REPORT OF THE STATE ENTOMOLOGIST I9OO 975 



and 42-46. The young are rather abundant on trees 41 and 47, and are 

 numerous on tree 15, specially on the side next tree 14, which was treated 

 with 20 % kerosene emulsion. The young are abundant on trees 22 and 

 28, both of which were very badly infested at the start. 



A most interesting sight is the hosts of young present on a tree set in 

 between trees 7 and 8 after the orchard had been sprayed. The trunk 

 is almost white with young in places, showing the condition the other 

 trees might have been in but for the treatment. 



Oct. 25. There are naturally more insects on these trees than there 

 were Sep. 7. For example, the young are numerous on some of the 

 twigs of tree 28, but, compared with the kerosene-treated trees, their con- 

 dition is most excellent. 



Experimaits with 25 % mechanical e??iulsion. The condition of the 

 trees at the time of spraying, Ap. n, was as follows. Tree 55, a beurre 

 bosc pear about 10 feet high, was badly infested with the San Jose scale. 

 Trees 56-61, all seckel pear, were about 14 feet high with the exception of 

 trees 57 and 58, which were about 10 feet high, and were all badly infested 

 with the scale except tree 56, which was moderately infested. Trees 78, 

 79, globe peach trees, were about 14 feet high. The former was badly 

 and the latter moderately infested with the scale. The spraying varied 

 only from the preceding experiment in the per cent of petroleum. 



Ap. 19. The petroleum is very apparent on trees 55-61, 78 and 79, 

 and the buds are starting on trees 56-68, 78 and 79. 



May 14. Tree 55 has its leaves pretty well out and only a few blos- 

 soms. The leaves of trees 56-61 are pretty well out and abundant, ex- 

 cept on the more badly infested trees, 58-61, tree 61 being specially bad. 

 Trees 78 .and 79 have abundant leaves about half out and numerous 

 blossoms. 



May 28. The leaves of tree 61 are rather thin, but this evidently is 

 due to the abundance of the scale, as the foliage of trees 55-60 is much 

 thicker, and they are fortunate in the possession of much less scale. 



July 2. No living young are found on trees 55-57 and but few on 

 trees 58-61. They are rather numerous on trees 78 and 79. 



Aug. 3. There are very few or no living young on trees 55-57, 78 and 

 79 and comparatively few on trees 58-60, and on tree 61 they are some- 

 what abundant. This tree was in an extremely bad state to start* with. 



Sep. 7. Very few or no living young on trees 55-57, 78 and 79. Scales 

 are rather abundant on trees 58-61. 



Oct. 25. The conditions are practically the same as obtain in those 

 sprayed with the 20 % emulsion. 



