44 THE ORCHID REVIEW. 
THE CATTLEYA FLY. 
A SHORT time ago we received some pseudobulbs of Cattleya labiata from 
a collection in North Devon, which were badly affected with the Cattleya 
fly, and now others come from Tynemouth; also some of C. Triane. The 
plants were purchased from comparatively recent importations, and it is 
probable that the pest was thus introduced. Various measures have been 
tried to exterminate the pest, such as regular weekly fumigations, washing 
the plants with fir-tree oil, and cutting out and burning infected parts, 
but without getting rid of it. The plants are otherwise healthy. It is 
difficult to know what remedies to apply other than those already suggested 
(supra, III., pp. 183, 215, and 288), and a better knowledge of the habits of 
the insect would be useful. Smoking is manifestly useless, except when the 
perfect insect comes out, for the larve are perfectly protected by the 
enveloping tissues of the plant, and the same may be said for washing with 
fir-tree oil. Slight fumigations will kill the perfect insect, and if the time 
of its appearance were known these could be given nightly, if necessary, 
during this period. Cutting off and burning the affected parts, but in some 
cases this would mean mutilating the plant considerably. One young 
pseudobulb sent, for example, shows no less than five small circular holes 
where perfect insects have emerged, though otherwise there is very little to 
show the presence of the enemy, and only a person who has had experience 
of the insect would have previously’ detected it. Yet when the holes are 
seen, the insect has gone, and is probably laying eggs elsewhere for a 
renewal of the evil. Cutting off and burning this pseudobulb would have 
done no good, for, on making sections, the cavities where the larve lived 
are all found to be empty. On the other hand, the bulb and leaf, though 
a little damaged, are still capable of carrying on the nutrition of the plant. 
Another shows an external swelling, but no hole, and in this the white 
larve are found within the cavity. In this case burning would have been 
effectual. If such a swelling were punctured with an awl, and then a little 
fir-tree oil injected by means of a sprayer, with a slender metal tube, which 
could be inserted in the hole, the larve would be killed without sacrificing 
the pseudobulb and leaf; but the question remains whether the presence of 
the enemy could always be detected in time. It would appear that if the 
eggs are laid in the very young growths they soon become swollen, and the 
presence of the enemy is soon manifest ; but if the pseudobulb is already 
well formed, the mischief is not so easily detected. The eggs are also laid 
in the young roots, when a gall-like swelling quickly appears, which can be 
cut off with comparatively little damage to the plant. 
The insect is known as Isosoma Orchidearum, and we have collected 
together what little information seems to be on 
record respecting it for a 
future note. 
Meantime, we should be glad if those who are troubled with 
