THE GIPSY MOTH ON CRANBERRY BOGS. 13 
RECOVERY OF CRANBERRY VINES FROM GIPSY MOTH FEEDING. 
The soils of cranberry bogs are bound to vary in different bogs, 
owing to location, character of the peat constituents, and variation 
in grading. Often it is necessary to remove nearly all the peat in 
some sections of a bog in order to get the proper grade. When 
such conditions occur there is an uneven distribution of water ; con- 
sequently the resulting crop will vary and the recovery of vines after 
injury will vary. 
Muddy Pond Bog would be rated as a dry bog during the whole 
period that observations have been carried on. Whenever defoli- 
ation has occurred it has meant the loss of a crop for two years. 
After the buds or new growth were destroyed the vines would make 
a second growth from dormant buds, but would not form fruit buds. 
The second year, if no feeding occurred, the vines would make a 
normal growth and develop strong fruit buds, which would produce 
a heavy crop of berries the second year from defoliation, provided no 
climatic or insect injury prevented. Observations on wet bogs with 
a controllable water supply have shown that when the vines suffer 
the loss of the terminal fruit bud or of the later new growth, they 
usually make quick recovery, putting forth a strong second growth, 
and develop vigorous fruit buds. In a number of such instances a 
heavy crop of fruit has been produced the year following. 
METHODS OF CONTROL. 
The first requisite in the fight against a noxious insect is an accu- 
rate knowledge of its life history and all that pertains to its increase 
or decrease in the field. It is usually found that at some particular 
stage of its life it is more vulnerable than at any other. After this 
stage has been determined, the most effectual measure for control or 
extermination can be employed 
Observations on the mortality of first-stage gipsy moth caterpillars 
have demonstrated the fact that soon after hatching from the pro- 
tective egg mass they are very susceptible to injury by cold, and 
large numbers are destroyed at this time; particularly is this true 
should beating rains occur accompanied by low temperatures. At 
this stage of their development they are most readily killed by a 
thorough application of an arsenical poison, and a comprehensive 
grasp of this fact is of. vital importance to cranberry groivers for 
efficient and economical control of this pest on cranberry bogs. 
HOW TO DETECT AN INFESTATION. 
It is very difficult to detect first-stage gipsy-moth larva? on cran- 
berry foliage owing to their habit of dropping to the surface of the 
