261 



Speyer (E. R). Committee of Agricultural Experiments. Shot-hole 

 Borer of Tea. — Trop. Agriculturist, Peradeniya, lii, no 2, February 

 1919, pp. 65-69. 



As a remedy against the shot- hole borer of tea [Xyleborus fornicathis] 

 an experiment was tried in painting bushes immediately after pruning 

 with the following mixtures :■ — (a) resin-soap fish-oil emulsion, with 

 excess of resin ; (b) resin-soap fish-oil emulsion ; (c) resin-soap fish-oil 

 kerosene emulsion ; (d) resin-soap kerosene emulsion. An equal number 

 of trees were treated with each mixture between 4th and 10th December 

 1918 ; when examined a month later the galleries in the areas treated 

 with (a) and (b) were vacant ; in the galleries of plants treated with 

 (c) and (d) a few living beetles were found, but no young stages. 

 The untreated areas contained all stages as well as beetles commencing 

 new galleries. In both areas a number of galleries had been vacated 

 naturally, but among the treated plants even those in process of 

 construction were found empty, so that the insecticidal properties 

 of (a) and (b) are evident. The excess of resin was found unnecessary. 

 The only detrimental effect noticed on the plants was that the growth 

 of new shoots is retarded for about 7-14 days. The efficacy of the 

 mixture as a preventive measure was confirmed by an experiment in 

 the laboratory. It was also ascertained that fish oil, but not kerosene, 

 acts as a definite deterrent. The quantities advised per acre of tea 

 are 27 lb. of the solid emulsion dissolved in 8 gallons of water. When 

 the fields are again in flush the insects, once treated by the above 

 method, may be easily controlled by cutting out the infested branches, 

 but this should not continue after 6 months before the following 

 pruning. 



Work connected with Insect and Fungus Pests and their Control. — Imp. 

 Dept. Agric. West Indies, Report Agri'c. Dept. Dominica, 1917-1918, 

 Barbados, 1919, pp. 11-17. [Received 21st April 1919.] 



At the beginning of 1915 spraying of young lime trees was discon- 

 tinued to judge the efficacy of natural methods of control ; as a result 

 several species of scale-insects became very abundant and checked 

 the development of the trees ; though spraying was not resumed, 

 the loss occasioned was replaced by the rapid growth due to the 

 remedial measures employed in the form of thorough draining and 

 cultivation and the application of a small quantity of lime and then 

 of organic manure at the rate of 2 lb. per tree. It is considered, there- 

 fore, that these measures, accompanied by the provision of a shelter 

 crop such as Tephrosia Candida, are the best means of protecting 

 young lime trees from infestation by scale-insects. 



Puncheons and other packages used for exporting lime juice have 

 been severely attacked by borers belonging to the genus Xyleborus 

 and allied genera. Infested timber may be treated by placing it in 

 an air-tight chamber into which steam is forced until a temperature 

 of 118° to 125° F. is reached or by fumigation with carbon bisulphide ; 

 to prevent reinfestation naphthaline should be scattered around the 

 material ; carbolineum should not be used for this purpose as it is 

 liable to taint the lime juice. 



The mango crop during 1917 suffered from an abnormal outbreak 

 of a species of fruit-fly not yet identified. The eggs are inserted 



