English sparrows will fatten on the locusts while they last. There is no way known whereby the locust can be prevented from attacking trees and no way of reducing their injuries.

Map indicating the areas covered by the 17-year Locust. In 1902 they are due to appear over the territory west of a line drawn from Catawba Island to Portsmouth, except, possibly, in extreme southern Ohio.

We have heard much of the danger from fruit infested with San Jose scale, and, as is well known, this has led to international complications. While no question is likely to be settled by a single experiment, a series carried out relative to the probable danger from infestation of trees through this means will not be uninteresting. While all admit that there is a danger from this source, it is a fact that not a single instance can be cited where this has actually taken place.

On September 15, 1900, a number of peelings from badly infested apples were placed 4 inches from the base of an apple tree; six infested plums were placed similarly about the base of another apple tree; while two infested apples

were placed in the same manner about the base of a third apple tree; and peelings from infested apples were wound about the base of still another apple tree. Up to December 1, 1901, not a single scale has been found on any of these trees. On the same date, peelings from infested pears were placed about the base of a peach tree; six infested plums were piled about the base of a peach tree; infested pears were placed about the base of a peach tree; and infested apples were piled about the base of an apple tree. Here, again, not a single tree has been found infested, after the lapse of over a year. In order to determine the probability of living scale occurring on the fruit during the earlier part of the experiment, two infested windfall apples were placed under observation, October 9, 1900, and were inspected frequently to determine the condition of the San Jose scale infesting them. By this means we were able to determine the presence of living scale up to November 2, thus indicating that the trees were, some of them at least, exposed to infestation for 18 days. There is much to indicate a preference of the young scale for fruit, as where orchards are only slightly infested, the inspectors have found it far easier to detect the presence of a very few individuals by an examination of the fruit than by any other means. For this reason it would seem that young scale, born on various fruits, would be much less likely to wander about and spread themselves over the wood than they would to settle down on the fruit itself. In my last report, I spoke encouragingly of the possibility of introducing natural enemies of the San Jose scale from Japan. Since then an agent of the United States Department of Agriculture has visited that country and found this enemy, not in Japan, but northern China, and a few of the lady beetles (Chilocorus similis), a relative of our twice stabbed lady beetle, have been received in Washington. It is not thought advisable to divide this lot, but another consignment is on the way, and I hope by another year to be able to report the successful colonization of this insect in the orchards of Ohio.

Our treatment of infested premises, in carrying out the law relating to nursery and orchard inspection, has been such a campaign of education, in materials used, machinery and methods, that I have included the details in my Report on Entomology, because it seems to me that it more properly belongs there, rather than with the police work, like inspection. For the first time, I have had during the last year the opportunity of treating large areas instead of isolated trees or parts of rows; have been able to substitute square miles for square rods or yards, using the same mixtures, applied with the same machines and by the same men. We have used in this work some 20 tons of fish oil caustic potash soap, treating not only orchards of every variety of fruit growing in our climate, but also hundreds of city premises, upon which were growing almost every variety of ornamental shrub or tree that would thrive there. I have been obliged to use inexperienced men in some cases, under the direction, however, of those who have passed through a most thorough training, and in all of our work there has not been a single complaint of injury by this treatment. While the efficacy of this soap will depend upon the proficiency of those applying it, and this is true even in our own work, I feel 'sure that it is safe to place it in inexperienced hands, so far as the likelihood of

injury to vegetation is concerned; what we have been able to do with it, in the way of subjecting the San Jose scale I will tell you later on.

Ideal spraying, with the spray in the form of an impalpable mist, can only be carried out under cover, or during perfectly calm days; but we do not spray orchards under cover, and calm days are exceptional. The calyx and the buds do not wait on the wind, and the spraying must be done at the proper time, if we expect satisfactory results. With proper care in the execution of the work, one side of a tree may be treated while the wind is in one direction, and the other side when it is in a more favorable quarter, but the two sprayings must overlap, in order to be sure that nothing has been left untouched, which may be safely enough done with the fish oil soap mixture, but not always with petroleum mixtures. Ordinarily, one man to pump and one to handle each line of hose, is considered sufficient, but I find that another man is required to watch every movement of the men at the hose, in order to see that not a single twig or branch escapes treatment, and the whole gang had best be deaf and dumb to anything except their duties while thus engaged. We have largely overcome the adverse effects of low temperatures, as we can keep the soap mixtures hot in the tanks, and trouble is only experienced where we use long lines of hose in order to reach distant parts of premises on which we can not go with the heavy machinery, but where it is necessary to treat large trees distant from the street, in which case the mixture cools and thickens so that it clogs the nozzles unless kept in continual motion. Mr. J. C. Britton, my assistant in charge of this work, was able to overcome this by keeping all hose, extension rods and nozzles well cleaned and drained whenever not employed in the work. If the cessation was to be but momentary, the fluid was allowed to flow sufficiently to keep it in motion, and in moving from one place to another, both hose and nozzles were sometimes thrown into the tank. Where the mixture froze to the trees as fast as applied, and remained in that state for several days, its effect has been shown months afterward to have been entirely satisfactory. The influences of snow, rain and wind have yet to be overcome, and examinations made in October of premises treated during the previous winter have shown us that treatment under such conditions will not be likely to prove satisfactory. Much stress is sometimes placed on spraying one side of a tree while the wind is in one direction, and the other after the wind changes, but I find that among owners themselves, the other side is usually not sprayed at all, and we have adopted the practice of spraying a tree entirely and thoroughly after having begun, no matter what direction the wind may be, and have found it the most satisfactory.

The mechanical outfit for the work that we have been carrying on con sists of four Morrill & Morley Eclipse pumps, each mounted on a 200-gallon tank (Plate 2, Fig. 1), one Orleans steam spraying machine (Plate 2, Fig. 2), made by the Goulds, Seneca Falls, N. Y.; one small barrel sprayer, one knapsack sprayer and several hand sprayers, to be used where it is not practicable to use the larger machines. With the steamer we were able to not only heat the mixture in the tank belonging to the machine itself, but also in that of all the other tanks, by turning the steam directly into these tanks from the boiler of the steamer.

Fig. II.

Absolute extermination of the San Jose scale by a single treatment of the trees that it infested has never been contemplated, but I will now give you the results as found by repeated examinations, some of them as late as August 1st. We used, invariably, two pounds of this soap dissolved in each gallon of water.

Spraying began early in December, and our first work was not satisfactory, and was done over again, but, as the men became more proficient in the work and more familiar with the machines, there was vast improvement. In order that we might be able to learn just what we were accomplishing, I had different assistants go over and closely examine the trees treated at different times, and a concensus of their reports showed that we were killing from 95 per cent. of the San Jose scale upward to where we were unable to find any living scale at all on the trees. It was seldom that the percentage did not go above 98 per cent. This was the result of treatment in the various orchards during typical winter weather. In early spring our attention was devoted entirely to the peach orchards, along the lake shore between Toledo and Sandusky. Examinations made in orchards, treated during late April and early May, between July 22d and August 3d, resulted as follows, these examinations being made by two of my assistants:

In an orchard of 650 trees, 50 were examined and no scale found on any of them; 40 trees in another orchard examined and a single young scale found on three; 75 trees examined in another orchard and young found on 10, this being situated by the side of an orchard treated by owner with 10 per cent. crude petroleum mixture, every tree of which was infested, and the young observed established on the bark. Another orchard examined August 2, by two different individuals, failed to reveal a single living scale, and, still another that was very badly infested when treated by us, showed only an occasional living individual. One orchard near Toledo, treated by owner, showed 88 per cent. dead and the remainder living; in another, also treated by owner, 98 per cent. were dead.

A large number of experiments were carried out with different percentages of crude petroleum, both light and heavy, as we have both in Ohio, and they are about equally obtainable. It is not difficult to spray trees with crude petroleum and not injure them. It is also easy to spray trees with crude petroleum and kill the scale, but to accomplish both at the same time is decidedly difficult and seldom accomplished. To give the results obtained by our own experiments, in brief, it will suffice to say that anything below 20 per cent. crude petroleum has failed to destroy a sufficient percentage of the scale to warrant recommendation, and in the Station orchard at Wooster we have injured large peach trees with a 40 per cent. mechanical mixture, the present indications being that between 20 per cent. and 35 per cent. is likely to give the best results, if very carefully applied. We have killed peach trees with a 25 per cent. mechanical mixture, applied April 23rd to 26th, in the vicinity of Lakeside. So far, I am unable to distinguish any striking difference between the heavy and light oils, in effect, either upon the scale or the trees. With the apple it is different, and I believe that here we can apply a 50 per cent. crude petroleum, mechanical mixture, without injury during the winter, and, if the work is properly done, destroy a very large per cent. of the scale, probably as large as we can with the fish oil soap. The adverse effect will probably amount to no more than a temporary retardation of the foliage, at least this has been the experience in Ohio.