Biology of the ]Membracidae of the Cayuga Lake Basin 191 



It will be noted that the summer of 1914, besides showing extremes of 

 sudden rainfalls, had a heavy average precipitation. The effect of this on 

 the life histories of certain Membracidae has been noted (Funkhouser, 

 1915 f: 191), and a comparison of the summers of 1913 and 1914 in the 

 effect on the insects in general is shown in a later table in this paper 

 (page 411). 



The snowfall in the basin is not excessive but shows considerable varia- 

 tion. This, however, affects the biology of the insects under considera- 

 tion only in a slight degree, and only those forms that hibernate in the 

 earth during the winter. The climatological data on this point arc given 

 in the local weather bureau report already cited (footnote 4) as follows: 



Average Monthly Snowfall at Ithaca (Inches) 



January 13 



February 12 



March.' 10 



April 4 



May between . 1 and .5 



October .between 0.1 and 0.5 



November 5 



December 11 



Annual 56 



Most snowfall in one winter, 79 inches, 1910-11 

 Least in one winter, 28 inches, 1912-13 

 Most in a month, 45 inches, December, 1902 

 Least in a winter month, 2 inches, Januarj', 1913 

 Latest in spring. May 28, 1902 

 Earhest in fall, September 30, 1889 



More important than the snowfall is the question of the date of killing 

 frosts in spring and in autumn. A comparison of these dates with those 

 of the appearance and the disappearance of certain Membracidae has 

 proved extremely interesting. Fortunately the records of frosts have been 

 carefully kept at the local weather bureau, and a valuable report has been 

 made on the subject.^ This report gives the following data for the city of 

 Ithaca, which, while not applicable to the entire basin, is general enough 

 to be of practical value: 



Average date of last killing frost in spring, May 4 

 Average date of first killing frost in fall, October 10 

 Number of davs between these dates, 159 



5 Wilson, Wilford M. Frosts in New York. Cornell Univ. Agr. Exp. Sta. Bui. 316 : 505-568. 1912. 



