14 



NEW YORK STATE M.USEUM 



($30_$5o) is much less. It is extremely desirable, where conditions 

 permit, for a community to provide not only for the spraying of the 

 street trees, but also to arrange for the care of those on private 

 grounds at a nominal cost. 



The full-grown larvae crawl down the trunks in great num- 

 bers and the golden yellow pupae may be found in abundance in 

 crevices in the bark and on the ground about the tree. A good 

 proportion of the insects can be forced to take refuge on the 

 ground by scraping off the rough bark, thus depriving them of 

 shelters upon the tree. Large numbers can then be killed when 

 assembled about the base of the tree by spraying them with a 

 contact insecticide such as kerosene emulsion, whale oil soap 

 solution or even by pouring boiling water on them. The 

 grubs should be destroyed in the manner indicated every five 

 days so long as the pests are seen in numbers, in order to secure 

 the best results. This method of fighting the pest is advisable 

 only when it is impossible to employ the more satisfactory 

 arsenical sprays. Bands of tar, sticky Hy paper, cotton batting, 

 etc., while they do no harm, can not be considered of much value 

 in keeping the elm leaf beetle under control. The relatively few 

 grubs caught on a sticky band are but a drop in the bucket com- 

 pared with the masses which complete their transformations 

 either above or below. It is worse than useless to attempt to 

 control this or any other insect by boring a hole in the trunk of 

 a tree and inserting therein compounds of any nature. The tree 

 is weakened and unless the chemical be powerful enough to kill 

 it, the insects are not affected. 



White-marked tussock moth. 



Hemerocampa leucostigma Abb. & Sm. 

 This insect, preeminently a pest on city and village trees, 

 occasionally proves a veritable scourge over considerable areas. 

 Some cities appear to be more afflicted in this way than others. 

 The summer of 1906 was marked by extensive depredations in 

 a number of cities and villages throughout the State, thus dupli- 

 cating the experience of 1898. It will therefore be seen that seri- 

 ous injuries by this caterpillar are more or less periodic. This 

 is to be explained by the fact that the species has a number of 

 natural enemies which assist materially in keeping it under con- 

 trol. The destructive outbreaks are examples of what might 

 occur annually w^ere there no parasites to check the work of this 



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