51 



sanguine expectations had been surpassed by this species. He tele- 

 graphed under date of August 28 that it is established in every county 

 south of Concepcion, that it is very plentiful in Los Angeles and San 

 Diego counties, and that he is still sending it out from his office in San 

 Francisco. The Los Angeles commissioners had also by that time dis- 

 tributed over 400 strong colonies near Escondido, and stated that the 

 insect was spreading naturally and rapidly from the points of distribu- 

 tion, and as a result there was a feeling of great confidence among 

 orchardists. 



The writer spent portions of November and December in California, 

 and particularly investigated the status of this parasite. A visit to 

 the office of the horticultural commissioners of Los Angeles Count}^ 

 November 27, 1903. enabled him to note the process of breeding and 

 shipment of colonies of the Scutellista. The secretary of the board, 

 Mr. Jeffrey, stated that 1,000 colonies had been sent out from his 

 office, and that probably as many more had been distributed directly 

 from orchards. 



The principal source of supply at this season was the pepper trees. 

 Hitherto these trees have been rather maligned as harboring the black 

 scale, and facilitating the reinfestation of adjoining citrus and olive 

 orchards, but with the introduction of the Scutellista this tree plays a 

 very useful role, because the black scale upon it seems to breed more 

 irregularly, at least in some regions, than on the orange, and hence 

 supplies food in the proper stage for the parasite over a much longer 

 period than is the case with citrus trees. 



The Scutellista larva feeds only on the eggs, and never has been 

 discovered to attack the young or gravid female host insect. It is 

 therefore desirable that the scale should be present in the egg stage at 

 practically all seasons of the } T ear to allow the parasite to go on breed- 

 ing unchecked. There is some evidence, however, as will be shown 

 later, that the parasite may have a resting period corresponding to the 

 winter months, during which the great mass of the black scale is in 

 the larval stage, thus accommodating itself to the habits of its host. 



It will be apparent that the usefulness of this parasite depends on 

 how nearly it destiws all of the eggs produced by the female Leca- 

 nium, and it is very interesting, in this connection, that the repeated 

 examinations made by Mr. Jeffrey and others and by the writer 

 revealed in no instance the escape of a single egg in a parasitized scale. 

 If the eggn are few in number the parasite comes to full development, 

 but yields a much smaller insect; on the other hand, a large, well-fed 

 female scale will develop a parasite of unusually large size, but the 

 larva in either case seems to continue feeding as long as there are an}^ 

 eggs to be devoured. 



A common method of distributing the parasite is to cut branches 

 from pepper trees and tie them to the orange trees in various places 



