50 Indian Museum Notes. [ Vol. III. 



have been so unfavourable that it is not surprising the plant has attract- 

 ed but little attention in this connection. It will be interesting 

 therefore to ascertain whether subsequent experience confirms thu 

 favourable opinion formed of the decoction by Mr. Weston. 



A small quantity of some London purple, supplied to the Indian 

 London purple insecticide Museum for experiment by Messrs. Kem- 

 in Madras - ingway & Co., of London 'and New York., 



also a force pump similarly supplied for experiment by Messrs. Kumsey 

 & Co., of New York, were forwarded to the Madras Museum in 

 January 1889 for experiment upon the caterpillar Achce melicerte Drury, 

 which was reported as doing" a considerable amount of damage to castor 

 oil plants in the Madias Presidency. The insecticide seems to have 

 reached Madras too late for use against this caterpillar, but a report ha? 

 been furnished, through the Madras Board of Revenue, of some expe- 

 riments made with, it by the Government Botanist in July 1891. These 

 experiments were made upon scale insects, red spider, and Aphidse, for 

 which London purple is not usually recommended, as they all feed by 

 drawing up the juices of the plant through a narrow proboscis which is 

 inserted into the tissues of the leaf or shoot. They are therefore little 

 effected by a poison like London purple, which usually requires to be 

 taken into the stomach, though cases have been found, as for instance, 

 that of the leaf hopper which attacks mango blossom, where it is effec- 

 tive against haustellate insects. It is to be hoped that in the further 

 experiments which it has been proposed to make in the College of Agri- 

 culture, Madras, attention will be chiefly directed to mandibular insects, 

 such as caterpillars and beetles, which eat the substance of the plants and 

 are thus likely to take the London purple into their digestive organs. 



The following is an extract from the report furnished by the Gov- 

 ernment Botanist, on experiments made with the force pump and 

 London purple furnished to the Madras Museum : — 



" The results have not been so satisfactory as I expected ; a strong solution failed 

 to kill scale; a weaker solution proved destructive to red spider and aphids, when 

 the fluid was brought in contact with them ; but the insects on the under surface of 

 the leaves were often untouched by the spray and so escaped. The stronger solution 

 killed the leaves of the plants to which it was applied. The solution itself is no doubt 

 a ireful insecticide, and it is the method of applying it only which is not quite 

 satisfactory, as the pump is not suited for directing the spray to the under surface 

 .of the leaves. " 



An interesting report on the sugarcane borer (Diatrcea saccharahs 



Fabr.), by Mr. L. O. Howard, appears in Insect 

 Sugarcane borer. ^ ^ ^ ^ Waghingtpilj le9 l. 



