TWENTY-NINTH FRUIT-GROWERS' CONVENTION. 



157 



sion (often imperfect) and resin wash were almost absolutely aban- 

 doned. 



The cyanide process next came forward. This, rightly used, was 

 surely thorough, as the gas went everywhere. Fumigation was long in 

 highest esteem because of its efficiency. It is true beyond contradiction 

 that fumigation, properly performed, will kill all scale insects that are 

 not too far advanced toward maturity, and that, too, without injury to 

 the trees or fruit. It is equally certain that it does not kill old or 

 mature scale, nor does it destroy the eggs. If, then, we could be sure 

 of a uniform hatch so that all the scale would be young when treated, 

 this method would surely retain its popularity. But in late years, we 

 have not had this uniform hatch. Young and old scale alike were in 

 evidence in every month of the year. We see, then, that two fumiga- 

 tions were required for extirpation, and the cost of two fumigations is 

 prohibitive. 



The points rightly urged against fumigation are: Cost; virtual 

 failure in case of want of uniformity in time of hatching; the necessity 

 of doing it at night, when the owner finds it difficult to give the Avork 

 personal supervision; the fact that it must be done by uninterested 

 parties, who will rarely exercise the caution requisite to success. The 

 fact that, in late years, the failures have almost equaled the successes 

 proves that the above points are well taken. 



In case fumigation is employed, enough cyanide must be used to 

 burn slightly the tender twigs. If this is done, and the insects have 

 hatched uniformly and are fumigated when all are young, we may 

 surely expect a very complete extirpation, and may surely expect not 

 to need to fumigate again for the next three years. If the work is done 

 by contract, the orchardist should stipulate that enough cyanide be 

 used to slightly injure the tender twigs and yet that no serious injury 

 shall be done to either tree or fruit. The carrying out of this contract 

 must precede any payment for work. The orchardist must also see to 

 it that fumigation is done when the insects are of a suitable age and 

 that the orchard is in the best condition of thrift. I think it is certain 

 that with as uniform a hatch as we have had this past season, in many 

 parts of southern California, fumigation, conducted as suggested above, 

 will be very effective and the cost not prohibitive. The fact, however, 

 that in late years the time of hatching has been so varied, has proved 

 fumigation very uncertain, and many of our best orchardists have lost 

 confidence in it and have cast about for a better method. 



We have seen that spraying with resin wash and kerosene emulsion 

 has been abandoned for years in our citrus groves. About three years 

 ago the distillate emulsion became quite popular. It was found more 

 effective than kerosene emulsion, but was soon abandoned because of 

 serious spotting of the fruit. About two years ago, the Stearns brothers 



