182 



sociation of Agricultural Colleges and Experiment Stations, it became 

 evident that what I might present in that direction would be substan- 

 tially anticipating and repeating what we may expect and hope to hear 

 from him. I will endeavor, therefore, to touch upon a few matters un 

 connected with station work. 



SOME RESULTS FROM THE NATIONAL DEPARTMENT AT WASHINGTON. 



The hydrocyanic acid gas treatment against scale-insects is becoming 

 more and more common in California, and has, to a certain extent, su- 

 perseded the use of washes, especially against the Eed Scale {Aspidiotus 

 aurayitii). This is largely due to the fact that recent experiments, car- 

 ried on through Mr. Coquillett, have resulted in a great cheapening of 

 the process. The expense has been reduced one-third, and the bulky 

 machinery mentioned in my report for 1887 has been, for the most part, 

 dispensed with. It has also been found that the use of the process at 

 night is safer and more beneficial, in that it lessens the effect of the gas 

 upon the foliage. 



The repeated importation of scale-insects from Florida into Cali- 

 fornia has attracted much attention. The species concerned are princi- 

 pally the Purple Scale {Mytilaspis citricola), the Long Scale {M. gloverii)^ 

 and the Chaff Scale {Parlatoria pergandei). The face that these insects 

 must have been repeatedly imported into the State in past years without 

 obtaining a foothold has been used as an argument against a quaran- 

 tine, and a great deal of discussion on the subject has been had in the 

 California papers. From my own observations in the State I am con- 

 vinced that where the proper conditions of shade and moisture obtain 

 there is no 'reason why these scale insects should not get a foothold, but 

 that they will probably die out in the hotter, drier, and less shaded 

 localities. An agent who was sent to Pomona to investigate certain 

 newly planted orange groves of Florida trees found that while the trees 

 were planted a year previously and had been dipped according to cus- 

 tom there in a caustic solution, every tree examined by him bore a few 

 specimens of the purple scale. The excitement on this subject in Cali- 

 fornia has been fostered by the claims of rival nurserymen engaged 

 either in the importation of Florida stock or dealing in varieties grown 

 at home, and from such contrary claims from persons prejudiced by 

 their business interests it is difficult to extract the truth. A rigid quar- 

 antine not absolutely prohibitive were wisest, for great injustice might 

 be worked by absolutely prohibitive restrictions. Careful inspection 

 and thorough treatment, if they could be guarantied, would prove an 

 effective safeguard, but it were unsafe to trust to them without a rigid 

 quarantine. 



I have commenced a series of experiments upon the Black Scale {Le- 

 canium olece), a species which, ordinarily occurring upon the Olive, has 

 long damaged citrus fruits in California. The horticulturist of the Wis- 

 consin Station, Mr. E. S. Goff, has modified the Nixon pump by adding 



