48 PRESENT-DAY GARDENING 



is one of the best means of preventing Orchid diseases, 

 and efforts should be made to keep the plants vigorous and, 

 therefore, capable of resisting attacks by insect pests. 



Plants are also benefited greatly by having their position 

 in the houses changed, and that is one of the great advan- 

 tages of the periodical inspection, for during this process 

 the relative positions of the plants are altered. 



It should be said that Cattleyas and other common 

 Orchids badly affected by disease had better be burnt, for 

 it is cheaper to buy a healthy young plant than to waste 

 time in trying to bring the unsightly and diseased specimens 

 back to health. 



The Cattleya Fly (Isosoma orchidearum), first im- 

 ported probably with Cattleya Dowiana, and frequently 

 with other Cattleyas since, affects the new growths, the 

 grubs causing them to swell and rendering the growth use- 

 less. The same species, or one closely allied, also attacks 

 the young roots of Cattleyas, Lselias, and their hybrids, 

 causing unsightly galls on the points of the roots. Fumi- 

 gation, with some safe preparation to destroy the fly, should 

 be carried out, and every young growth and root-point as 

 soon as they are seen to be affected should be cut off 

 and burnt. By adopting these remedies it is possible 

 to get rid of the pest. In purchasing freshly imported 

 plants, care should be taken to reject those which show 

 signs of having been affected by the fly. 



Thrips, Red Spider, and Aphides occasionally appear in 

 every collection, and the remedy is fumigation and sponging 

 with an insecticide, which some growers prepare for them- 

 selves, either by pouring boiling water over coarse tobacco 

 tied up in a cloth and adding a little soft soap, or by 



