UNITED STATES DEPARTMENT OF AGRICULTURE 



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SWS''"^^U 



Washington, D. C. 



October 16, 1922 



THE GIPSY MOTH ON CRANBERRY BOGS. 



By Charles W. Minott, 



Oipsy Moth Assistant, Gipsy Moth and Brovyn-tail Moth Investigations, 

 Bureau of Entomology. 



CONTENTS. 



Pa KG. 



Introduction 1 



Artificial cranberry bogs 2 



How bogs become infested with gipsy 



motlis. 2 



Wind dispersion of gipsy moth, larvae- 3 



History 3 



Selection of a hog for experi- 

 mental purposes 3 



Obsei-vatlons on wind dispersion. 4 



Description of traps 5 



Record of trap observations 6 



Feeding habits on cranberry foliage_ 9 



Page. 



Feeding habits on white oak foliage_ 10 



Injury by a given number of larv8e_ 11 



Mortality of flrst-stage larvse 12 



Recovery of cranberry vines from 



gipsy moth feeding 13 



Methods of control 13 



How to detect an infestation __ 13 



Control on wet bogs 14 



Control on dry bogs 16 



Control on uplands 17 



Summary 19 



INTRODUCTION. 



While the gipsy moth {Porthetria dispar L.) has been in Mas- 

 sachusetts since 1868, that section of the State in which the cran- 

 berry industry is established was nearly immune from the ravages of 

 this insect until 1913. About this time, however, owing to favorable 

 conditions, the infestation increased very rapidly in the southeastern 

 part of the State, and occasional complaints were heard regarding 

 injury to cranberry bogs in certain sections of Bristol, Barnstable, 

 and Plymouth Counties. These conditions, and the importance of 

 the cranberry industry, were sufficient causes to warrant a study of 

 the habits of the gipsy moth on this new food plant. Under the 

 direction of A. F. Burgess, in charge of moth work in New Eng- 

 land, the writer began a study of the problem in 1916, the results 

 of which are recorded in this bulletin, together with suggestions in 



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