xiv Remedial Measures and Insecticides. 



where in S. America ; and there is evidence in favour of the sup- 

 position that we owe our 'green coffee bug' {Lecanitcm viride) 

 to Western Africa. Aspidiotus cydonice, Chionaspis biclavis, and 

 Mytilaspis citricola were originally described from America. 

 Aspidiotus ca?nellice, A. cyanophylli, CJnonaspis aspidistra;, and 

 Dactylopius citri, are all well known on the continent of Europe. 

 Aspiodotus aurantii and Pulvinaria psidii have their home in 

 Australasia. Our former coffee pest, the ' brown bug' [Lecanium 

 coffcce) might perhaps be quoted as an exception to this rule, as it 

 was first recorded from Ceylon. But this insect is now considered 

 to be merely a local variety of Lccanimn JieinispJueriann, an insect 

 found all over the world, and whose origin is uncertain. On the 

 other hand, not a single undoubtedly native species has attracted 

 any notice as an insect pest in Ceylon. 



We have only to recognise these facts to appreciate the im- 

 portance of a properly conducted system of quarantine for all 

 imported plants and fruit. Our insular position in Ceylon, with 

 but one main port of entry, gives us a peculiar advantage in 

 carrying out such a system. A single quarantine station, with 

 a single fumigatorium, will be sufficient in our case to deal with 

 the whole importations of the island. It is true that, in spite of 

 quarantine regulations, particular pests have found their way into 

 protected countries. In such cases failure must be attributed to 

 incompleteness of execution. And, though some {q.\v pests may have 

 evaded all precautions, how many others must have been refused 

 entry t The records of existing quarantine establishments give 

 long lists of dangerous insects detected on arrival, and destroyed 

 before they have had the chance of obtaining a footing in the new 

 country. I believe it is the custom at most quarantine stations 

 to examine imported plants and fruit, and, if they appear to be 

 free from blights, to pass them without treatment. But I maintain 

 that not even the most experienced entomologist could guarantee 

 a plant as absolutely free from insect life. Minute larvae and eggs 

 may lurk beneath bud-scales, in the axils of leaves, or in unnoticed 

 crevices of the bark. To be really effective, quarantine must be 

 complete. Every live plant and fresh fruit should be subjected to 

 treatment, whether it appear to be free from disease or not. 



The only sure way of reaching every hidden insect is by fumi- 

 gation. If properly conducted, there is little danger of permanent 

 injury to the plant. Even though some few delicate plants may be 

 injured, or actually killed by the process, this is a very small 



