THE CRANBERRY GIRDLER. 7 



SEASONAL HISTORY. 



The seasonal-history data were secured on numerous bogs through- 

 out the State of New Jersey and in rearing cages kept in a screened 

 open-air insectary. Four-ounce ointment oans were satisfactory for 

 securing the feeding, cocooning, and pupation data, while for ovi- 

 position data and caging the moths a cloth-covered lamp chimney 

 was found to fit tightly over a 1-ounce ointment can. 



ADULT STAGE. 



The time of emergence in the spring and summer depends largely 

 upon whether the bog is a dry one or a flowed one and on the date 

 of drawing the winter flowage. 



Dry-hog conditions. — Cocoons kept at the laboratory during the 

 winter of 1914-15, under approximately dry-bog temperatures, 

 yielded moths from May 11 to June 18. In the cranberry bog where 

 winter flowage was removed on April 10, moths began flying June 7. 



Winter -flowage drawn May 10. — This represents probably the 

 average date at which New Jersey growers remove the winter flowage. 

 From a large mosquito-bar cage placed over an infested area of 

 cranberry vines bared of winter flowage on the 10th of May, adult 

 emergence was noted from June 10 to July 8. The complete record 

 appears in Table I. 



Table I. — Emergence of cranberry-girdler moths on cranberry bog, Whitesbog* 



N. ./., 1915. 



Date of removal from cage. 



Number 

 of moths. 



Date of removal from cage. 



Number 

 of moths. 





16 

 48 

 42 

 117 

 24 



June 18 



3S 







10 





July 2 



\ 





July 8 



I 













Keeping the winter flowage on a bog until some time after May 10, 

 in the region of New Jerse}^, produces a later emergence of moths. 

 There is a date, however, which no one as yet has determined definitely, 

 when, owing to the lateness of holding the flowage, the immature 

 stage of the moth is killed. One observation was made in 1916 on a 

 bog at Howardville, N. J., showing that, although the winter flowage 

 had been held until July 12, a number of the girdlers in the immature 

 stages were able to survive this treatment, and moths were found 

 flying August 3. • 



On grassy bogs and on bogs bearing a heavy mat of vines the 

 emergence of the moths may be prolonged over a long period. At 



