REPORT OF STATE HORTICULTURIST. 55 



long time and act as a protection to the raw wood. 



Cankers are the worst enemies we have at present; let us 

 keep the fact in mind. 



INSECTS INFESTING SHADE TREES. 



Borers. During the year the following borers have been 

 received at the office for identification : — Hickory bark borer, 

 Scolytus quadrispinosus (Say.), mottled willow borer, Cryptor- 

 hynchus lapatki (Linn.), elm borer, Saperda tradentata (Oliv.), 

 sugar maple borer, Plagionotns speciosus (Say.), pine bark 

 beetle, Touiiciis pini (Say.). 



The elm borer and maple borer have damaged great numbers 

 of our best shade trees and appear to increase greatly each 

 year. The badly infested trees should be cut and burned ; the 

 remainder thoroughly inspected and larvae killed where found. 

 It is shameful to lose our elms which are as beautiful as any 

 in the country and which go so far towards making our towns 

 attractive. 



Blm-leaf Aphid. Numbers of complaints were received from 

 the southern parts of the State during July, because of the 

 dampening of sidewalks under elm trees. This was due to the 

 work of the leaf aphid, occurring in large numbers. Both the 

 winged and wingless forms are very similar in color to the 

 leaves, making it difficult to distinguish them; they cling to the 

 leaves a considerable time, unless heavy rains occur. It is 

 hard to spray for them on large trees, but kerosene emulsion 

 has given good satisfaction on smaller ones. 



Blm-leaf Beetle. Even more damage was done to the elm 

 trees by this pest than during the previous season. The 

 infestation is greatest in York and Cumberland Counties, but 

 is increasing in the surrounding counties of Androscoggin, 

 Sagadahoc and Oxford. The defoliation of the tree in mid- 

 summer is a serious thing, preventing as it does the proper 

 function of the leaves. Occurring for a period of years, 

 such defoliation will cause death to the tree, and loss in 

 vigor when occurring occasionally. We have tried to impress 

 upon the owners of shade trees the importance of controlling 

 this pest before it has become so abundant as to weaken or 

 destroy a majority of the elms. Arsenate of lead has controlled 



