222 THE MONTHLY BULLETIN. 



lias ever been done on walnut trees, and although there was compar- 

 atively little noticeable result against the blight, there was a decided 

 tendency to control the walnut aphis. The results of this work have 

 been published by the University in Circular No. 107. They were 

 thought of sufficient value for the University to push the matter further 

 tliis season, and as a result quite an acreage is being sprayed in Santa 

 Barbara County, Ventura County, and Orange County. 



Until recently the life history of this insect has not been definitely 

 known. Mr. W. M. Davidson, of the Bureau of Entomology, has I'e- 

 cently worked this out to completion. His findings are at present in 

 press at AVashington, and will soon be available. 



The following notes taken by the writer in Ventura County may be 

 of interest along this line : Eggs, small and flat without stem of any 

 sort; rather a dull black in color; usually laid singly on young buds, 

 or in crevices on larger branches ; occasionally found in groups of 

 from three to seven. In 1912 careful inspection in the middle of 

 February showed plenty of eggs, but no evidence of stem mothers ; the 

 first stem mothers were found on the fifth of March. In 1913 a very 

 few stem mothers were found as early as February fifteenth and no 

 eggs were found later than March tenth. In 1914 the first stem mothers 

 were found on March sixth and eggs have been found as late as 

 March sixteenth. 



The experimental control work for this season has been largely with 

 a five per cent solution of commercial lime-sulphur spray, with which 

 has been used in many cases a certain amount of additional lime to 

 serve as an indicator. The work last season was sufficient to show that 

 the aphis can be completely controlled by this spray. The work this 

 season has been planned to show whether or not spraying is practical 

 from the standpoint of cost, and how much actual damage will be pre- 

 vented where the aphis is held in cheek. 



This office is conducting spraying experiments on three different 

 orchards. On two of these the trees were approximately seven years 

 old and of medium size for the age. In figuring the costs we have 

 charged $13.00 per day for labor, team and rental of outfit, which is 

 possibly somewhat higher than is necessary. On orchard No. 1, approxi- 

 mately ten gallons of spray were applied per tree. The cost per gallon 

 of spray applied, 1.08 cents for labor, 1.3 cents for material, make a 

 total cost of 22.3 cents per tree. In orchard No. 2 the trees were 

 slightly larger, using approximately 11 gallons to the tree, making an 

 average cost of about 25 cents. The third orchard contained some of 

 the largest trees in the county. On these trees we used an average of 

 65 gallons per tree; at a cost of 7 cents per gallon of spray applied, 

 for labor, and 1.3 cents for material, make a total of $1.30 per tree. 

 The work on these large trees was done with a long distance M.A.C. 

 nozzle, which has been used in the East for spraying shade trees for 

 browntail and gypsy moth. The pressure was from 200 to 225 pounds. 

 A slightly higher pressure would have been better, but this was the 

 capacity of the rig which we were using; a Bean Giant pump with 2h 

 horsepower engine. For the smaller trees the Friend drive-spray noz- 

 zles were used alternately Avith the M.A.C. and seemed to be equally 

 satisfactory. 



