REPORT OF THE STATE ENTOMOLOGIST 1902 135 



seriously injured by the first application. It has been steadily 

 improving and now is in a vigorous condition, has developed a 

 large amount of new wood and bids fair in another year or two 

 to have a symmetric, good sized head. The twigs made a growth 

 of 8 to 12 inches during 1902 [pi. 3]. Tree 114, a pear of the 

 same variety, was sprayed in 1900 with undiluted crude petro- 

 leum but was not injured so much as no. 101. It was treated 

 last year with 20^ mechanical crude petroleum, which was 

 obtained from Titusville, and this year again with a 20^ petro- 

 leum emulsion. It is in vigorous condition and much better off 

 than two years ago [pi. 2]. Tree 69, a Howell pear, was treated 

 in 1900 with whale oil soap and petroleum and with a mechanical 

 emulsion of the latter in 1901 and 1902, and is now flourishing 

 [pi. 3]. The same is practically true of tree 66, a Bartlett 

 pear [pi. 2]. Tree 25 is a Beurre Bosc pear, which was very 

 badly infested in 1900. Trees 26 and 27 are KiefPer and tree 28 

 a seckel pear; the latter was also very badly infested in 1900. 

 At the end of 1900 young were reported as abundant on tree 28, 

 and the same was true at the end of 1901. The very bad condi- 

 tion of the tree at the end of 1902 is probably due to the fact 

 that it is in a corner which was rather difficult of access, and this 

 may have had some influence on its treatment in earlier years. 

 Tree 41 is a Crawford peach, and trees 42-45 and 47 are Old 

 Mixon peachtrees. Trees 42 and 43 were very badly infested 

 in the spring of 1900, but since then have developed little scale, 

 and all are in as good, if not better, condition than twro years 

 ago last spring, and several of them bore very fair crops of fruit 

 this year [pi. 5]. 



These cases go far toward showing that successive applica- 

 tions of crude petroleum, if carefully made, will not injure trees, 

 and that those which are very badly infested can be freed from 

 the scale to a considerable extent and brought into a profitable 

 bearing condition. 



Experiments at Highland. A 20^ mechanical crude petroleum 

 emulsion was applied Ap. 1 to 52 plumtrees, mostly Abundance 

 and a few Burbank. The trees had been covered with ice and 

 snow by a storm during the night and had just dried. The 

 weather at the time of spraying was sunny, rather cool, and con- 

 siderable wind was stirring, but the trees were well covered with 



