104 TWENTY-EIGHTH FRUIT- GROWERS' CONVENTION. 



found through recent personal investigation. In a district south of the 

 City of Los Angeles, a number of old groves, which were once badly- 

 infested with red and black scales, are now practically free from both, 

 without having been sprayed or fumigated for a period of from three to 

 five years. The pepper trees in the vicinity are also clean and bright. 



In the Santa Ana Valley of Orange County the same trees which for 

 years were condemned and destroyed in large numbers because of the 

 prolific breeding of black scales upon them, are now free from scales, 

 and instead of being an injury to our valley, they have proven a benefit, 

 inasmuch as they have served as a home and breeding-place for several 

 useful ladybirds (especially the Rhizobius ventralis, which is both para- 

 sitic and predaceous), they having found their way from these to citrus 

 trees, where they are now in considerable numbers, except where they 

 have been destroyed by recent fumigation or spray. 



After diligent search, I have been able to find only one small orange 

 orchard and a solitary lime tree that have not been sprayed or fumigated 

 within the past eighteen months. These have not been treated for more 

 than four years and are now free from all scale pests, the black scales 

 having been destroyed by the ladybirds, and the red, evidently, by the 

 golden chalcid fly which was brought into the valley some years ago 

 from San Gabriel, but whose work had attracted no attention until 

 August last, when upon investigation, it was found in greater or less 

 numbers over the entire valley. Where permitted, it is now doing a 

 wonderful work, and but for having been held in check by annual 

 fumigation or spraying, would have practically rid all orchards in the 

 valley from the red scale. 



We have also the Chinese red scale parasite, which is undoubtedly a 

 valuable one. 



In addition to the parasites mentioned, we have recently imported two 

 for the black scale: Coccophagus flaro scutcllum and the Scutellista 

 cyanea, which have been pretty well distributed throughout the State 

 by our horticultural quarantine officer and entomologist, Mr. Alex- 

 ander Craw, who has rendered such splendid service. 



We are now fighting the codling-moth and purple scale (Mytilaspis 

 citricola) with artificial means, and it would be impossible to estimate 

 the value of parasites for these pests. Recently I visited an orchard, 

 which since August last has been fumigated twice, and sprayed once 

 with distillate by the most approved method; and there are still enough 

 live purple scales left to thoroughly infest the trees within twelve 

 months, if no further treatment be resorted to. This scale fortunately 

 spreads rather slowly, but is a persistent stayer when it makes lodgment. 



Mr. Craw informs me that the State Board of Horticulture has knowl- 

 edge of the whereabouts of a parasite for the scale just mentioned, and 

 is making efforts to have it introduced. 



