574 NEW JERSHV STATE AGRICULTURAL 



CRANBERRY INSECTS. 



An unusual amount of complaint was received fmm cranberry 

 growers of injur}- done by the yellow-head catcrpilhirs. It ai> 

 pears that on most bogs the water was drawn at the usual time 

 and rertowing to kill off insects was also done by date, rather 

 than according to the condition of the insects on the bogs. The 

 continuous cold of the water seems to have had the effect of 

 retarding the movements of the hibernating moths and they did 

 not become active until much later than usual. The result was, 

 that there seemed to be no hurry alxnit oviposition, and eggs were 

 not laid until the water had been drawn from the bogs. Some 

 eggs were laid along the edges where the reflowing was not com- 

 plete and on portions of the bogs where highland left vines above 

 the surface. The consequence was that even the first brood 

 l>ecame noticeable, while the second, which appeared just about 

 the time that the vines were setting fruit, spread over a very large 

 extent of territory and completely wiped out some of the bogs. 

 An estimate of fifty per cent, of fruit destroyed was made by a 

 grower whose crop ordinarily runs into the thousands of bushels 

 and almost everywhere some injury was done. Curiously encuigh 

 the Rlioj^obota. or black-liead caterpillar, was ahvost entirely 

 absent. 



After some discussion at the meeting of the Cranberry 

 Growers' Association, and after visiting some of the bogs in the 

 Pemberton district it was decided to carry on a series of experi- 

 ments which will tend to tix the hatching point for insects of this 

 character when covered b\- water. A great man}- iK.gs arc ver}^ 

 uneven and in the (k'e])er portions are full}- a week behind the 

 upper parts of the bog in starting after the water has been drawn 

 off. Where a grower depends upon late holding, it becomes im- 

 portant that he should know the temperature which must be 

 reached bv the water before he can hope to destroy the insects on 

 the vines. 



Grasshoppers were again complained of: but the evidence is 

 no more decisive as to the injury done than it has been in previous 

 years. However, it might he well in this connection to call atten- 

 tion to the fact that in Canada and in some .sections of the north- 

 western L'nited States, where grasshoppers are ( ften very 

 destructive it has been found that they have an abnormal fondness 

 for horse manure, they will readily leave green succulent plants 

 to feed upon it. Taking advantage of this, the farmers ha\c 

 made a mixture of horse maiun-e and Paris green and spread it in 



