THE BLACKHEAD FIREWOEM OF CRANBERRY. 



13 



later in the season, when the vines are maturing, these larvae feed 

 principally on the berries, and therefore do more immediate damage 

 to the crop if any remains on the vines. 



The result of the work on all three generations is not only the de- 

 struction of the current season's crop or its material reduction but 

 also the loss of a considerable proportion of the crop the following 

 year, the setting of fruit buds being largely prevented by the attack 

 of the larvae on the terminals. It will thus be seen that the fireworm 

 in one season can very materially reduce the cranberry crop of two 



seasons. 



Fig. 5. 



-The blackhead fireworm : Injury of the larvffi to the berries, 

 the upright is uninjured. 



The large berry on 



Place of Pupation. 



After the larvae have reached their full growth they usually leave 

 the webbed uprights and descend to the trash and leaves beneath the 

 vines, where they inclose themselves between several old leaves in more 

 or less loosely constructed cocoons, typical specimens of which are 

 shown in figure 6. Sometimes, however, especially in the case of the 

 larvae of the first generation, some may spin themselves up within 

 a thin cocoon in the tips of the uprights, as shown in figure 7. Very 



