Insects in Orchid Houses. 109 
hour’s carrot-bed ; every carrot lias been ruined ; his bed is utterly 
ruined.” Together with the work of the Carrot Fly in this neigh- 
bourhood was a bad attack of Aphis. “ People about here, writes 
Mr. Hammond, “ are complaining that their carrots are very much 
infested with Aphides at the roots.” This was early in October. 
By the 20th Mr. Hammond found that they had nearly all dis- 
appeared. They are to be found generally on the crown of the 
carrot ; they do not cause the cracks, but shelter in them. These 
Aphides were too shrivelled to identify when they arrived ; they 
were probably Schizoneura fodiens. 
Correspondence and Report on Insects in Orchid 
Houses. 
Gatton Park, Surrey, 
8th July, 190% 
To Professor E. Ray Lankester, M.A., etc., 
Natural History Museum, South Kensington, S.W. 
My Dear Sir, — I am a collector of orchids and somewhat largely 
interested in their hybridization, but our efforts are materially interfered 
with by a little fly or its grub (specimens of which I enclose), and whose 
ravages we have found no means of preventing. It is no uncommon 
thing for them to clear off the whole of the contents of a pot of seed as 
soon as it is sown and germinates. We have made the following observa- 
tions in regard to it : — 
They seem to frequent and thrive most where they have damp moss to 
dwell in, which unfortunately is an essential feature of successful orchid 
growing. 
Being often found on plants that have no seed on them, they of course 
have other food, but apparently they have largely increased in my houses, 
which, however, may be due rather to the amount of moist moss about than 
to the amount of orchid seed which they have to feed on. They are 
equally troublesome in what we know as the “ Cool House ” (50° to (>0° F.) 
as in the hot ones (65° to 85° F.). They devour the seed immediately it 
commences to germinate, and if not devoured in this stage they attack 
the small bulblet as soon as it is formed, eating it from the base and 
leaving the shell only. They are harmless to plants after the early stages 
and so are not troublesome to orchid growers generally. 
Careful search has failed to discover a grub. Hence it is assumed 
(possibly erroneously) that it is the fly which does the mischief. Further, 
the winged one (? male) is rarely found on the pots, which leads to the 
assumption that it is the wingless one which does the mischief. If we are 
wrong in the assumption that the male only has wings our observation 
would lead to the suggestion that the fly is harmful only before it develops 
its wings. The body of the wingless one on the pots is much larger than 
the one found with wings. AVhen the seed is sown on a flat surface 
without harbour we are not troubled ; but directly the seed is removed, 
which it has to be soon after germination, it becomes liable to attack. 
