Remedial Measures and Insecticides. xxxix 



bodied species that are unprotected by a covering scale, such as 

 Lecaniuui viride, Pulviuaria psidii, and Dactylopius citri. It has 

 little or no effect against the Diaspidince. 



Lime Water. — In the early days of the 'green coffee bug' I 

 used a very thin wash of quick-lime and water. The mixture is 

 inconvenient or difficult to apply as a spray, as it quickly clogs the 

 nozzles and valves of the machine. I applied it with large brushes 

 to the affected coffee foliage, and it was certainly fatal to every 

 insect with which it came in contact. The bugs turned from green 

 to a bright orange colour within five minutes of the application. 

 But many individuals necessarily escaped, and the benefit was only 

 temporary. No damage to the trees was observed, but the lime 

 had such a caustic effect upon the hands and arms of the coolies 

 employed in the work that it had to be discontinued. 



Strazvson's Mixtures. — I have recently had the opportunity of 

 experimenting with a mixture supplied by the Strawson Company 

 for use against the Tea-mite, and have found it very effective 

 against scale insects of all kinds. It is one of the few insecticides 

 that I have found of real value against Orthezia. Applied as a 

 spray in the strength of \\ lbs. to 4 gallons of water, it not only 

 kills this insect, but prevents the hatching of the eggs also. This 

 is apparently effected by the blocking of the aperture of the ovisac, 

 and so preventing the emergence of the young insects. The 

 mixture (as supplied) is of a soapy nature, and it is the soap that 

 is probably the active agent in the destruction of the scale insects. 

 The ingredients are naturally kept secret by the manufacturers, 

 for which reason I am unable to recommend its use as a spray for 

 tea during the ' plucking ' season, but for the removal of scale 

 insects upon other trees it will be found of value, and I have 

 frequently used it advantageously to clean the stems of pruned 

 tea. It is particularly effective also against the ants {Creniasto- 

 gaster Dohnii) that give such trouble by building their nests in the 

 tea bushes. These nests always enclose a colony of scale insects 

 (usually Lecanium formicarii), and to prevent the recurrence of the 

 ants it is most necessary to get rid of the bugs that attract them. 

 For application to the stems of trees a large paint brush can be 

 used in place of the spraying machine. 



McDougaVs Insecticide Wash. — This is another very useful 

 patent insecticide, also of a soapy nature. As the ingredients are 

 kept secret, the same objection applies to its extensive employ- 

 ment upon tea plants. It is equally effective against scale insects. 



