1914.] PUBLIC DOCUMENT — No. 31. 31a 



materials being deferred until July 15, with a view to avoiding 

 the possible loss through reflowage, which it was believed might 

 be necessary up to that date for protection from insects or frosts. 

 There was no increase in crop as a result of the application of 

 any of the fertilizers ; indeed, the fertilized plots gave somewhat 

 smaller yields than the unfertilized. Whether this was due to 

 the lateness of the application is uncertain. The result is, 

 however, the opposite to that which was obtained in 1912. 



A large part of the work of Dr. Franklin has consisted in 

 further study of the various insects which affect the crop. The 

 observations made and the results obtained are fully set forth 

 in Dr. Franklin's report. Among the more important conclu- 

 sions which appear to be justified are the following: — 



Careful observations have been made on a span worm 

 (Epelis truncataria var. faxonii Minot). The pupa? are not 

 destroyed by winter flowage. Heavy sanding kills most of them. 

 In cases of very heavy infestation burning over the bog may 

 be the best course to take in order to get rid of the insect. 



Observations and further experiments on the flowed bog fire- 

 worm (Rhopohota vacciniana (Pack.)) indicate that late hold- 

 ing of the winter flowage (until about June 1), and reflowing 

 about three weeks later, is an effective means of destroying this 

 insect. Spraying with arsenates is also useful, but whether 

 arsenate of lead or Paris green should be preferred is not yet 

 certain, although it is believed that the arsenate of lead is the 

 better of the two. There appears to be a considerable differ- 

 ence in the extent to which different varieties are attacked by 

 this insect, the Late Howe being much more seriously injured 

 than the Early Black. 



A number of important parasites of the fruit worm (Mineola 

 vaccinii (Riley)) have been discovered and studied. The most 

 important among them ap])ears to be Plianerotoma tibialis. 

 Just how important this will prove to be in helping to control 

 the fruit worm is not yet clear. Observations indicate that 

 parasites are much more abundant on dry bogs than on those 

 which are flowed. 



Flowage experiments indicate that fall flowage, whatever 

 the depth, is not effective in destroying the fruit worm. Experi- 



