154 



experiments which had been instituted by Mr. Hedges had been unsuc- 

 ces.sful ; that tlie insect affected pear, peach, pkini, apple, currant, rose, 

 quince, gooseberry and raspberry, and that it must have been intro- 

 duced several years previously, presumably upon nursery stock, and 

 probably (in the light of what we have more recently ascertained) upon 

 currants purchased from a New Jersey firm. 



Inasmuch as the insect was found to be so limited, and to occur upon 

 such a comparatively small number of trees, and they of small size, it 

 was decided to postpone treatment until the early spring of 1894. 

 In order to make a siugle treatment absolutely effective, tents for fumi- 

 gating Avere constructed, aiul Mr. Coquillett, who was already expe- 

 rienced in the api)licatiou of the gas process, was seut to Charlottes- 

 ville early in March to conduct the operation. In the meantime Prof. 

 Eiley had consulted personally with the board of agriculture of the 

 State, and an arrangement had been made to conduct the operation 

 conjointly, as to the expense, the State Board furnishing the labor, 

 and the Department of Agriculture furnishing the apparatus and Mr. 

 Coquillett's services as overseer. The tents were constructed of eight- 

 ounce duck, and were made in the form of an octagonal sheet. Two of 

 them measured 44 feet in diameter, and two 28 feet. They were oiled 

 with boiled linseed oil. On trees of six feet and under the tents were 

 placed over by hand; on larger trees they were hauled over by means 

 of a single upright post with a pulley arrangement. The operation 

 was unique in the fact that, for the first time, the tents were to be put 

 over leafless trees, and it was expected that some trouble would result 

 from the breakage of the limbs ; but with the exception of a few large 

 pear trees, the branches of which were somewhat rigid and brittle, 

 very little trouble was experienced. Each tree was fumigated for half 

 an hour with hydrocyanic acid gas, made in the usual way. The trees 

 were in a semidormant state, although some of them Imd put forth a 

 few leaves, and a few peach trees were in full blossom, but none of the 

 trees were injured by the gas. So far as I am at present informed, all 

 the scale insects were destroyed. 



During March, 1894, the proprietor of a large peach orchard at liiver- 

 side, Charles County, Md., brought to the office peach twigs covered 

 with the pernicious scale. Prof. IJiley was in the AVest ludies at the 

 time, and I immediately sent an assistant, Mr. Marlatt, to visit the 

 orchard. It was found that the farm is situated on the river front, and 

 comprises about 288 acres, of which 20 are planted to orchard. In the 

 orchard are 2,000 peach trees, with 250 apple trees intermixed with 

 them. The older portion of the orchard was j)lanted in 1882, in a strip 

 along the river front. In the fall of 1887, 500 peach trees were planted 

 on the western side of this strip, separated from it only by a low hedge. 

 This stock was obtained from a Kew Jersey nurserj^, and it is believed 

 that upon it the scale was introduced. Later (1891) a younger orchard 

 was planted still farther on the west and adjoining the 1887 orchard. 



