REPORT OF THE COMMISSIONERS OF FISHERIES, GAME AND FORESTS. 379 



.Means of distribution. This insect can be carried long distances on young trees 

 and it is undoubtedly in this way that it has succeeded in establishing itself at the 

 widely separated points named above. Its rapid dissemination throughout a city is 

 probably due to the agency of birds, particularly the English sparrow. There 

 appears to be no other adequate explanation of the general occurrence of this pest 

 throughout Albany and Troy. It is also possible that the young falling with the 

 leaves are blown to new localities and succeed in establishing themselves on unin- 

 fested trees. This latter means is so uncertain, compared with birds which habitu- 

 ally fly from tree to tree, that it cannot be considered as a source of much danger. 



Natural enemies. It is very probable that a number of lady bugs in both 

 adult and larval condition feed to some extent on the young of this insect. The 

 two spotted lady bug, Adalia bipunctata Linn., has been seen in considerable num- 

 bers about infested trees in Albany but it was not observed feeding upon the pest. 

 Many flies and other insects are attracted to infested limbs by the abundant honey 

 dew. 



Remedies. Spraying with a contact insecticide, kerosene emulsion or a whale oil 

 soap solution is probably the best remedy for this insect. This treatment will be 

 most effective if given early in the spring just after the hibernated forms have molted 

 or soon after the young make their appearance. A solution four times the normal 

 strength is necessary to kill the insects late in the fall. Spraying the infested trees in 

 early spring with a 20 per cent mechanical emulsion of crude petroleum would proba- 

 bly prove very effective and not injure the elms. It would hardly do to apply this to 

 trees where a little oil would be objectionable as the petroleum remains on the bark 

 for a considerable period. Small trees have been effectually cleaned by going over 

 them with a stiff brush and this would be more effective were it done in early spring 

 and the brush kept well wetted with kerosene emulsion or whale oil soap solution. 

 A good stream of cold water would be much better than nothing and when directed 

 against the masses of females could hardly fail to wash off large numbers. This 

 latter method is advisable only where a good head of water and hose is convenient. 



