REPORT OF CRANBERRY SUBSTATION FOR 1914. 107 



5. This seems to have been a year of exceptional tip worm abundance. 

 It is not yet certain why resanding, winter flooding, difference in variety 

 and frost have bearings on the prevalence of this insect. It seems evi- 

 dent, however, that resanding every other year should be recommended 

 as a wise preventive practice against it. 



The injury caused by this brood which does its work during the time of 

 full bloom is a matter of great importance. It has undoubtedly been 

 the cause of many a crop failure supposed to have been due to other 

 troubles. Early in October, the tips on the station bog were carefully 

 examined to find out whether there had been much recovery from this 

 injury. It was found that less than half of the injured tips had formed 

 buds for next season. The following count of "Late Howe" tips, made 

 on October 1, showed the most recovery of all the counts made: tips not 

 injured, 39; injured tips which had recovered and formed buds. 31; 

 injured tips which had not formed buds, 34. In many cases the buds on 

 the recovered tips were undersized, and it seemed doubtful if the majority 

 of them were normal. The poor recovery on the station bog may, of 

 course, have been due to a devitalized condition of the vines, but the 

 evidence at hand indicates that this insect is a very serious pest. 



The Flowed-bog Fireivorm {Rhopobota vacciniana (Pack.)). 

 General observations concerning this insect were made during the 

 year, but no extensive experiments were carried out with it because the 

 tip worm and fruit worm monopolized attention. It seems wise, however, 

 to sirni up in this report the possibiUties for treating this insect satis- 

 factorily. 



1. Where reflowing can be done in June, reasonably effective treat- 

 ment may be had by using the water according to suggestions and rec- 

 ommendations made in previous reports, and perhaps no improvement in 

 treatment is possible for such bogs. 



2. Winter-flowed bogs which cannot be reflowed must either have the 

 flowage held late enough (until, perhaps, June 20) to kill the eggs, as 

 often as an infestation develops sufficiently to do serious damage, the 

 crop being sacrificed in the years of such late holding, or else be sprayed, 

 if any direct treatment is to be apphed at all. Arsenical poisons seem 

 to have been pretty thoroughly tested by the growers in practical spray- 

 ing for this insect. A great advantage is often obtained by their use, but 

 under some conditions the results are very unsatisfactory, and the fre- 

 quent failures with such treatments have created a general desire for 

 some better method. Only one possibility for great improvement in 

 spraying treatments seems to present itself. Possibly a sweetened spray 

 would be attractive to the worms. Some growers claim to have tried 

 such a spray with exceptionally good results, but it is doubtful if this 

 method of treatment will be found practicable on more extensive trial. 

 Sweetened sprays are nowhere widely used in treating any chewing insect, 

 and if such a treatment were practicable it would probably have come 



