OBSERVATIONS DURING THE SEASON OF 1909. 45 
was found to note the migration of leafhoppers into wheat from 
adjacent grass, as a plat in the experimental grounds where the 
wheat had only recently come up and which was practically free 
from any other kind of vegetation was found to be infested with 
Deltoceplialus inimicus and D. nigrifrons. Collections at Indianapolis 
gave no particulars different from those which have been observed in 
other localities. 
October 20, at Hamburg, N. Y., the author found leafhoppers quite 
active, and in a series of narrow strips of wheat alternating with grass 
it was distinctly noticeable that the leafhoppers had migrated into 
wheat strips in considerable numbers. In another larger field not far 
distant the central part of the field appeared to be less infested and 
it would seem that the distance from adjacent grasses had been a 
factor in the lesser infestation. This field, however, was too small to 
give a very good opportunity for noting the distances to which the 
leafhoppers can easily migrate. 
At Valencia, near Pittsburgh, Pa., November 2, the author found 
Deltoceplialus inimicus and D. nigrifrons with Phlepsius irroratus, 
Cicadula 6-notata, and a species of Balclutha, all in small numbers, 
probably because of the rain and cold which must have driven them 
to shelter. Some were found under dead leaves, but others had been 
exposed, as their movements were sluggish. Most of the leafhoppers 
seemed to be very well prepared for hibernation, at least were too 
inactive to furnish much opportunity for examination. 
In the vicinity of Harrisburg, Pa., November 4 and 5, several 
fields were visited, and practically no jassids whatever were found 
in the fall wheat, a condition which seemed quite puzzling, since 
the weather was warm enough so that the jassids should have 
been active. The author learned, however, that the protracted 
drought had dried up the vegetation in early autumn and inasmuch 
as the fields examined were mostly upland and as the small amount 
of grass adjacent had probably been too small to support the jassids 
earlier in the season there had been no infestation of the wheat. In 
one field of grass, distant from the wheat fields examined, a small 
number of Deltoceplialus inimicus, D. nigrifrons, and AgaUia 
sanguinolenta as well as a Liburnia were found. The observations 
here appeared to be distinctly significant as showing the possibility 
of preventing injury to faU wheat by the elimination of jassids 
developing in the adjacent grass fields. 
At Reading, Pa., November 6, on a bright, warm day, in fields east 
of the town, several species of j assids were found, among them Delto- 
ceplialus sayi, D. nigrifrons, and Dr. mollipes. Wheat fields nearby, 
however, were very clean, free from weeds or grasses, except timothy, 
which was just appearing above the ground. The jassids were quite 
few in the wheat, and in the central part of the field, excepting 
representatives from the adjacent grassland, very few were to be 
found and none at all at the center of a large field. In none of the 
