?40 MAINE AGRICULTURAL EXPERIMENT STATION. I907. 



Any work, therefore, either systematic or ecological, under- 

 taken with this genus should be pursued with the idea that it 

 shall in some way lessen instead of augment the confusion 

 which already exists with this group of plant lice. The obser- 

 vations recorded for A r . solanifolii in the present bulletin are 

 meagre but they all unquestionably refer to the single species 

 under consideration. It seems advisable to tabulate such facts 

 as have been ascertained now rather than to wait for the accu- 

 mulated observations of a longer period for 2 reasons. The 

 economic point involved — that is, whether N. solanifolii might 

 practically be combated upon its winter host — seems to be 

 answered by the evidence now at hand. Then, too, over those 

 parts of the State which were under observation this season, 

 N. solanifolii upon the potato was apparently so nearly exter- 

 minated by fungus parasitism that it is probable that some time 

 will elapse before this species again appears in the State to an 

 extent great enough to make further work with it practical. 



Nectarophora Solanifolii from Field Observations. 



The points which were evident for this species in Maine from 

 field observations upon the potato for the 3 seasons 1904-1906 

 were that about the middle of July a very few scattered indi- 

 viduals may be seen upon the potato; that before the last of 

 August the infestation may become excessive, the tips of the 

 stalks, flower stems and terminal leaves being packed with 

 plant lice; that by the middle of September the fall migration 

 is over ; and that the migration takes place before the'true sexes 

 appear, neither the oviparous female nor the male occurring 

 upon the potato in the field. The points in the life history 

 which were not known and concerning which it was desirable 

 to obtain data were upon what plant the spring generations 

 lived ; whether this Nectarophora would accept more than one 

 host beside the potato (that is, whether it was. a "general" or 

 a "specific" feeder) ; whether the true sexes appeared in the 

 fall, and if so where the eggs were deposited. 



A few dates may be quoted here for instance. 



August 11, 1904, Houlton. — A correspondent who had been much wor- 

 ried by a bad infestation sent in a box of N. solanifolii mostly winged 

 or within one molt of being winged with the comment : "I do not find 



