COMMON THEIPS. 33 



It worked very satisfactorily, the spray being forced up 

 under the leaves, and other nozzles distributed the spray on 

 the uppersides of the leaves, so that the plants were 

 thoroughly soaked. The materials used were tobacco- 

 water and benzine emulsion; the former with good 

 results, but there is the drawback of having to strain it 

 before use. If it is used in large quantities, it should be 

 made in the winter and stored for use in the early summer, 

 when the thrips make their appearance. The benzine 

 emulsion, in the proportion of one in six, also proved very 

 effective, every insect reached by this mixture being killed 

 at once. This spray has the advantage also of being cheap. 

 Messrs. Robb were well satisfied with the results of the 

 latter mixture especially. 



Owing to the potato crops being mostly damaged, it is 

 useless to carry out any further experiments this season, 

 but early next season I will continue the experiments, 

 trying other mixtures in addition to those already used. 

 Owing to this season being very dry, the thrip pest was 

 very bad. Should next season be cooler, and the rainfall 

 larger, the damage will be considerably mitigated. I am 

 obliged to Mr. Seymour for the valuable assistance rendered 

 in connexion with the experiments." 



Prevention and Remedies. 



Under glass, the thrips are not so difficult to deal with, but 

 out-of-doors the task would appear to be almost an im- 

 possible one. In the early spring of 1909, these pests 

 covered the Cape Weed when in flower, and extended over 

 thousands of acres of Cape Weed-infested land. Whole 

 paddocks appeared to be alive with them, so that it would 

 be impossible to destroy them. 



The best plan of dealing with the pest is to keep a 

 constant watch, and spray regularly with some deterrent, 

 such as quassia chips, and to destroy all affected blooms. 

 The land should be kept well stirred, and the plants kept 

 growing as freely as possible. In small gardens and in 



18720. R 



