ANIMALS INTRODUCED FOR SAKE OF UTILITY 261 



generations, it was found that they had increased so greatly 

 in numbers that some could be distributed and set free in 

 the hope that they would become naturalized and seek to 

 feed, as they did in their own country, upon the Scale- 

 insects. The result was a triumph for scientific investiga- 

 tion, for the Australian Lady-birds settled comfortably down 

 to their labours and multiplied so satisfactorily under natural 

 conditions in the orange groves of California, that in a few 

 years the increase of the Scale was checked, and ever since 

 it has been held in subjection. Solely on account of its utility, 

 this fine Lady-bird has been added, not only to the fauna of 

 America, but, since its value there was tested and proved, 

 to the faunas of South Africa and Egypt, where it has 

 achieved similar excellent results. 



Other Lady-birds have been introduced into the United 

 States to fight various Scale-insects, one of which, the San 

 Jose Scale (Aspidiotus perniciosus}, first imported from 

 China, caused terrible destruction in American orchards in 

 the early nineties of last century. Careful observation 

 showed that a Lady-bird (Chilocorus similis), common to 

 China and Japan, was the most efficient counter to 

 the Scale in its native haunts. A larval beetle has been 

 seen to eat six Scales a minute, and, since it never seemed 

 to weary of its repast, about 8000 a day. The Lady-birds 

 were transported from the far East to the United States 

 where they were bred, distributed and set free in great 

 numbers, to the discomfiture of the Pernicious Scale. 

 This introduction, however, finally died out in its new 

 country. 



A last and more recent illustration of the influence of 

 the counter-pest method in adding to a country's inhabit- 

 ants is that concerning the Mulberry Scale of Japan (Aulq- 

 caspis pentagona}. This Hemipterous insect, like other 

 Scales, attacks the outer surface of trees, which it pierces 

 in order to abstract the plant juices within. It is almost an 

 omnivorous pest, for in a limited area it has been found on 

 as many as 50 different kinds of trees, but its greatest dam- 

 age is worked on peach-trees, plum-trees, and in southern 

 Europe on mulberry trees. From Japan the Mulberry Scale 

 has been carried on young trees to all parts of the world, 

 and in most countries it has become naturalized and has 



