INJURIOUS INSECTS OF I9Q09 AND IQIO. 31 
Empoasca mali. 
Alfalfa and dahlia plants, which had been badly infested with 
Empoasca mali during the summer and fall of t908, were brought 
in and placed in the insectary, and kept in the cold part of the 
greenhouse through the winter. These plants showed the effect 
of the insect’s attack plainly when brought in, and there were many 
of the insects still on them at that time—October 8th. No speci- 
mens of Empoasca mali lived through the winter on these plants, 
and no nymphs emerged from the tissues the next spring (spring 
1909). This goes to show that E. mali does not deposit winter eggs 
in the tissues of herbaceous plants, and that the species relies entirely 
upon the eggs deposited in the blisters found on the bark of peren- 
nials. These plants were last examined in the season of 1909 on 
June 5th, and the plants were at this time more or less dead and 
dry, except for the new growth which had started up during the 
month of May, 1900. 
Fig. 15. Emergence of nyniphs from egg blister. Original. 
Apple branches were examined in the orchard early in the 
spring and were brought in from time to time, and the egg blisters 
of E. mali carefully examined, to find out when the nymphs should 
begin emerging from the blisters. Nymphs were found in process 
of emerging on May 24th, the apple leaves at this date being not 
over one-third developed. Numerous hoppers were found at this 
date in first and second instars on the apple leaves, and it seemed 
probable that some of them hatched from the eggs as early as 
May 2ist. Several adults were reared from nymphs hatched from 
these blisters, and, with one exception, they all proved to be E. mali. 
One undetermined specimen, which was slightly smaller than 
E. mali, was reared from a nymph which emerged from an egg- 
