CAPE COD CRANBERRY INSECTS 41 



easily and soiiietiines rise in clouds from a badly infested area. The period 

 of activity of the moths coincides with that of the brown spanworm cater- 

 pillars, and when both species abound on the same area they often are con- 

 fused in the minds of ornwers. 



Treattiienf. 



Reflooding for 15 hours and spraying with 6 pounds of dry lead arsenate in 

 100 gallons of water are both very effective. Three treatments, about May 30, 

 June 12 and June '2.5, may be necessary because of the long liatching period. 

 The first, especially if flooding is done, often will check other pests also, espe- 

 cially the gypsy moth, the black-headed fireworm, the false armyworm and tiie 

 blossom worm. If the infestation is only mildly serious, two treatments, about 

 June 5 and June 2-5, will suffice. 



Regular resanding tends to keep this pest out, for the sand co\ers many of 

 the eggs so that the worms fail to emerge. 



Brown Cranberry Spanworm."" 



This insect attacks some bog severely almost every year. It broke out on 

 so many in 1919 and 1920 that it was one of the most important cranberry 

 pests. It does more harm than all the other bog spanworms together. 



rUxfrihiitinn and Food Plants. 



This in,sect has been found in Maine, Massachusetts, New York, Colorado, 

 Aliierta and Alaska. Its only known food plants are cranberry and bear- 

 berry''. 



Character of Injury. 



Moderate infestations work much like the green spanworm, nipping oft' the 

 blossoms and small berries, but they attack the leaves more and chew into and 

 eat holes through the flower buds and often excavate the partly grown berries 

 nuich as katydids do. A severe infestation sometimes turns ;i whole bog 

 brown and then many of tlie uiirnis probably die of stnrvation. 



This worm works so late in the season that when its attack is severe it de- 

 stroys all chances of a crop in the following year, and sometimes patches of 

 vines fail to recover fully for a year or two. 



Description and Seas<)n(d Hisforif. 

 The Pupa. 



Tlie pupae winter among the litter under the vines, enduring the winter 

 flood even when it is held till June. They are brown and somewhat over 

 tliree-eighths of ;m inch long and iiave no cocoon. 



The Moth. 



If the winter flood is let oft" before May 1 and the season is warm a few 

 moths often appear late in May, but they usually emerge mostly during the 



46. Ematurgia am ilar i a (Gn.). Heretofore known in cranberry \'\tf;\2it\.ne 3.S Ebelis truncalcria 

 var. faxonii. 



47. Arclosiaphylos Uva-ursi (L.) Spren;^. 



