554 REPORT OF THE COMMISSIONER OP AGRICULTURE. 



ancos, will find it to be absolutely impossible to spray the solution upon ever?/ insect 

 on the tree, as a few are quite certain to escape, protecte*]. it may be, by a curled 

 leaf or similar object. Much can be done to aid in jiroperly spraying the trees by 

 first removin.^; from the tree, especially from the inside of the top of it. all of tlie 

 branches that can possibly be spared. Tliis will not only p^reatly expedite tJie task 

 of spraying and make it more efficient, but will make a great saving in the quantity 

 of the solution required, thus lessening the cost of spraying in projiortion to the 

 number of branches removed. 



Another item of importance is to prevent the great waste of that portion of the 

 solution -wMcli ordinarily falls upon the ground after having been sprayed upon the 

 trees. Tliis can be accomplished by using some simple contrivance for catching the 

 solution in such a manner that it can be made to flow into a tub or other vessel, be- 

 ing in the mean time strained from all extraneous substances; it can then be emptied 

 into the tank or barrel to which the spraying-pump is attached and thus be used 

 over again. It has been ascertained that fully hco-thirds of the quantity of the 

 solution first used could in tliis way be saved and with but very little additional labor.*" 



As illustrating the extreme tenacity of life with which the female Cottony Cusliion- 

 scalc mstyjt is endowed, I may state a fact that I have frequently witnessed, namely, 

 that an adult female, with her egg-case attached, when sprayed with a solution so 

 caustic tiiat her back was burned black and was hard and wrinkled, still retained 

 the use of all of her organs thi-ee weeks after the application of the solution had 

 been made. In such instances the cottony egg-sac had been hardened and discol- 

 ored by the solution, and the addition to it which the female had excreted after the 

 application of the solution was very conspicuous by its whiteness. 



Several persons have succeeded in clearing their trees of the Cottony Cushion-scale 

 by simply spraying them with pui-e cold water thrown upon the trees with consid- 

 erable force, repeating the operation once or twice each week until all of the insects 

 have been removed from the trees. 



When once these msects have inserted their beaks into the bark of the ti-ee it is 

 quite impossible to exti'act them from the bark by any forcible means that we may 

 employ, as the beak is very brittle and easily broken off short to the body. It is 

 doubtless owing to tliis fact that the water remedy referred to above is so effective 

 Avhen employed against these insects, as the beaks are broken off in dislodging them 

 from the tree, and the insects, thus deprived of the organ through which their food 

 is obtained, must necessarily perish of starvation. 



Tliis method is practicable only in places where but few trees are to be treated; 

 it is much too laborious and requires repetition too frequently to be used on a large 

 scale. 



Following is a summary of the experiments which I have made with various 

 remedies for the destruction of the Cottony Cushion-scale. For spraying these 

 solutions upon the trees I used a Johnson pump and a Cyclone nozzle. 



In making these experiments it has been my aim to discover a remedy that would 

 prove fatal not only to the insects in their various stages of development but also 

 to the eggs, as it \viil be easily seen that if the latter are not destroyed they will in 

 due time hatch out, and thus again stock the ti'ee with these pernicious pests. 



Of course a remedy that merely destroys the insects could be used with good suc- 

 cess by making a second application at an interval of about two months after the 

 fii'st one, thus giving the eggs time to hatch out; but this would requu'G double the 

 labor and cost of a smgle api^Ucation and the risk of injuring the tree would also 

 be much greater. 



CAUSTIC POTASH. 



The crude potash was dissolved in water and the solution then sprayed upon the 

 trees. The cost of the potash at wholesale is about 7 cents per pound. 



One Pound of Potash dissolved in one Gallon of Water. — An hour after the applica- 

 tion the leaves upon the newest growth on the tree had sensibly withered; nine days 

 later about one-half of the leaves had dried up and fallen from the ti-ee. Two months 

 after making the application one-tenth of the smaller lateral branches had become 

 dead and dry, whUe upon the other branches a new growth had started. About 95 per 

 cent, of the insects and 60 per cent, of the eggs were killed; the insects which es- 



* Such a drain-table has already been made and used at San Jose for the purpose 

 indicated. It is described in the first report of the State Board of Horticultural 

 Commissioners, 1882, p. 83, in Mr. Chapin's report, as follows: " The table is made of 

 sheet-iron and zinc, nxed upon a frame in halves, which are placed agamst the 

 trunk of the ti-ee on either side, thus forming a chcular basin 14 feet in diameter, 

 and requiring but one minute for transfer from one tree to another. * * * The 

 saving caused by this was at least two-thirds of the material." 



