170 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



of the situation in time and naturally turned to the Department of 

 Entomology for help. 



The problem seemed a rather large one and I was surprised to find 

 how little definite data there really was to guide us in making an 

 estimate of the cost of spraying shade-trees, or to give a really ade- 

 quate idea of the kind of outfit to use, and the most economical and 

 effective methods of accomplishing the work. We have nothing 

 startling to offer in the way of new methods or apparatus, but we suc- 

 ceeded in spraying the trees with rather gratifying results in controlling 

 the beetle and in a fairly economical manner. We hope, however, 

 to improve the work during the coming season. 



The first question that presented itself, of course, was the matter 

 of apparatus. Our appropriation was not large and it, therefore, 

 became necessary to limit ourselves to reasonably inexpensive and 

 tried outfits. After much correspondence and several interviews 

 with agents, we decided to purchase a Hardie Power Sprayer with a 

 triplex pump, 3 H.P. engine, 200-gallon tank, 12-foot tower, two 

 leads of hose, each 100 feet long, and two extension poles, one 20 feet 

 long and the other 12 feet in length, and a Friend Hilly-Orchard outfit 

 with a 3| H.P. engine, California model pump, 8-foot tower and other 

 equipment like the former outfit. With these outfits, and both gave 

 eminent satisfaction, we were able at all times to maintain 175 to 200 

 pounds (and over) pressure. One man remained on the tower and 

 with his 20-foot extension pole and Bordeaux Nozzle was able to 

 reach, the tops of the very highest trees. The man on the ground 

 ran the engine, drove the team, and sprayed the lower branches. The 

 so-called foreman directed the work, mixed the solutions, attended to 

 breakdowns, climbed trees if necessary, and kept things going in 

 general. 



The first spraying was made from May 16 to May 25 and the second 

 from June 12 to June 22. 



We used 3 lbs. of paste arsenate of lead the first time over the trees 

 and 3| lbs. to 50 gallons of water the second time. 



A careful and detailed record of the actual cost of spraying 435 trees 

 was kept. Most of these trees were large and all of them stood near 

 the street and near our water supply. It cost $133.37 to spray these 

 trees once or 30.7c per tree. On the average each machine sprayed 

 36j trees per day of eight hours, or 4| trees per hour or a tree about 

 every 13f minutes. On an average we used approximately 18 J gallons 

 of liquid to each tree. 



A detailed example of a day's w^ork on the largest trees will give 

 even a better idea of the cost of spraying such trees. On June 19th 

 the two machines began on the largest elms on the Campus, namely, 



