REPORT OF THE STATE ENTOMOLOGIST I9OO 985 



81, globe peach 12 feet high, were but moderately infested with the 

 San Jose scale. Tree 102, a beurre bosc pear 10 feet high, and tree 103 

 an Idaho pear 13 feet high, were respectively, moderately and very badly 

 infested with the scale. The buds had started a little when these trees 

 were treated. 



Ap. 19. Tree 102 was subjected to the action of the gas from 10.47- 

 11.23 a. m. The day was bright. 



Ap. 20. Tree 80 was fumigated from 11.58 a.m. to 12.23 P» m «> while 

 the sun was partly obscured. Through accident not all the cyanid was 

 turned into the acid. 



Tree 81 was fumigated from 11.10-11.45 a.m., and tree 103 from 

 10.20-10.57 a. m. The sun was bright during both of these treatments. 

 Equal amounts of cyanid and sulphuric acid and thrice the amount of 

 water were used in fumigating trees 81, 102 and 103. 



May 11. Trees 80 and 81 will apparently develop a goodly number 

 of blossoms, and the leaves are starting well. There will be few blossoms 

 on tree 103. The leaves are nearly extended. 



May 14. The leaves and blossoms on trees 80 and 81 are starting 

 well, the latter being abundant. The leaves are pretty well developed 

 and rather abundant on trees 102 and 103, and on the former blossoms 

 are somewhat scarce, but they are numerous on the latter. 



July 2. No living young scales can be found on trees 80 and 103 and 

 but very few on trees 81 and 102. 



Aug. 3. No living young scales are found on any of these trees at 

 this time. 



Sep. 7. Very few living young are found on trees 80 and 81, none, 

 on tree 102 and but few on tree 103. 



Conclusions 



Kerosene. The experiments with kerosene show beyond question that 

 neither a 20 nor a 25% mechanical kerosene emulsion can be relied on 

 to kill dormant San Jose scales in this latitude, though either can be used 

 in early spring with comparative safety to the tree. A summer applica- 

 tion of a 10% mechanical kerosene emulsion does not injure the trees 

 appreciably, and is a valuable aid in keeping the pest in check, but the 

 treatment should be repeated every 10 days, beginning about June 15 

 and continuing into September, in order to obtain the best results. The 

 experiments with undiluted kerosene are hardly satisfactory, for the reason 

 that few trees were involved, and these were in bad condition on account 

 of scale injury. The oil did not cause as much injury as was expected, 



