30 BULLETIN 250, U. S. DEPARTMENT OF AGRICULTURE. 



Yellow Birch and Hemlock. 



Larvae fed on the birch freely in the first four stages and more moderately 

 in the latter stages. No feeding occurred on hemlock in the first and second 

 stages. It was slight in the third and continued light in the remaining stages. 



Larvae grew rather slowly and were of small size and a few changed to 

 adults. 



Yellow Bibch and Red Maple. 



Larvae fed more freely on birch than on maple, and the same proportionate 

 feeding was maintained throughout the experiment. They were of small size 

 and were badly attacked by disease. A small number reached the adult stage. 



Yellow Bibch and Sugar Maple. 



The larvae fed moderately on both food plants, with a slight preference for 

 the birch at times. They grew slowly and were of moderate size. A few males 

 and females were obtained. 



Yellow Birch and Witch-hazel. 



There was moderate feeding on both these food plants, but at times some 

 preference was shown for witch-hazel. Growth was rather slow and the larvae 

 attained moderate size. A few males resulted. 



Low Blttberry and White Pine. 



This is the most unfavorable of the blueberries. Feeding was very light in 

 the early stages and increased later, but at no time was this plant eaten freely. 

 There was no feeding on pine in the first three stages. It was light in the 

 fourth and increased in the later stages. Larvae grew slowly in the early 

 stages, but much more rapidly later, and reached medium size. Only males 

 were obtained. 



In a single location in the field the blueberry was very slightly eaten by 

 first-stage larvae, but no feeding was noted by the later stages. The infestation 

 was light and no defoliation resulted to either the blueberry or pine. 



Tall Blueberry and White Pine. 



The feeding on blueberry by the first and second stage was light and there 

 was great variation in the rapidity of growth. In the remaining stages feeding 

 was free. Pine was not eaten in the first two stages. In the other stages it 

 was fed upon slightly, but not freely. The larvae grew quite rapidly and reached 

 medium size. Adults of both sexes were obtained. 



Bluebebby and White Pine. 



This blueberry is the most favored of the blueberries, and larvae fed freely 

 upon it in all stages. Pine was not eaten at all in the first two stages, but 

 feeding increased in the later stages, when it was of ion oaten from choice. 

 The larvae grew rapidly and attained average size, and males and females 

 developed. 



Field reports show nearly complete stripping of the blueberry, but almost 

 no injury being done to the pines. 



