360 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 32 



collected and brought to California, and of these 129 arrived alive. 

 These reproduced so rapidly that millions were available in a rela- 

 tively short time. They were distributed throughout the groves 

 in Southern California and in two years the menace of the cottony- 

 cushion scale disappeared. To the present day there has been no 

 serious outbreak of the scale in the State. Occasional small out- 

 breaks do appear, but these are quickly found by the Vedalia and 

 disappear within a few weeks or months. 



This little Vedalia beetle has undoubtedly saved the growers of 

 California millions of dollars each year, while the cost of importing 

 it Avas only $1,500. Since the time of the appearance of the cottony- 

 cushion scale in California this scale has spread to various countries 

 throughout the world, to Japan, Spain, France, Italy, Egypt, and 

 practically every region in which citrus is grown. Into each of these 

 countries in turn the Vedalia has been introduced and has repeated 

 the success first achieved in California. 



The striking results secured with Vedalia served as a stimulus to 

 this type of work against many insects and in many countries. 

 Similar world-wide distribution has taken place in the case of 

 Prospaltella, which is a parasite of the scale insect Diaspis penta- 

 gona, found on peach and other fruit trees, and Aphelinus vmli, 

 parasitic in the woolly ajohis upon apple trees. The success, however, 

 has not been so uniform as was the case with Vedalia. 



At the present time the importation of parasites and predators 

 IB one phase of the program for the control of practically all of 

 our more important insect pests which have gained entry from other 

 countries. For the last 25 years the natural enemies of the gipsy 

 moth have been studied in various parts of Europe and Asia and 

 a very large number of species have been shipped to the United 

 States and tested. An extensive series of parasites has become well 

 established and has had a very appreciable effect upon the moth 

 infestation. 



Another foreign insect which has become most destructive in this 

 country is the so-called Japanese beetle, which was first found in 

 New Jersey in 1916 and has since spread over a wide area. The 

 search for the parasites of this beetle has been in progress for 13 

 years, and more than 1,000,000 parasites, of 24 species, have been 

 imported from Japan, Chosen (Korea), China, and India. 



The work to date upon this beetle illustrates very well the disap- 

 pointments whicli are often experienced in parasite-introduction 

 work. In northern Japan there was found a fly {Genteter cinerea) 

 which in alternate years destroyed 90 per cent or more of all beetles 

 in the field within two weeks after their emergence. From a study 

 of conditions in northern Japan it seemed quite evident that the 

 beetle was kept within reasonable bounds solely by this parasite, and 



