300 INSECTS AND MAN 



the San Jos6 scale, Aspidiotus perniciosus, so called 

 because it first appeared in the New World at San Jose, 

 California. Efforts were made by American entomologists 

 to discover its original home, just as had been done in the 

 case of the cottony cushion scale. Europe was out of the 

 question, for it was unknown there ; suspicion fell on 

 Australia, Hawaii, and Japan, where the pest was rife, but 

 investigations proved that all these countries had received 

 their original supply on nursery stock imported from 

 America. In 1901 Mr Marlatt started on a tour of ex- 

 ploration to the countries of Eastern Asia, with the object 

 of discovering a control insect. Six months were spent 

 in Japan, but a thorough investigation revealed that that 

 country was not the native home of the San Jose scale. 

 Finally, its original home was discovered in Northern 

 China, in a region between the Tientsin-Pekin road and 

 the Great Wall, and its habitat a small haw apple which 

 grows wild over the hills. Everywhere in this district 

 there occurred a little ladybird, Chilocorus similis, feeding 

 on all stages of the San Jos6 scale. 



o 



Although two hundred living specimens of the beetle 

 were shipped to Washington, all but two perished during 

 the winter. One of the survivors, however, proved to be a 

 female, which commenced to oviposit in April, and from 

 this single individual two hundred eggs were obtained. 

 Subsequent generations throve so admirably that by 

 August over a thousand specimens were sent out to various 

 experiment stations in America, and at the end of the 

 summer there were still over a thousand survivors left at 

 Washington. Everything pointed to the duplication of the 

 Novius cardinalis achievements, but this was not to be. 

 Colonies in the Northern States perished, and in the South 

 the almost universal use of various washes, to destroy the 

 scale, effectually prevented the rapid multiplication of the 

 beetle, and in many cases exterminated it altogether. 

 Apart from this mitigating circumstance, there is every 



