42 



Cluster 5. 



Unfertilized eggs, ^ I j - 6.06 per cent., or about 6 per cent. 



Eggs with dead embryos, . 2 J 



Eggs apparently alive, . . 31 =93.94 per cent., or about 94 per cent. 



Total, .... 33 eggs. 

 The average of these 5 clusters gives the following result : 



Dead eggs, . . . . 60 = 15.23 per cent., or about 15 per cent. 

 Eggs apparently alive, . . 334 = 84.77 per cent., or about 85 per cent. 



Total, .... 394 eggs. 



Since this place, in which Flacherie had operated, contained on the 

 average only 334 eggs Avith apparently living embryos per cluster, the 

 size of these clusters was about one-quarter less than normal. The fresh 

 clusters, which were estimated to be about 60, i.e., the same number 

 which was found in the spring, thus must be reduced to about 45. The 

 number of apparently living eggs of this locality therefore was de- 

 creased, after the wilt had worked, to about 77 per cent. 



This experiment also shows that the exposure of sick instead of dead 

 caterpillars contributes to the spread of the wilt. As in such cases, 

 however, the disease spreads slowly, the caterpillars, it is true, will not 

 be killed in large numbers, but they will be infected more or less 

 lightly. The result is that a high percentage of the eggs deposited 

 by the females will fail to hatch. 



The second place which was selected in Kingston for an experiment 

 is situated on the eastern side of Jones River, opposite the poor farm. 

 This is an isolated wood of about one-eighth of an acre in size, which 

 contains several large oaks and underbrush. The gypsy moth was dis- 

 covered here also by the finding of egg clusters first in the autumn of 

 1909. It cannot be stated whether disease was present among the cater- 

 pillars of the summer of 1909, but this seems improbable, owing to the 

 youth of the colony. Several of the clusters were killed with creosote, 

 but there were still left, according to Mr. Souther's estimate, about 

 50 clusters. 



The planting of the sick material was accomplished on the same 

 day and in the same manner as in the first locality. Estimating the 

 fresh clusters on Oct. 25, 1910, unfortunately I found that most of 

 these fresh clusters (about 25) had been already killed with creosote 

 by the men working under the local superintendent. Even with the 

 assistance of the local superintendent, only 2 untouched egg clusters 

 could be found. Only 1 of these could be collected, since the second 

 was out of reach. Although, therefore, we are unable to draw any 



