1907.] PUBLIC DOCUMENT No. 73. 125 



elapse before they are able to produce an appreciable effect. In these 

 experiments in the international transportation of beneficial insects, ex- 

 perience has shown that even after a long lapse of time species sup- 

 posed to have died out will suddenly become noticeable, and will do 

 good work. 



A marked instance of this character was brought to my attention last 

 month, while on an official trip in southern California. In 1889 Albert 

 Keobele was sent to Australia by the United States Department of 

 Agriculture to collect and import the natural enemies of the white or 

 fluted scale (Icerya purchasi). The parasite of which we had definite 

 knowledge through correspondence with an Australian entomologist, the 

 late Frazier S. Crawford, was a minute fly known as Lestophonus 

 iceryce Will. Mr. Koebele succeeded in securing this parasite and in 

 sending it to California, and he also secured the now famous Vedalia 

 (Novius) cardinalis, a ladybird beetle which multiplied enormously and 

 destroyed the scale insect within a year after its arrival in California. 

 The Lestophonus, however, apparently died out, and nothing was heard 

 of it or seen of it, apparently, so far as the published records go, from 

 1890 until the present year. It now appears to have multiplied ex- 

 tensively, and to be abundant in southern California. A second in- 

 stance of the same sort was the original importation by the writer of 

 Scutellista cyanea from Italy into the United States, and its coloniza- 

 tion upon the wax scale at Baton Rouge, La. This importation oc- 

 curred in the year 1895. This introduction was apparently unsuccess- 

 ful. Yet, after a lapse of eleven years, I learned only last month that 

 the Scutellista has apparently succeeded in establishing itself in Louisi- 

 ana, and it is there an effective enemy of the wax scale. 



It seems, therefore, improbable that the effort now being made to 

 establish the European insect enemies of the gypsy and brown-tail moth 

 in New England should prove a failure; and in my opinion there is 

 every reason to think, judging from what has already been accomplished, 

 that the prospects at the present time are very good. Surely the large 

 scale on which the importations are being made is a decided innovation 

 in this kind of work, and should bring nearer the period of relief. 



In the last report of the superintendent there was given in 

 some detail the records of each sending of parasitic material. 

 The number of shipments in 1906 was so large, however, as 

 to almost prohibit the publishing of these detailed records, 

 which are on file at the Bureau of Entomology, Washington, 

 D. C., and the following summary, from Mr. Titus's notes, 

 will suffice : - 



We received all told 117,257 brown-tail moth webs collected from all 

 parts of Europe, a large percentage of the webs containing parasites 



