THE BLACKHEAD FIREWOEM OF CRANBERRY. 5 



origin of the cuttings used furnishes convincing evidence that large 

 numbers of the eggs of this pest were brought into this region on the 

 leaves of cuttings from bogs in these three States. These cuttings, 

 principally from Massachusetts bogs, were used extensively in plant- 

 ing a large number of bogs set out in Washington and Oregon between 

 1912 and 1915, which was about the time the blackhead fireworm 

 became a pest of considerable importance in the regions from which 

 these cuttings were imported. 



After the newly planted bogs had made sufficient growth, it was 

 the practice to mow them and use the cuttings thus obtained to plant 

 other areas, as these cuttings could, of course, be obtained at less cost 

 and in better condition than those from the East. So, helped in this 

 way, the blackhead fireworm spread over practically the entire region. 

 Once established on a bog it was a matter of only a few seasons until 

 this pest had overrun nearly every part of it and caused considerable 

 damage almost before the owner was aware of its presence. 



DISTRIBUTION. 



The blackhead fireworm is found on nearly every cranberry bog 



on the Pacific coast. It has long been a pest of the cranberry in New 



Jersey, Massachusetts, and Wisconsin, where it now causes as much 



damage as any other cranberry pest and often more. According to 



Fernald,* it has also been found on the cranberry in New York and 



California. 



FOOD PLANTS. 



Numerous small larvse resembling very closely in appearance those 

 of Rhopohota naevana were found feeding on some common bog 

 plants, such as " buck brush " ^ and " sweet gale." ^ None of these 

 proved to be the blackhead fireworm; and, so far as known on the 

 Pacific coast, Rhopohota naevana feeds only on the cranberry, both 

 native "^ and cultivated.^ 



DESTRUCTIVENESS. 



The injury to the cranberry by the blackhead fireworm is caused 

 by the feeding of the larvae, or worms, on the buds, foliage, blos- 

 soms, and fruit throughout the growing season. It is. very charac- 

 teristic and quite unmistakable; there is no other pest of the cran- 

 berry on the Pacific coast the work of which is similar in all respects 



*Pernald, C. H. A Synonymical Catalogue of the Described Tortricidae of North 

 America North of Mexico. In Trans. Amer. Ent. Soc, v. 10, p. 48. 1882. 



° Specimens of this plant were identified as Spiraea douglasii by Dr. F. L,. Pickett, of 

 the Washington Agricultural Experiment Station. 



^ Also identified by Dr. Pickett as Myrica gale. " It belongs to the bayberry group." 



^ Oxijcoccus (oocycoccus) intermedins, tlae common \Yestern cranberry. 



^ Oxyoo'ccus macrocarpus, the common cultivated cranberry. 



