Biology of the Membracidae of the Cayuga Lake Basin 391 



The literature referring to hosts adopted by Membracidae is not 

 extensive and is widely scattered. The most important contribution 

 to the subject was made by Goding (1893 a) in a published list of food 

 plants of the family; Miss Branch (1913:113-114) has published a hst 

 of the host plants on which the Kansas forms have been taken; Van Duzee 

 (1908 a) mentions the hosts on which a number of species are commonly 

 taken; and various economic papers (Hodgkiss, 1910; Wildermuth, 1915) 

 and life history reports (Matausch, 1910, a and c, and 1912 a; Funkhouser, 

 1915, b, c, and f) have discussed the hosts of the particular species in 

 question. These publications have, however, been ignored in this study 

 except in so far as the data mentioned have been verified by actual obser- 

 vation as holding true for the Cayuga Lake Basin. 



MIGRATIONS 



The migration of the Membracidae is apparently very slow both as 

 regards change of locality and change of host plants. So far as local 

 records show there is no reason to believe that any species has changed 

 its habitat to any great extent during the years in which this study has 

 been in progress. The same forms may be found in the same locality 

 year after year while neighboring localities offering the same natural 

 conditions remain unentered. Records for other parts of the State and 

 for the country in general would seem to indicate that this slowness of 

 migration is characteristic of the family. 



The same is true in regard to migrations from one plant to another. 

 It often happens that one tree may be literally covered with individuals 

 of a species, while another tree of the same kind, in close proximity to the 

 first, may be unmolested; and these conditions may be noted season after 

 season. 



The reasons for such reluctance in seeking new localities and new hosts 

 are not evident. The insects fly well for short distances and should be 

 able without difficulty to spread over a considerable area in a season 

 provided the desired host is abundant thruout the area. This, however, 

 appears not to be the case and probably explains why the Membracidae 

 are not often noted as economic pests. 



The migration of the nymph from the hosts on which the eggs are laid 

 to the feeding plant, in cases in which such movement is part of the life 

 history, is regular and definite. The distance covered, however, from the 



