REPORT ON THE SOALE-IXSECTS OF CALIFORNIA. 



By D. W. Coquillett. 



LETTER OF SUBMITTAL. 



Los Angeles, Cal., October 17, 1891. 



Sir : I herewith submit my annual report for the year 1891, consisting of notes on 

 the principal kinds of scale-insects found in this State, together with the remedies 

 employed for their destruction. 



The Fluted or Cottony- cushion Scale {leery a purchasi Mask.) has been kept in 

 subjection by the Australian Ladybird (Fedalia cardinalis Muls.) first imported into 

 southern California by this Division under your direction. The propagating houses 

 erected at San Gabriel by our State Board of Horticulture at the suggestion of its 

 president, and especially intended to preserve these Ladybirds from being destroyed 

 by the inclement weather of the winter season, were not stocked with the lady- 

 birds until nearly half of the winter season had passed by ; from these houses a great 

 many colonies of these useful insects were distributed to various parts of the State 

 during the first half of the year, but none are in either of the houses at the present 

 time and I am informed that none will be on hand for distribution before next March. 

 Fortunately, however, Mr. A. F. Kercheval, of this city, formerly the President ol 

 our County Board of Horticulture, infested with the Iceryas a large patch of nettles 

 growing in the hills, several miles from any cultivated orchard, and later, after the 

 Iceryas had become very numerous upon these nettles, he introduced a uumber of 

 the ladybirds among them, so that at the present time these ladybirds can be ob- 

 tained from this source in sufficent numbers to meet all local demands. In accord- 

 ance with your instructions I had a tent erected over an orange tree in this city for 

 the purpose of breeding a sufficient number of Iceryas to serve as food for the Lady- 

 birds intended to be sent to foreign countries, since I have heretofore found it quite 

 impossible to obtain sufficient of these for this purpose from other sources. 

 Respectfully yours, 



D. W. Coquillett. 



Prof. C. V. Riley, 



U. S. Entomologist. 



NOTES ON SCALE INSECTS. 



In this State there is no class of insects more destructive to fruit 

 trees than those commonly known as scale insects. Other insects may 

 occasionally strip the tree of its leaves or rob it of its fruit, but none 

 appear over such wide areas and cause such widespread destruction to 

 the trees themselves as do these insidious, highly destructive pests. 

 Up to the present time but little has been written upon the habits and 



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