REPORT OF CRANBERRY SUBSTATION FOR 1914. 103 



Table 5. — Effect of Fertilizer on Setting of Fruit. 



As the table indicates, there was a distinct increase in fruit on the 

 "Early Black" plot as compared with the surrounding bog, though it 

 was much less marked than that on the "Late Howe" plot, probably 

 because of the difference in the development of the bloom when the 

 fertilizer was apphed. It will be seen at once that the increase in quan- 

 tity was in neither case due, to any considerable extent, to an increase 

 in the size of the berries, and that the fertihzer had apparently caused a 

 greater number of blossoms to set and form fruit with both varieties. 

 In storage tests there was slightly more decay among the berries from 

 the "Late Howe" plot than among those from its check. The "Early 

 Black" fruit was not tested in this regard. 



Insects. 



The insect studies have covered a rather wide range during the year. 

 The flowed-bog fireworm (black head cranberry worm) and the fruit 

 worm both seem to have been much less abundant than usual, the total 

 injury caused by them probably being about the same as in 1913. 



In May and June the forest tent caterpillar (Malacosoma disstria Hiib- 

 ner) was very abundant everywhere in the cranberry section, and the 

 worms crawled onto the bogs in large numbers. Their operations were 

 watched carefully, but they were never found feeding on the cranberry 

 vines, and their presence on the bogs need never cause concern, for their 

 normal food plants are evidently so different from the cranberry that 

 the latter is not palatable to them. 



Cape Cod, in common with many other sections of the country, suf- 

 fered this year from a rather severe visitation of the army worm (Helio- 

 phila unipuncta Haworth). It did quite a little damage on bogs here and 

 there, but the cases of great injury appear to have been few. The cran- 

 berry is evidently not a favorite food plant with this insect. It usually 

 works on grasses, grains and corn. As it prefers low lying land, however, 

 the moths frequently, in "army worm years." deposit their eggs m quan- 

 tities on the bogs, and then the vines are attacked because of the absence 



