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, Lzelias, 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 
