UNITED STATES DEPARTMENT OF AGRICULTURE 
Wm BULLETIN No. 1093 fjgjf 
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iVashington, D. C. 
October 16, 1922 
THE GIPSY MOTH ON CRANBERRY BOGS. 
By Chaeles W. Minott, 
Gipsy Moth Assistant, Gipsy Moth and Bronm-tail Moth Investigations, 
Bureau of Entomology. 
CONTENTS. 
Pajre. 
Introduction 
Artificial cranberry bogs 
How bogs become infested with gipsy 
moths 
Wind dispersion of gipsy moth larvae- 
History 
Selection of a hog for experi- 
mental purposes 
Observations on wind dispersion. 
Description of traps 
Record of trap observations 
Feeding habits on cranberry foliage- 
Pa ee. 
Feeding habits on white oak foliage_ 10 
Injury by a given number of larvae- 11 
Mortality of first-stage larvae 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 rayages of 
this insect until 1913. About this time, howeyer, 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 cranbenw 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 Xew 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 
108485 c — 22 1 
