data on the ecological studies of the Membracidae 

 will be discussed later, but it may be noted here that during this period 



