Horticulture.

Otago Witness, Issue 1499, 7 August 1880, Page 13

Horticulture.

DESTRUCTION OF INSEGT PfiSTS. UO THE EDITOR. Sib,— As probably few of your readers have heard of the oure for insect ravages recently proposed by Prof. Hagen, of Cambridge, Mass., and as it is one which it is desirable should be tried extensively, I think you will confer a boon on the community if you make it widely known. It oonsists in applying beer-yeast to the bodies of the insects sought to be destroyed. This may be done either by drying the light frothy material of the yeast and sprinkling it on the insects, or perhaps more effectually by applying the frothy or liquid yeast itself to the parts of the plants infected by the inseots. If the latter plan is adopted, a dry day should be chosen for the operation. Probably any form of yeast would do, but if it is specially made foi this purpose, I would suggest that a larger proportion of sugar be used than usual, and that free access of air should be permitted, as far aa this oan be done without effecting the temperature of the fermenting materials. Prof. Hagen thinkß that the miorosoopio spores of the yeast penetrate the bodies of the inseots, and produce in them the disease which he finds proves so fatal. But it appears more probable, from the researches of other eminent miorosoopists, that the yeast invariably contains the spores of other minute fungi, of kinds whioh are known to be very deadly to the ineeots exposed to the infection. I would suggest that thia simple remedy be tried— lst, on the Aphis or white blight of our | apple trees; 2nd, on those trees affeoted with < red spider ; 3rd, on the Cocoidpa or soale inseots whioh infest so many trees; 4th, on the oaterpillars of the saw-fly (commonly oalled leeobes), whioh destroy the leaves of thorn, cherry, and plum trees during the months of January and February. In fact, it will probably be found fatal to all forms of inßeot life. All that 1b required is that the yeast should be brought into oontaot with their bodies, and this oould be done by laying it on the branches or leaves affeoted, by means of a brush. If any or your readers would take the trouble to try the application to the various pests mentioned, and would carefully note the dates, modes of testing, results, <fee, and communicate them to me, daring this next season, I should feel muoh indebted to them.— l am, &c, Geo. M. Thomson. High School, Dunedin, 4th August.