57G 



XEW JERSEY AGEICULTURAL COLLEGE 



THE CRANBERRY FRUIT-WORM. 



Mincola vaccinii Kiley. 



This insect, ordinarily much more plentiful in Massachusetts than 

 in New Jersey, was unusually abundant on our bogs this year, and 

 a brief review of our present knowledge of the best methods of dealing 

 with it would seem to be in place. 



During the two years last past a series of systematic observations 

 and experiments have been made by Mr. Henry J. Thayer, of Boston, 

 Mass., and the results of these he has been kind enough to 

 communicate to me. It appears now that the life period of some of 

 the stages is very much longer than had been believed and the develop- 

 ment is much more irregular. It appears, also, that while insecticides 

 are entirely useless to lessen injury, a proper handling of the water is 

 very effective, and Mr. Thayer has reduced the injury done on his 

 bogs to a very small percentage. 



The adult moths appear on the bogs, in ordinary seasons, early in 

 July, when the fruit is just beginning to set, but isolated examples 



are on the wing much earlier, Mr. 

 Thaver's breeding records show- 

 ing the first example June 16th. 

 They remain on the bogs through- 

 out July and probably most of 

 August, some hibernating larvae 

 yet remaining unchanged to pupae 

 in the early days of that month. 

 The heavy flight, however, is prob- 

 abl}^ over soon after the middle 

 of July, when young larvas are 

 already quite plentiful. That the 

 development is very uneven is 

 shown by the fact that in early September caterpillars are sometimes 

 found in all stages of growth, but this, again, varied with the season, 

 for practically none was found in the berries September 23d, when I 

 visited Mr. Thayer's bogs. 



The moth, with wings expanded, measures about three-fourths of an 

 inch, and is of a glistening ash-gray, mottled with white and blackish ; 

 the fore-wings narrower and rolled up, so as to cover the hind-wings 



'^^-^ 



Fig. 38. 



Cranberry Fiuit-worm : a, herry showing egg ; 



b, c, egg ; d, caterpiUar ; e.f, pupa ; g, 



cocoon ; h, moth : all save a and 



g enlarged. After Riley. 



