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



The results given below have been compared with the results with 

 the same food plants growing in the open in so far as this data is 

 available. 



Spreckled Alder and Willow. 



Larvae fed on both species, but appeared to prefer alder in all stages. After 

 the foliage on alder was nearly all eaten tbe larvse attacked the willow. 



More adults were reared from these trays than from either alder or willow 

 when fed alone. The larvae grew steadily and attained large size. 



In the field both alder and willow, when growing together, are defoliated if 

 the infestation is heavy. The alder is usually stripped first. 



American Beech and Chestnut. 



Larva? fed freely on the beech in the first two and last two stages. In the 

 first stage there was no feeding on chestnut, and during the second stage the 

 feeding was light, increasing to free in the third and fourth. After the fourth 

 stage feeding decreased on chestnut. Preference for beech was noted except 

 in third and fourth stages. 



Larvse grew to medium size and a fair percentage reacbed the adult stage. 



American Beech and Bed Oak. 



Both of these foods were eaten freely throughout the experiment. Oak was 

 a decided favorite in the first five stages. In the sixth stage feeding decreased, 

 as the larvse preferred the more tender leaves of the beech. The larvse grew 

 rapidly and were of large size. A good percentage reached the adult stage. 



In the field the larvse fed on the beech in the first two stages, then changed to 

 the oak, where they fed until the last stage, when they returned to the beecb. 



American Beech and Sugar Maple. 



Both these food plants were fed upon freely until the fifth stage, then mod- 

 erately. A slight but continued decrease was noted on maple from the begin- 

 ning of the fifth stage to the closing of the trays. Very little preference was 

 observed in the first four stages. 



A few larvse reached the adult stage. 



Black Birch and Witch Hazel. 



There was no feeding on the birch during the first stage and but very little 

 in the second and third. In tbe fourth and fifth stages the larvse preferred the 

 birch. The larvse fed freely on witch hazel in the early stages. The cater- 

 pillars were small and reproduction resulted from this experiment. 



Gray Birch and Chestnut. 



There was no feeding on the chestnut during the first stage, but a steady 

 increase was noted thereafter. Feeding was constant on the gray birch in all 

 stages. 



The larvse grew slowly and were of small size and but few reached the adult 

 stage. 



