42 



few as compared with their numbers at this time last year. Where, the 

 fruit was much pitted and scarred by the scale last year uot one has 

 been seen upon a pear thus far this season. 



In all, the experiment is thoroughly satisfactory, in that it demon- 

 strates by actual trial that this method can be used in our largest bear- 

 ing orchards, even under the most adverse conditions, with excellent 

 results. 



I do not recommend the adoption of this method to the average fruit 

 grower; it must be in the hands of an expert, thoroughly familiar with 

 the process in every detail and the conditions which insure success. 

 Where the scale is confined to a few trees under 15 feet in height it is 

 the most effective remedy for its suppression. 



The gas can also be used in the spring in peach, plum, and apple 

 orchards, after the buds have begun to unfold. A block of one hun- 

 dred six-year old plum trees at Annapolis Junction was fumigated 

 March 17 and 18, 1898, and up to the present time not a living scale has 

 been found upon any trees, except those sprayed with 50 and 100 per 

 cent gasolene. The trees in this orchard were very badly infested, the 

 most of them being so literally covered it was impossible to see the 

 bark at any point on the trunk and larger branches. 



Other experiments were conducted in scale infested bearing orchards 

 in May, June, and July, the results of which can not be finally reported 

 at this time, except that no living scales have been found upon any of 

 the fumigated trees. 



Much encouraged by the outcome of these experiments, I have 

 applied this method to other insects. Experiments were conducted 

 upon the Euonymus scale (Chionaspis euonymi) December 16, 1897, 

 with most excellent results. The shrubs were very large, some of them 

 being 10 to 12 feet in height and from 6 to 8 feet in diameter. They 

 were literally covered with the scale, and seven of them had been killed, 

 while seven others were still alive. 



The treatment was the same as used in the orchard, and not a living 

 insect has been detected this season. 



The apple-leaf aphis [Aphis mail), being very bad in Maryland in one- 

 year, two-year, and three-year old orchards this spring, I began some 

 experiments to see if this method could not be applied for its destruc- 

 tion, as it was practically impossible to reach the insects with any 

 spray on account of the curled and folded leaves. Trees covered with 

 tents iu the direct sunshine (95° F.), and fumigated for five minutes, 

 were not injured in the least, and all the lice were killed. 



Two-year peach trees badly infested with the black peach aphis (A. 

 pnmicola) were treated and exposed in the same manner with identi- 

 cally the same results. 



Three-year and four-year old pear and cherry trees, being defoliated 

 by the slug, were successfully treated ; but it required a longer expo- 

 sure. Ten minutes killed all insects, but the foliage was also injured, 

 and I would not recommend its use. 



