246 BOAKD OF AGRICULTURE. [Pub. Doc. 



Where large numbers of elms are grown in compact plots the 

 insect appears to find most favorable conditions for multipli- 

 cation, and it is a matter of the writer's personal observation 

 that many of the large nurseries in this State Avhere elms are 

 thus grown are abundantly supplied with the insect. The 

 elm bark louse is now generally distributed throughout 

 Massachusetts, and may be considered a serious pest, since 

 from the insidious nature of its attack it often escapes notice 

 until the infested trees are injured beyond recovery. The 

 presence of the insect is often indicated by an early yellow- 

 ing of the foliage on the infested branches and the gradual 

 death of the latter from the tip downward toward the trunk. 



Remedies. 



The damage from the . imported elm bark louse is a long 

 time in appearing and considerable time is required for the 

 tree to recuperate from the injury. Badly infested trees 

 should be pruned of all dead and dying 1)ranches in the fall, 

 the wounds being covered with thick oil paint or gas tar. 

 At the same time the trunk and branches should be scrubbed 

 with strong kerosene emulsion, made by dissolving one-half 

 pound hard soap in two quarts of hot water and stirring into 

 the mixture while hot one gallon of kerosene oil. Dilute the 

 emulsion with three parts of water and scrub the trunks and 

 branches with this mixture, using a stiff brush. The follow- 

 ing spring, top-dress the ground beneath the trees with good 

 stable manure or with nitrate of soda, and later, in July, 

 spray the foliage thoroughly with kerosene emulsion, diluted 

 one part to nine of water. The recommendations given 

 above apply to cases where the trees have been seriously 

 injured. Where the insects occur in moderate numbers, 

 both the scrubbing and spraying may be done in July with 

 satisfactory results. Often a thorough spraying at this time 

 will suffice to destroy the greater part of the insects. 



To show how cheaply this work may be done where a large 

 number of trees are to be treated, the following account of 

 tlie treatment of 3,000 young elms in Manning's nursery at 

 Reading, Mass., may be of interest: In May, 1896, Mr. 

 Manning found that the elm bark louse had multiplied to 

 such an extent as to seriously infest a large part of his stock 



