45 



winter of 1909-10. A joint estimate of the egg clusters in this locality 

 made with the assistant of the division agent in the spring of 1910 re- 

 sulted in finding about 500 clusters. 



The rearing of caterpillars was undertaken by Mr. Phillips's as- 

 sistant. On June 20, 1910, he noticed the first dead individuals in 

 the brood. Three days after the receipt of this communication I went 

 to Beverly to inspect the material. Many of the caterpillars had 

 already died from the wilt. This same day (June 25), with the help 

 of the assistant, one part of the material was exposed in the western 

 portion of the locality mentioned. The bag containing the material 

 was fastened about 6 feet from the ground, between limbs with dense 

 foliage. Most of the caterpillars of this locality had at this time just 

 passed the third molt. 



After the wilt had operated all through the summer among the cater- 

 pillars of this locality, the place was visited again on Sept. 13, 1910, 

 together with Mr. Phillips's assistant. We estimated the number of 

 fresh clusters present to be about 250. The decrease in the size of 

 the clusters compared with those of the previous year was very strik- 

 ing. The examination of the first 5 clusters which were found gave 

 the following result : 



Cluster 1. 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Total, 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Total, 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Total, 



Unfertilized eggs, . 

 Eggs with dead embryos, 

 Eggs apparently alive, . 



Total, 



= 13.60 per cent., or about 13.5 per cent. 

 . 108 =86.40 per cent., or about 86.5 per cent. 



. 125 eggs. 



Cluster 2. 



2\ 



g } = 5.92 per cent., or about 6 per cent. 



. 159 =94.08 per cent., or about 94 per cent. 

 . 169 eggs. 



Cluster 8. 

 Q I = 7.37 per cent., of about 7 per cent. 



J 



88 =92.63 per cent., or about 93 per cent. 

 . 95 eggs. 



Cluster 4. 



y \ = 5.76 per cent., or about 5.5 per cent. 

 . 131 =94.24 per cent., or about 94.5 per cent. 



139 eggs. 



