kerosene of 150 test evaporates rapidly, and 

 leaves but little signs of having been applied. 

 April 25, 1882 One tree dead; the other not 

 dead but nearly so. October 14, 1882 Ex- 

 animation showed trees to be dead. 



No. 18. Kerosene, same brand. July 27, 1881 

 Applied upon a pear tree by spray atomizer, 

 which produced a very fine mist only. Aug- 

 ust 2, 1881 The same effects produced as in 

 No. 17; scale appeared to be entirely destroyed; 

 no apparent effect upon tree or foliage. April 

 25, 1S82 Tree not dead, but with many scales 

 upon it. October 14, 1882 Old wood 

 dead, but new wood from near the ground. 



No. 19. Gasoline. July 27, 1881 Applied 

 upon pear tree by heavy syringe spray thor- 

 oughly over the tree and foliage. August 2, 

 1881 Not effectual in destroying the scale; too 

 volatile; many of the insects killed, but a large 

 portion unaffected; no apparent effect upon the 

 tree or foliage at that time; on this tree the 

 young male scales just hatched out were found 

 crawling about. April 25, 1882 The tree has 

 been almost killed by the scale infesting it. 

 October 14, 1882 Tree still alive, with some 

 si<l6 upon it. 



No. 20. Gasoline. July 27, 1881 Applied 

 upon pear tree by the spray atomizer. August 

 2d Result same as the preceding. October 14, 

 1882 This tree did not suffer from the effects 

 of the < ^plication, but this season has made a 

 vigorous growth of new wood quite clean from 

 scale. The foregoing applications of kerosene 

 and gasoline were made in full strength. 



Whale Oil Soap and Sulphur. 



No. 21. Whale oil soap and sulphur mixt- 

 ure 1 lb., water 1 gal. June 23, 1881 Ap- 

 plied by spray over pear tree, covering foliage 

 and fruit thoroughly. July 23d Scale killed; 

 tree gaining in health; green layer of bark be- 

 ing restored; fruit greatly improved in appear- 

 ance. August 2, 1881 Tree still improving, 

 also fruit. April 28, 1882 Tree very healthy 

 and appears clean from scale; green layer of 

 bark being fully restored, and parts of the tree 

 that were nearly killed by the scale are form- 

 ing new bark rapidly; the tree has a very fine 

 top of new growth. October 14, 1882 The 

 tree has grown very thriftily through the sea- 

 son and the wood is all very healthy; some 

 scale are found upon the tree, however. These 

 trees are in an orchard badly infested, and it is 

 to be expected that the insects will return. 

 This wash is an effectual summer wash, and 

 where there is any scale present should be used 

 in the strength here given, as a wash of one- 

 half the strength has proven ineffectual. 



Soft Soap and Sulphur. 



No. 22. Soft soap, one pound; sulphur, one 

 pound; tobacco, one pound; water, three gal- 

 lons. July 5, 1881 Applied upon two trees by 

 spray, covering trees, foliage and fruit thor- 

 oughly. July 23, 1881 Seemed quite effectual 

 at the time; many scale destroyed, but not all; 

 trees, not affected by the wash; fruit improved in 

 appearance. Subsequent observations, however, 

 showed that but little was accomplished in 

 destroying the scale. October 14, 1882 This 

 tree shows an abundance of live scale in all 

 stages of growth. This wash was used with good 

 effect in another orchard, June 1, 1881, on a 



Fellenberg prune tree, clearing it from scale, 

 which, up to this time, have not returned. 



No. 23. Soft soap, one pound; sulphur, 1 

 pound; water, three gallons. 



No. 24. Soft soap, 1 pound; water, 3 gallons; 

 The two washes named above were applied 

 June 23, 1881, and with no effect, neither 

 has it shown any result this season. 



Whale Oil Mixture. 



No. 25. Whale oil, one pint; kerosene, one 

 pint; borax, one ounce; water, one gallon. June 

 23, 1881 Applied by spray to a pear tree at 

 the different dates in 1881; the effect has been 

 observed ; it has been apparent that the oil is 

 decidedly injurious to the tree, applied in this 

 manner or at this time; it is therefore not 

 recommended. Applied to another tree in one- 

 fifth the strength above given; it has no effect 

 upon either scale or tree. April 25, 1882 The 

 tree first treated is nearly dead; but, however, 

 having the top cut off, new wood is coming 

 along; scale appears to be destroyed. October 

 14, 1882 The old wood is dead; the sickly 

 growth of new wood springing out from the 

 lower portion of the tree shows some scale. 



Carbolic Acid. 



No. 26. Carbolic acid, three ozs.j water, two gal- 

 lons. June 23, 1881 Applied by spray upon a 

 pear tree badly infested with scale. June 27, 

 1881 Failed entirely. This tree afforded a con- 

 stant succession of insects in all stages of devel- 

 opment, both male and female. From it some 

 of our most interesting studies were made; we 

 repeat it as it appeared at each visit on that 

 date (June 27, 1881); we found the male insect 

 under its scale partially developed, with wing 

 pads, but wings not yet out. July 2d Found 

 plenty of winged males of the second brood fly- 

 ing and crawling about. July 23d Tree was 

 covered with young female scale insects of the 

 second brood crawling, and with a few of them 

 just located and commencing to be 

 covered with their scale. July 25th A 

 few of the winged male still found; 

 bark scraped clean on this date was in two 

 days covered with young scale and with a slight 

 formation of scale over them. Aug. 2d Tree 

 entirely covered with young scale on this date; 

 two or three winged males were found. April 

 25, 1882 Tree almost dead from effects of 

 scale; top dead and removed and a few feeble 

 shoots coming forth. October 14, 1882 Shoots 

 have grown from the trnnk of the tree to some 

 extent, but the whole having been so seriously 

 infested the tree is considered worthless. 



The entire orchard in which these trees are 

 situated, other than the ones experimented on, 

 from 8 to 26 were washed this past winter with 

 a very low grade of coal oil called "tree wash;" 

 the result is not satisfactory; the owner 

 tells mej(0ctober 14, 1882) that he is satisfied 

 that the oil has seriously injured his trees. 



San Jose. October 25. 1882. 



Experiments with Steam. 



It was at one time thought that steam might 

 be effectually applied for the extermination of 

 insect pests upon trees. In the summer of 1881 

 a test of this agent was made in an orchard near 

 San Jose. A large tent was made to hang upon 

 a frame, which could be run on either side of. 



