THE GIPSY MOTH OlST CRATTBEEEY 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. ^Yhen 

 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 recover5^ 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 i^articular 

 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 hilled hy a 

 thorough application of an arsenical poison^ and a com^prehensive 

 grasp of this fact is of vital importance to cranherry .growers for 

 efficient and economical control of this pest- on cranberry hogs. 



HOW TO DETECT AN INFESTATION. 



It is very difficult to detect first-stage gipsy-moth larvae on cran- 

 berry foliage owing to their habit of dropping to the surface of the 



