THE CRANBERRY GIRDLER. 15 



this treatment is very satisfactory from the standpoint of destroying 

 the girdlers, it may result in a very poor bud formation and a light 

 crop of berries the following year. Some of those who have tried 

 holding the flowage until mid-July have reported that the crop 

 the year following yielded an increase of 100 per cent over a normal 

 one, showing that this treatment may be used without monetary loss, 

 provided frosts, which may destroy part of the prospective double 

 crop, are not encountered in the cropping year. 



Holding the flowage until July 14 or later results in the loss of 

 the current year's crop, but this procedure is good practice where the 

 girdler infestation is severe and perhaps complicated by an infesta- 

 tion of the blackhead fireworm {Rhopobota vacciniana Pack.). 

 Considerable expense is saved the grower by allowing the bog to 

 go one year without a crop, and the treatment always results in 

 producing a cleaner bog, especially if the one so handled has been 

 invested by grass and weeds. 



June 18 is the latest date, in the knowledge of the writer, to which 

 the winter flood can be held and a good crop secured the same 

 season. This was accomplished on a deep-flowed bog of Early 

 Black vines near Pemberton, N. J. 



In the event of holding the winter flowage until July 15, or a 

 little later, successful control of the girdler will be secured, but not 

 extermination. A few of the insects will escape even this treatment, 

 and at the end of three or four years the infestation again may be 

 severe. The mistake made by many growers is in permitting the 

 injury to assume large proportions before attempting control. The 

 first signs of girdler injury should be noted and the remedy applied 

 before the pest gains headway and large areas of vines are destroyed. 

 The presence of large numbers of the moths on a bog in June and 

 July should serve as a warning that the vines are in a fair way of 

 being severely damaged. 



FALL FLOODING. 



Fall flooding affords the most satisfactory control of the girdler, and 

 will result in practical extermination of the pest until reinfestation 

 comes from the upland or other bogs, if it is applied at the proper time. 

 As shown in the study of the seasonal history, the larvse make co- 

 coons in the fall, and if the fall flowage is applied after the cocoon 

 is formed, the larva within will not be injured, even though this 

 flowage lasts two weeks or more. However, if the flowage is applied 

 before cocoon making begins, the naked larvae will be killed certainly 

 in a week, and it is probable that five days is ample time for sub- 

 mergence, although some growers prefer to hold the flowage two 

 weeks to insure a thorough treatment. 



For New Jersey, cocoon making begins in a large way the first 

 week in October, and it is therefore essential to reflow the bog dur- 



