EXPERIMENT STATION EEPORT. 561 



anything else save poplar, and the silver or soft maples were more 

 hardly dealt with than any other variety. Injury became obvious 

 quite early in the season, and the caterpillars were so unpleasantly 

 conspicuous in many 

 places that public atten- 

 tion was drawn to them 

 and the question of 

 abatement arose. In 

 some places where or- 

 ganization existed spray- 

 ing was resorted to, 



and while at no point caterpillar of the Tussock Moth. After Riley. 



were the insects entirely 



cleaned out, they were, at any rate, kept in severe check. At most 

 places, however, the first brood matured, and when the cocoons and 

 egg masses appeared attempts were made to gather and destroy them. 

 The experiment made in Newark of purchasing egg masses is elsewhere 

 referred to, and points out a practical method of dealing with the 

 insect in midsummer and preventing or materially checking the de- 

 velopment of a second brood, or, where no second brood occurs, of les- 

 sening the supply for the season following. 



On this latter point it was found that the State is divided into two 

 rather well-marked faunal regions. Egg masses obtained at Riverton 

 during the early days of August hatched promptly, and the second 

 brood of caterpillars was large. But from dozens of egg masses col- 

 lected at New Brunswick only a scant hatching was obtained : by far 

 the greater number of masses remained undeveloped, although the 

 eggs, on examination of the undeveloped masses, proved entirely sound. 

 The prompt collection of midsummer egg masses is therefore a much 

 more important matter in the counties south of the red shale line than 

 it is at New Brunswick or points further north, where the second 

 brood is fragmentary or non-existent. 



At Newark and in the immediately surrounding towns a curious 

 condition exists. In some parts of the city all the eggs hatched and 

 there was a full second brood ; in others none hatched, and the late 

 brood was altogether absent. In the suburbs, anywhere from none 

 to 75 per cent, of the eggs hatched, and even the eggs of one cluster 

 varied. In some clusters every egg was hatched; in others a varying 

 percentage developed ; in yet others all the eggs remained sound. Part 



36 



