84 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
Table VIII indicates that a total of 580, or about 80 per cent, 
of the 685 eggs hatched, but only 6 worms (about 1 per cent) 
were able to penetrate through the lime-oil wash, enter the trees, and 
finally mature to moths. Former experiments (see Table IT) show a 
higher percentage of fertile eggs. A great discrepancy between the 
number of eggs which hatch and the worms which actually are able 
to enter the trees had been previously noticed. There is also a great 
mortality of larvee, as is evidenced by the number of worms which 
may be found in any tree and the number of moths that may mature 
later. The almost complete immunity of these trees is not, therefore, 
attributed entirely to the effectiveness of the lime-oil wash. 
Experiment No. 2.—The Wilson experiment was planned to deter- 
mine the danger of injury by applying crude oils directly and in combi- 
nation with lime to peach trees and also to determine the value of 
these oils as repellents or barriers against the entrance of borers. 
Crude oils have been applied directly to various fruit trees by orchard- 
ists in the Santa Clara Valley, and their application has proved fairly 
successful. Occasional injury has been reported. Peach and apricot, 
and especially the younger trees of these varieties, are very sensitive 
to oil, and it is believed that there must be more or less injury to other 
trees. The crude oil is undoubtedly a most effective barrier to keep 
newly hatched worms from entering the trees, and it also penetrates 
and draws many more mature worms out to their death. The oils, 
therefore, have a distinct and decided insecticidal effect against the 
borers. 
The Wilson experiment was arranged in three plats—Plat I, with 
10 trees (numbered 1 to 10, inclusive), Plat IJ, with 5 (numbered 
11 to 15), and Plat III, with 10 (Numbered 16 to 25). The earth was 
removed, the borers dug out, and the bark scraped, as in experi- 
ment No. 1. The various remedies were applied on June 20, 1908. 
Plat I was treated with the lime-oil mixture, which is recom- 
mended as formula No. 1. It was applied just as it was used in the 
previous experiment. Three gallons of the mixture were sufficient 
to treat the 10 trees. 
Plat IT was treated with a iight grade of pure crude oil known as 
Coalinga crude oil, 22° Baumé. This was likewise applied with a large 
brush and in similar way to the lime-oil mixture. One gallon was 
sufficient to treat these five trees. 
Plat III was treated with a heavier grade of oil known as Kern 
crude oil, or about 14 to 16° Baumé. This oil was cold and heavy and 
rather hard to apply. Three gallons were sufficient to treat the 10 
trees. 
The earth was immediately replaced around all of the trees after 
the treatment. 
