REPORT OF THE ENTOMOLOGIST. 553 



the board. It is the dutv of this commission to divide the county into districts and 

 appoint an inspector for each district. When trees or plants are found to be infested 

 with the Cottony Cushion-scale or other injurious insect the owner is notified of 

 this fact and is requested to disinfect such trees or plants, and if he fails to do so 

 withm due time his premises are deemed a public nuisance, to be proceeded against 

 as any ordinary nuisance untU abated. 



On the 4th of August, 1885, the city council of the city of Los Angeles passed an 

 ordinance declaring trees and plants infested with the Cottony Cushion-scale within 

 the city hmits a pubhc nuisance immediately, and it also established the offices of 

 inspectors of fruit pests, whose duty it was to see that the provisions of this ordi- 

 nance were enforced. 



On the 13th of November, 1885, the board of supervisors of Los Angeles County 

 offered a reward of $1,000 for a perfect exterminator of the Cottony Cushion-scale, 

 and the horticultural commission and myself were appointed by the board to act as 

 a committee for determining the efficacy of the various remedies presented by the 

 different apphoants for the above reward. Up to the present writing there have 

 been eleven applicants for this reward, and these have made thirty-eight tests, but 

 none of these remedies have been deemed worthy of the offered reward. 



In the prosecution of my studies I have been not a little aided by the above com- 

 mission and their able corps of mspectors, to all of whom my warmest thanks are 

 due. Mr. Albert Koebele, one of the agents of the United States Division of Ento- 

 mology, has been with me part of the time, and has aided me much in the mechan- 

 ical part of my experiments. 

 Respectfully, yours, 



D. W. COQUILLETT. 



Prof. C. V. Riley, 



United States Entomologist, 



GENERAL CONSIDERATIONS. 



The great desideratum in a remedy for scale insects is that it shall kill all of the 

 insects and their eggs without producing any injury whatever to the tree or fruit, 

 and to this must be added the additional quahfication that it must be reasonably 

 cheap. A wash costing from 1 to 1^ cents per gallon would be cheap enough to 

 be extensively used, while if it should exceed 3 cents per gallon it would be beyond 

 the reach of the majority of the fruit-growers. 



It is no difficult task to discover a wash possessing any two of the above qualities ; 

 but to discover one wliich possesses the tliree properties combined is a far more 

 difficult matter. 



The remedies in common use in Southern California for the destruction of the 

 Cottony Cushion-scale consist of various liquid solutions applied to the infested 

 trees in the form of a spray. The usual appliances for performing this operation 

 consist of a force or spraying pump mounted upon a barrel or tank ; to the pump is 

 attached from one to four pieces of rubber hose from 15 to 20 feet in length, and 

 to the end of each is attached an iron tube measuring from 4 to 10 feet in length. 

 The nozzle commonly used is known as the " San Jose " nozzle, and is fastened to 

 the outer end of the iron tube above described. 



This nozzle consists of a short brass tube, upon the outer end of which is screwed 

 a brass cap having a large openmg in the top. This cap holds in place a circular 

 piece of brass, in the center of which is a small slit, through which the solution is 

 forced in the form of a fan-shaped spray. Sometimes a piece of rubber is substi- 

 tuted for the circular piece of brass in the nozzle ; it has the advantage of not be- 

 coming clogged so easily as the brass one, but is far less durable. 



The Cyclone nozzle, which has been fully described in previous reports of this De- 

 partment, has been used by a few different persons here, but these, with one accord, 

 prefer the San Jose nozzle. For thorough work, however, the Cyclone nozzle is to 

 be preferred, as it does not become clogged so easily as the San Jose nozzle, and it 

 also permits the operator to spray the leaves from all directions, the spray issuing 

 from the side of the nozzle instead of from the outer end, so that by simply turning 

 about the kon tube carrying the nozzle the spray can be thrown in all du'ections. 



This defect in the San Jose nozzle is overcome to a certain extent by means of a 

 ladder, by the use of which the tree can be sprayed both from above and from be- 

 low. For this purpose an improved ladder, mounted upon wheels, is now coming 

 into use. This can be wheeled from one tree to the other, and being provided with 

 the proper supports, does not rest against the tree itself. In this way the operator 

 can move up and down the ladder without being hindered by the branches of the 

 tree he is oiJerating upon. (See Plate V.) 



Even the most skillful operator, however, when equipped with the best of appli- 



