80 Annals Entomological Society of America [Vol. X, 



work. The list as determined numbers 206 species and 

 varieties, representing 38 genera, and is second in number of 

 species to the Tennessee list containing 212 species, which was 

 published last year by the junior author. 



In Maine, a state with a similar location and having a 

 flora similar to that of Wisconsin, it is interesting to note 

 that of 151 species collected by Professor Herbert Osborn, 

 only 33 species of that list were not taken in Wisconsin, while 

 108 were found there. In the Tennessee list we find 99 species 

 occurring which have not been taken in Wisconsin, while 113 

 species are common to both states. 



The Wisconsin list has extended the known range of a 

 number of species which were supposed to be restricted to more 

 southern areas. The southern fauna seems to extend up the 

 Mississippi River Valley as far north as St. Paul, and apparently 

 works northward through the deep valleys adjoining this 

 valley. As an instance, Deltocephalus vinnidiis Crumb, described 

 from Tennessee a year ago, was found in central Wisconsin, 

 while Acinopterus acuminatus, a typical southern form, was 

 found well up in Wisconsin, although it is rarely found north 

 of the Ohio River. 



The northern portion of Wisconsin, which produces many 

 Canadian forms of vegetation, and is dotted with many lakes 

 and swamps, contains a rather limited number of peculiar 

 species found only under such conditions. 



The best collecting for the species of this group is in localities 

 where the vegetation is in its most primitive condition — not 

 having been disturbed by farm practices or any form of cul- 

 tivation, and in the absence of forest or prairie fires. From 

 these facts we can readily observe that usual farm practices 

 of cultivation and rotation of crops, as well as the burning-over 

 of infested land, are factors in checking the multiplication of 

 these species and their resulting damage to crops. 



Leaf hoppers are more or less restricted to certain food 

 plants, although some species seem to have but slight preference. 

 In order to carry on satisfactory economic controls it is neces- 

 sary to know where and under what conditions these forms 

 occur naturally, and to determine their habits, including egg 

 deposition, the methods of feeding and the form in which the 

 species hibernates. 



